Phenergan

Overview

promethazine

phenothiazine

• anticholinergic effects
• CNS depression
• decreases central histamine effects
• dopamine antagonist
• extrapyramidal effects
• hypotensive effects
• lowers seizure threshold
• photosensitivity
• prolongs QT interval (conditional)

Contraindicated

• cisapride
Phenergan (promethazine)

+

cisapride

1 interaction

Contraindicated

promethazine + cisapride

contraindicated: combo may incr. risk of QT prolongation, cardiac arrhythmias, extrapyramidal symptoms; may decr. cisapride efficacy (additive effects; antagonistic effects)

• pimozide
Phenergan (promethazine)

+

pimozide

1 interaction

Contraindicated

promethazine + pimozide

contraindicated: combo may incr. risk of QT prolongation, cardiac arrhythmias, CNS and respiratory depression, psychomotor impairment, seizures, extrapyramidal symptoms, anticholinergic adverse effects (additive effects)

• potassium chloride
Phenergan (promethazine)

+

potassium chloride

1 interaction

Contraindicated

promethazine + potassium chloride

contraindicated w/ solid potassium formulations; consider alternative, incl. liquid potassium formulations: combo may incr. risk of GI ulcerative, stenotic lesions (GI transit delayed, increased local exposure to high potassium concentration)

• potassium citrate
Phenergan (promethazine)

+

potassium citrate

1 interaction

Contraindicated

promethazine + potassium citrate

contraindicated w/ solid potassium formulations; consider alternative, incl. liquid potassium formulations: combo may incr. risk of GI ulcerative, stenotic lesions (GI transit delayed, increased local exposure to high potassium concentration)

• thioridazine
Phenergan (promethazine)

+

thioridazine

1 interaction

Contraindicated

promethazine + thioridazine

contraindicated: combo may incr. risk of QT prolongation, cardiac arrhythmias, hypotension (including orthostasis), CNS and respiratory depression, psychomotor impairment, seizures, anticholinergic and other adverse effects (additive effects, duplicate therapy)

Avoid/Use Alternative

• 5-HTP
Phenergan (promethazine)

+

5-HTP

1 interaction

Avoid/Use Alternative

promethazine + 5-HTP

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment (additive effects)

• aclidinium inhaled
Phenergan (promethazine)

+

aclidinium inhaled

1 interaction

Avoid/Use Alternative

promethazine + aclidinium inhaled

avoid combo: combo may incr. risk of anticholinergic adverse effects (additive effects)

• aldesleukin
Phenergan (promethazine)

+

aldesleukin

1 interaction

Avoid/Use Alternative

promethazine + aldesleukin

avoid combo: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, severe or life-threatening hypotension, seizures (additive effects)

• alfentanil
Phenergan (promethazine)

+

alfentanil

1 interaction

Avoid/Use Alternative

promethazine + alfentanil

use alternative or monitor BP, respiratory rate; decr. alfentanil dose by at least 25-50%, consider decr. promethazine dose: combo may incr. risk of profound CNS and respiratory depression, psychomotor impairment, severe hypotension (including orthostasis, syncope), seizures, severe constipation, paralytic ileus, urinary retention (additive effects)

• allopurinol
Phenergan (promethazine)

+

allopurinol

1 interaction

Avoid/Use Alternative

promethazine + allopurinol

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment (additive effects)

• almotriptan
Phenergan (promethazine)

+

almotriptan

1 interaction

Avoid/Use Alternative

promethazine + almotriptan

use alternative or monitor respiratory rate, decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment (additive effects)

• alprazolam
Phenergan (promethazine)

+

alprazolam

1 interaction

Avoid/Use Alternative

promethazine + alprazolam

use alternative or monitor respiratory rate; decr. dose of one or both drugs, use lowest effective doses and shortest duration of concomitant tx: combo may incr. risk of profound CNS and respiratory depression, psychomotor impairment (additive effects)

• amantadine
Phenergan (promethazine)

+

amantadine

1 interaction

Avoid/Use Alternative

promethazine + amantadine

use alternative or monitor respiratory rate, BP; decr. dose of one or both drugs: combo may incr. risk of CNS depression, psychomotor impairment, anticholinergic adverse effects, hypotension, including orthostasis, syncope; may decr. phenothiazine efficacy (additive effects; antagonistic effects)

• amifampridine
Phenergan (promethazine)

+

amifampridine

1 interaction

Avoid/Use Alternative

promethazine + amifampridine

consider alternative: combo may incr. risk of seizures (additive effects)

• aminolevulinic acid topical
Phenergan (promethazine)

+

aminolevulinic acid topical

1 interaction

Avoid/Use Alternative

promethazine + aminolevulinic acid topical

avoid combo: combo may incr. risk of photosensitivity reaction (additive effects)

• amitriptyline
Phenergan (promethazine)

+

amitriptyline

1 interaction

Avoid/Use Alternative

promethazine + amitriptyline

use alternative or monitor respiratory rate, BP; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, seizures, hypotension (including orthostasis), extrapyramidal symptoms, hyperpyrexia, anticholinergic adverse effects (additive effects)

• amoxapine
Phenergan (promethazine)

+

amoxapine

1 interaction

Avoid/Use Alternative

promethazine + amoxapine

use alternative or monitor respiratory rate, BP; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, seizures, extrapyramidal symptoms, hypotension (including orthostasis), anticholinergic adverse effects (additive effects)

• apomorphine
Phenergan (promethazine)

+

apomorphine

1 interaction

Avoid/Use Alternative

promethazine + apomorphine

avoid combo: combo may incr. risk of QT prolongation, cardiac arrhythmias, CNS and respiratory depression, psychomotor impairment, severe hypotension, including orthostasis, syncope; may decr. efficacy of both drugs (additive effects; antagonistic effects)

• apraclonidine ophthalmic
Phenergan (promethazine)

+

apraclonidine ophthalmic

1 interaction

Avoid/Use Alternative

promethazine + apraclonidine ophthalmic

use alternative or monitor respiratory rate, BP, decr. dose of one or both drugs if apraclonidine IOP adjunct use; postop use OK: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, hypotension (additive effects)

• aripiprazole bimonthly injection
Phenergan (promethazine)

+

aripiprazole bimonthly injection

1 interaction

Avoid/Use Alternative

promethazine + aripiprazole bimonthly injection

use alternative or monitor BP, respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, hyperthermia, extrapyramidal symptoms, seizures, hypotension, including orthostasis, syncope (additive effects)

• aripiprazole lauroxil
Phenergan (promethazine)

+

aripiprazole lauroxil

1 interaction

Avoid/Use Alternative

promethazine + aripiprazole lauroxil

use alternative or monitor respiratory rate, BP; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, seizures, hyperthermia, extrapyramidal symptoms, hypotension, including orthostasis (additive effects)

• aripiprazole monthly injection
Phenergan (promethazine)

+

aripiprazole monthly injection

1 interaction

Avoid/Use Alternative

promethazine + aripiprazole monthly injection

use alternative or monitor BP, respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, seizures, extrapyramidal symptoms, hyperthermia, hypotension, including orthostasis (additive effects)

• aripiprazole oral
Phenergan (promethazine)

+

aripiprazole oral

1 interaction

Avoid/Use Alternative

promethazine + aripiprazole oral

use alternative or monitor respiratory rate, BP; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, seizures, hyperthermia, extrapyramidal symptoms, hypotension, including orthostasis (additive effects)

• arsenic trioxide
Phenergan (promethazine)

+

arsenic trioxide

1 interaction

Avoid/Use Alternative

promethazine + arsenic trioxide

use alternative or monitor ECG: combo may incr. risk of QT prolongation, cardiac arrhythmias (additive effects)

• asenapine
Phenergan (promethazine)

+

asenapine

1 interaction

Avoid/Use Alternative

promethazine + asenapine

use alternative or monitor ECG, BP, respiratory rate; decr. dose of one or both drugs: combo may incr. risk of QT prolongation, cardiac arrhythmias, CNS and respiratory depression, psychomotor impairment, seizures, extrapyramidal symptoms, hyperthermia, hypotension, including orthostasis, syncope (additive effects)

• baclofen
Phenergan (promethazine)

+

baclofen

1 interaction

Avoid/Use Alternative

promethazine + baclofen

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, seizures (additive effects)

• baclofen intrathecal
Phenergan (promethazine)

+

baclofen intrathecal

1 interaction

Avoid/Use Alternative

promethazine + baclofen intrathecal

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, seizures (additive effects)

• bedaquiline
Phenergan (promethazine)

+

bedaquiline

1 interaction

Avoid/Use Alternative

promethazine + bedaquiline

use alternative or monitor ECG: combo may incr. risk of QT prolongation, cardiac arrhythmias (additive effects)

• brexpiprazole
Phenergan (promethazine)

+

brexpiprazole

1 interaction

Avoid/Use Alternative

promethazine + brexpiprazole

use alternative or monitor BP, respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, hypotension (including orthostasis, syncope), seizures, extrapyramidal symptoms, hyperthermia (additive effects)

• brimonidine ophthalmic
Phenergan (promethazine)

+

brimonidine ophthalmic

1 interaction

Avoid/Use Alternative

promethazine + brimonidine ophthalmic

use alternative or if elevated IOP or presbyopia use, monitor BP, respiratory rate; decrease dose of one or both drugs; OTC ocular redness use OK: combo may increase risk of CNS and respiratory depression, psychomotor impairment, hypotension (additive effects)

• brimonidine topical
Phenergan (promethazine)

+

brimonidine topical

1 interaction

Avoid/Use Alternative

promethazine + brimonidine topical

use alternative or monitor BP, respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, hypotension, including orthostasis (additive effects)

• brivaracetam
Phenergan (promethazine)

+

brivaracetam

1 interaction

Avoid/Use Alternative

promethazine + brivaracetam

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment; may alter seizure control (additive effects; antagonistic effects, promethazine may decr. seizure threshold)

• bromocriptine
Phenergan (promethazine)

+

bromocriptine

1 interaction

Avoid/Use Alternative

promethazine + bromocriptine

use alternative: combo may decr. bromocriptine efficacy; may incr. risk of CNS and respiratory depression, psychomotor impairment, hypotension, including orthostasis, syncope (antagonistic effects; additive effects)

• brompheniramine
Phenergan (promethazine)

+

brompheniramine

1 interaction

Avoid/Use Alternative

promethazine + brompheniramine

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, anticholinergic adverse effects (additive effects)

• buprenorphine
Phenergan (promethazine)

+

buprenorphine

1 interaction

Avoid/Use Alternative

promethazine + buprenorphine

use alternative or monitor respiratory rate, BP; decr. buprenorphine by at least 25-50%, consider decr. promethazine dose, use lowest effective doses and shortest duration of concomitant tx: combo may incr. risk of profound CNS and respiratory depression, psychomotor impairment, seizures, severe hypotension (including orthostasis, syncope), severe constipation, paralytic ileus, urinary retention (additive effects)

• buspirone
Phenergan (promethazine)

+

buspirone

1 interaction

Avoid/Use Alternative

promethazine + buspirone

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment (additive effects)

• butalbital
Phenergan (promethazine)

+

butalbital

1 interaction

Avoid/Use Alternative

promethazine + butalbital

avoid combo: combo may incr. risk of CNS and respiratory depression, psychomotor impairment (additive effects)

• butorphanol
Phenergan (promethazine)

+

butorphanol

1 interaction

Avoid/Use Alternative

promethazine + butorphanol

use alternative or monitor respiratory rate, BP; decr. butorphanol dose at least 25-50%, consider decr. promethazine dose, use lowest effective doses and shortest duration of concomitant tx: combo may incr. risk of profound CNS and respiratory depression, psychomotor impairment, hypotension (including syncope), seizures, severe constipation/paralytic ileus, other anticholinergic adverse effects (additive effects)

• cabergoline
Phenergan (promethazine)

+

cabergoline

1 interaction

Avoid/Use Alternative

promethazine + cabergoline

use alternative: combo may decr. cabergoline efficacy; may incr. risk of hypotension, including orthostasis, syncope (antagonistic effects; additive effects)

• cannabidiol
Phenergan (promethazine)

+

cannabidiol

1 interaction

Avoid/Use Alternative

promethazine + cannabidiol

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment; may alter seizure control (additive effects; antagonistic effects, promethazine may decr. seizure threshold)

• cannabis
Phenergan (promethazine)

+

cannabis

1 interaction

Avoid/Use Alternative

promethazine + cannabis

use alternative or monitor respiratory rate, BP; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, seizures, hypotension, including orthostasis (additive effects)

• carbamazepine
Phenergan (promethazine)

+

carbamazepine

1 interaction

Avoid/Use Alternative

promethazine + carbamazepine

use alternative or monitor BP, respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, hypotension, including syncope; may alter seizure control (additive effects; antagonistic effects, promethazine may decr. seizure threshold)

• carbinoxamine
Phenergan (promethazine)

+

carbinoxamine

1 interaction

Avoid/Use Alternative

promethazine + carbinoxamine

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, anticholinergic adverse effects (additive effects)

• cariprazine
Phenergan (promethazine)

+

cariprazine

1 interaction

Avoid/Use Alternative

promethazine + cariprazine

use alternative or monitor BP, respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, hypotension (including orthostasis, syncope), extrapyramidal symptoms, hyperthermia, seizures (additive effects)

• carisoprodol
Phenergan (promethazine)

+

carisoprodol

1 interaction

Avoid/Use Alternative

promethazine + carisoprodol

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment (additive effects)

• cenobamate
Phenergan (promethazine)

+

cenobamate

1 interaction

Avoid/Use Alternative

promethazine + cenobamate

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment; may alter seizure control (additive effects; antagonistic effects, promethazine may decr. seizure threshold)

• cetirizine
Phenergan (promethazine)

+

cetirizine

1 interaction

Avoid/Use Alternative

promethazine + cetirizine

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment (additive effects)

• chamomile, German
Phenergan (promethazine)

+

chamomile, German

1 interaction

Avoid/Use Alternative

promethazine + chamomile, German

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment (additive effects)

• chlophedianol
Phenergan (promethazine)

+

chlophedianol

1 interaction

Avoid/Use Alternative

promethazine + chlophedianol

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, anticholinergic adverse effects (additive effects)

• chlorcyclizine
Phenergan (promethazine)

+

chlorcyclizine

1 interaction

Avoid/Use Alternative

promethazine + chlorcyclizine

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, anticholinergic adverse effects (additive effects)

• chlordiazepoxide
Phenergan (promethazine)

+

chlordiazepoxide

1 interaction

Avoid/Use Alternative

promethazine + chlordiazepoxide

use alternative or monitor respiratory rate; decr. dose of one or both drugs, use lowest effective doses and shortest duration of concomitant tx: combo may incr. risk of profound CNS and respiratory depression, psychomotor impairment (additive effects)

• chlorpheniramine
Phenergan (promethazine)

+

chlorpheniramine

1 interaction

Avoid/Use Alternative

promethazine + chlorpheniramine

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, anticholinergic adverse effects (additive effects)

• chlorpromazine
Phenergan (promethazine)

+

chlorpromazine

1 interaction

Avoid/Use Alternative

promethazine + chlorpromazine

use alternative or monitor respiratory rate, BP; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, seizures, extrapyramidal symptoms, hypotension (including orthostasis, syncope), anticholinergic adverse effects (additive effects, duplicate therapy)

• chlorzoxazone
Phenergan (promethazine)

+

chlorzoxazone

1 interaction

Avoid/Use Alternative

promethazine + chlorzoxazone

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment (additive effects)

• citalopram
Phenergan (promethazine)

+

citalopram

1 interaction

Avoid/Use Alternative

promethazine + citalopram

use alternative or monitor ECG, respiratory rate; decr. dose of one or both drugs: combo may incr. risk of QT prolongation, cardiac arrhythmias, CNS and respiratory depression, psychomotor impairment, seizures (additive effects)

• clemastine
Phenergan (promethazine)

+

clemastine

1 interaction

Avoid/Use Alternative

promethazine + clemastine

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, anticholinergic adverse effects (additive effects)

• clobazam
Phenergan (promethazine)

+

clobazam

1 interaction

Avoid/Use Alternative

promethazine + clobazam

use alternative or monitor respiratory rate; use lowest effective doses and shortest duration of concomitant tx: combo may incr. risk of profound CNS and respiratory depression, psychomotor impairment; may alter seizure control (additive effects; antagonistic effects, promethazine may decr. seizure threshold)

• clomipramine
Phenergan (promethazine)

+

clomipramine

1 interaction

Avoid/Use Alternative

promethazine + clomipramine

use alternative or monitor respiratory rate, BP; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, seizures, extrapyramidal symptoms, hypotension (including orthostasis), hyperpyrexia, anticholinergic adverse effects (additive effects)

• clonazepam
Phenergan (promethazine)

+

clonazepam

1 interaction

Avoid/Use Alternative

promethazine + clonazepam

use alternative or monitor respiratory rate; decr. dose of one or both drugs, use lowest effective doses and shortest duration of concomitant tx: combo may incr. risk of profound CNS and respiratory depression, psychomotor impairment; may alter seizure control (additive effects; antagonistic effects, promethazine may decr. seizure threshold)

• clonidine
Phenergan (promethazine)

+

clonidine

1 interaction

Avoid/Use Alternative

promethazine + clonidine

if ADHD use, avoid combo; otherwise, use alternative or monitor BP, respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, hypotension, including orthostasis (additive effects)

• clorazepate
Phenergan (promethazine)

+

clorazepate

1 interaction

Avoid/Use Alternative

promethazine + clorazepate

use alternative or monitor respiratory rate; decr. dose of one or both drugs, use lowest effective doses and shortest duration of concomitant tx: combo may incr. risk of profound CNS and respiratory depression, psychomotor impairment; may alter seizure control (additive effects; antagonistic effects, promethazine may decr. seizure threshold)

• clozapine
Phenergan (promethazine)

+

clozapine

1 interaction

Avoid/Use Alternative

promethazine + clozapine

use alternative or monitor respiratory rate, BP, HR; consider decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, hypotension (including orthostasis, syncope), seizures, severe constipation, paralytic ileus (including life-threatening), other anticholinergic adverse effects (additive effects)

• codeine
Phenergan (promethazine)

+

codeine

1 interaction

Avoid/Use Alternative

promethazine + codeine

avoid combo if antitussive use; otherwise use alternative or monitor respiratory rate, BP; decr. codeine dose by at least 25-50%, consider decr. promethazine dose, use lowest effective doses and shortest duration of concomitant tx: combo may incr. risk of profound CNS and respiratory depression, psychomotor impairment, seizures, severe hypotension (including orthostasis, syncope), severe constipation/paralytic ileus, other anticholinergic adverse effects (additive effects)

• crizotinib
Phenergan (promethazine)

+

crizotinib

1 interaction

Avoid/Use Alternative

promethazine + crizotinib

use alternative or monitor ECG, electrolytes: combo may incr. risk of QT prolongation, cardiac arrhythmias (additive effects)

• cyclobenzaprine
Phenergan (promethazine)

+

cyclobenzaprine

1 interaction

Avoid/Use Alternative

promethazine + cyclobenzaprine

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, seizures, anticholinergic adverse effects (additive effects)

• cyproheptadine
Phenergan (promethazine)

+

cyproheptadine

1 interaction

Avoid/Use Alternative

promethazine + cyproheptadine

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment (additive effects)

• dantrolene
Phenergan (promethazine)

+

dantrolene

1 interaction

Avoid/Use Alternative

promethazine + dantrolene

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment (additive effects)

• daridorexant
Phenergan (promethazine)

+

daridorexant

1 interaction

Avoid/Use Alternative

promethazine + daridorexant

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment (additive effects)

• darifenacin
Phenergan (promethazine)

+

darifenacin

1 interaction

Avoid/Use Alternative

promethazine + darifenacin

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, anticholinergic adverse effects (additive effects)

• desflurane
Phenergan (promethazine)

+

desflurane

1 interaction

Avoid/Use Alternative

promethazine + desflurane

use alternative or monitor ECG, BP, respiratory rate; decr. dose of one or both drugs: combo may incr. risk of QT prolongation, cardiac arrhythmias, hypotension, CNS and respiratory depression, psychomotor impairment (additive effects)

• desipramine
Phenergan (promethazine)

+

desipramine

1 interaction

Avoid/Use Alternative

promethazine + desipramine

use alternative or monitor ECG, BP, respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, seizures, QT prolongation, cardiac arrhythmias, hypotension (including orthostasis), anticholinergic adverse effects (additive effects)

• desvenlafaxine
Phenergan (promethazine)

+

desvenlafaxine

1 interaction

Avoid/Use Alternative

promethazine + desvenlafaxine

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, seizures (additive effects)

• deutetrabenazine
Phenergan (promethazine)

+

deutetrabenazine

1 interaction

Avoid/Use Alternative

promethazine + deutetrabenazine

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of neuroleptic malignant syndrome, extrapyramidal symptoms, CNS and respiratory depression, psychomotor impairment (additive effects)

• dexbrompheniramine
Phenergan (promethazine)

+

dexbrompheniramine

1 interaction

Avoid/Use Alternative

promethazine + dexbrompheniramine

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, anticholinergic adverse effects (additive effects)

• dexchlorpheniramine
Phenergan (promethazine)

+

dexchlorpheniramine

1 interaction

Avoid/Use Alternative

promethazine + dexchlorpheniramine

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, anticholinergic adverse effects (additive effects)

• dexmedetomidine injection
Phenergan (promethazine)

+

dexmedetomidine injection

1 interaction

Avoid/Use Alternative

promethazine + dexmedetomidine injection

use alternative or monitor ECG, BP, respiratory rate; decr. dose of one or both drugs: combo may incr. risk of QT prolongation, cardiac arrhythmias, CNS and respiratory depression, psychomotor impairment, severe or life-threatening hypotension (additive effects)

• diazepam
Phenergan (promethazine)

+

diazepam

1 interaction

Avoid/Use Alternative

promethazine + diazepam

use alternative or monitor respiratory rate; decr. dose of one or both drugs, use lowest effective doses and shortest duration of concomitant tx: combo may incr. risk of profound CNS and respiratory depression, psychomotor impairment; may alter seizure control (additive effects; antagonistic effects, promethazine may decr. seizure threshold)

• dichlorphenamide
Phenergan (promethazine)

+

dichlorphenamide

1 interaction

Avoid/Use Alternative

promethazine + dichlorphenamide

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment (additive effects)

• difelikefalin
Phenergan (promethazine)

+

difelikefalin

1 interaction

Avoid/Use Alternative

promethazine + difelikefalin

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment (additive effects)

• difenoxin
Phenergan (promethazine)

+

difenoxin

1 interaction

Avoid/Use Alternative

promethazine + difenoxin

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, severe constipation, paralytic ileus (additive effects)

• dihydrocodeine
Phenergan (promethazine)

+

dihydrocodeine

1 interaction

Avoid/Use Alternative

promethazine + dihydrocodeine

use alternative or monitor respiratory rate, BP; decr. dihydrocodeine dose by at least 25-50%, consider decr. promethazine dose, use lowest effective doses and shortest duration of concomitant tx: combo may incr. risk of profound CNS and respiratory depression, psychomotor impairment, severe hypotension (including orthostasis, syncope), seizures, severe constipation, paralytic ileus, urinary retention (additive effects)

• dimenhydrinate
Phenergan (promethazine)

+

dimenhydrinate

1 interaction

Avoid/Use Alternative

promethazine + dimenhydrinate

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, anticholinergic adverse effects (additive effects)

• diphenhydramine
Phenergan (promethazine)

+

diphenhydramine

1 interaction

Avoid/Use Alternative

promethazine + diphenhydramine

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, anticholinergic adverse effects (additive effects)

• diphenoxylate
Phenergan (promethazine)

+

diphenoxylate

1 interaction

Avoid/Use Alternative

promethazine + diphenoxylate

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, anticholinergic adverse effects; may decr. phenothiazine efficacy (additive effects; antagonistic effects)

• domperidone
Phenergan (promethazine)

+

domperidone

1 interaction

Avoid/Use Alternative

promethazine + domperidone

use alternative or monitor ECG, HR, electrolytes, respiratory rate; decr. dose of one or both drugs: combo may incr. risk of QT prolongation, cardiac arrhythmias, CNS and respiratory depression, psychomotor impairment; may decr. domperidone efficacy (additive effects; antagonistic effects)

• doxepin
Phenergan (promethazine)

+

doxepin

1 interaction

Avoid/Use Alternative

promethazine + doxepin

use alternative or monitor BP, respiratory rate; decr. dose of one or both drugs; caution w/ high environmental temperature: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, extrapyramidal symptoms, seizures, hypotension (including orthostasis), hyperpyrexia, anticholinergic adverse effects (additive effects)

• doxepin topical
Phenergan (promethazine)

+

doxepin topical

1 interaction

Avoid/Use Alternative

promethazine + doxepin topical

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, anticholinergic adverse effects (additive effects)

• doxylamine
Phenergan (promethazine)

+

doxylamine

1 interaction

Avoid/Use Alternative

promethazine + doxylamine

avoid combo if doxylamine use for pregnancy-related nausea/vomiting, otherwise monitor respiratory rate: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, anticholinergic adverse effects (additive effects)

• dronabinol
Phenergan (promethazine)

+

dronabinol

1 interaction

Avoid/Use Alternative

promethazine + dronabinol

use alternative or monitor BP, respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, seizures, hypotension, including orthostasis (additive effects)

• dronedarone
Phenergan (promethazine)

+

dronedarone

1 interaction

Avoid/Use Alternative

promethazine + dronedarone

use alternative or monitor ECG: combo may incr. risk of QT prolongation, cardiac arrhythmias (additive effects)

• droperidol
Phenergan (promethazine)

+

droperidol

1 interaction

Avoid/Use Alternative

promethazine + droperidol

use alternative or monitor ECG, respiratory rate; decr. dose of one or both drugs: combo may incr. risk of QT prolongation, cardiac arrhythmias, CNS and respiratory depression, psychomotor impairment (additive effects)

• duloxetine
Phenergan (promethazine)

+

duloxetine

1 interaction

Avoid/Use Alternative

promethazine + duloxetine

use alternative or monitor respiratory rate, BP; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, seizures, hypotension, including orthostasis (additive effects)

• efavirenz
Phenergan (promethazine)

+

efavirenz

1 interaction

Avoid/Use Alternative

promethazine + efavirenz

use alternative or monitor respiratory rate; consider decr. promethazine dose: combo may incr. risk of CNS and respiratory depression, psychomotor impairment (additive effects)

• eletriptan
Phenergan (promethazine)

+

eletriptan

1 interaction

Avoid/Use Alternative

promethazine + eletriptan

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment (additive effects)

• elinzanetant
Phenergan (promethazine)

+

elinzanetant

1 interaction

Avoid/Use Alternative

promethazine + elinzanetant

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, seizures (additive effects)

• eluxadoline
Phenergan (promethazine)

+

eluxadoline

1 interaction

Avoid/Use Alternative

promethazine + eluxadoline

avoid combo: combo may incr. risk of severe constipation, paralytic ileus (additive effects)

• entacapone
Phenergan (promethazine)

+

entacapone

1 interaction

Avoid/Use Alternative

promethazine + entacapone

use alternative or monitor respiratory rate, BP; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, hypotension, including orthostasis, syncope (additive effects)

• entrectinib
Phenergan (promethazine)

+

entrectinib

1 interaction

Avoid/Use Alternative

promethazine + entrectinib

use alternative or monitor respiratory rate, BP; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, hypotension (additive effects)

• ephedra
Phenergan (promethazine)

+

ephedra

1 interaction

Avoid/Use Alternative

promethazine + ephedra

avoid combo: combo may incr. risk of QT prolongation, cardiac arrhythmias, seizures (additive effects)

• epinephrine
Phenergan (promethazine)

+

epinephrine

1 interaction

Avoid/Use Alternative

promethazine + epinephrine

use alternative or monitor BP: combo may decr. or reverse pressor effects of epinephrine (antagonistic effects)

• escitalopram
Phenergan (promethazine)

+

escitalopram

1 interaction

Avoid/Use Alternative

promethazine + escitalopram

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, seizures (additive effects)

• esketamine
Phenergan (promethazine)

+

esketamine

1 interaction

Avoid/Use Alternative

promethazine + esketamine

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment (additive effects)

• eslicarbazepine acetate
Phenergan (promethazine)

+

eslicarbazepine acetate

1 interaction

Avoid/Use Alternative

promethazine + eslicarbazepine acetate

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment; may alter seizure control (additive effects; antagonistic effects, promethazine may decr. seizure threshold)

• estazolam
Phenergan (promethazine)

+

estazolam

1 interaction

Avoid/Use Alternative

promethazine + estazolam

use alternative or monitor respiratory rate; decr. dose of one or both drugs, use lowest effective doses and shortest duration of concomitant tx: combo may incr. risk of profound CNS and respiratory depression, psychomotor impairment (additive effects)

• eszopiclone
Phenergan (promethazine)

+

eszopiclone

1 interaction

Avoid/Use Alternative

promethazine + eszopiclone

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment (additive effects)

• ethanol (alcoholic beverage)
Phenergan (promethazine)

+

ethanol (alcoholic beverage)

1 interaction

Avoid/Use Alternative

promethazine + ethanol (alcoholic beverage)

avoid combo: combo may incr. risk of profound CNS and respiratory depression, psychomotor impairment, severe hypotension (additive effects)

• ethanol (in some formulations)
Phenergan (promethazine)

+

ethanol (in some formulations)

1 interaction

Avoid/Use Alternative

promethazine + ethanol (in some formulations)

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of profound CNS and respiratory depression, psychomotor impairment (additive effects)

• ethanol injection
Phenergan (promethazine)

+

ethanol injection

1 interaction

Avoid/Use Alternative

promethazine + ethanol injection

use alternative or monitor respiratory rate, BP; decr. dose of one or both drugs: combo may incr. risk of profound CNS and respiratory depression, psychomotor impairment, severe hypotension (additive effects)

• ethosuximide
Phenergan (promethazine)

+

ethosuximide

1 interaction

Avoid/Use Alternative

promethazine + ethosuximide

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment; may alter seizure control (additive effects; antagonistic effects, promethazine may decr. seizure threshold)

• etomidate
Phenergan (promethazine)

+

etomidate

1 interaction

Avoid/Use Alternative

promethazine + etomidate

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment (additive effects)

• felbamate
Phenergan (promethazine)

+

felbamate

1 interaction

Avoid/Use Alternative

promethazine + felbamate

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment; may alter seizure control (additive effects; antagonistic effects, promethazine may decr. seizure threshold)

• fenfluramine
Phenergan (promethazine)

+

fenfluramine

1 interaction

Avoid/Use Alternative

promethazine + fenfluramine

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment; may alter seizure control (additive effects; antagonistic effects, promethazine may decr. seizure threshold)

• fentanyl
Phenergan (promethazine)

+

fentanyl

1 interaction

Avoid/Use Alternative

promethazine + fentanyl

use alternative or monitor respiratory rate, BP, ECG if anesthesia use; decr. fentanyl by at least 25-50%, consider decr. promethazine dose, use lowest effective doses and shortest duration of concomitant tx: combo may incr. risk of profound CNS and respiratory depression, psychomotor impairment, seizures, severe hypotension (including orthostasis, syncope), QT prolongation, cardiac arrhythmiassevere constipation/paralytic ileus, other anticholinergic adverse effects (additive effects)

• fesoterodine
Phenergan (promethazine)

+

fesoterodine

1 interaction

Avoid/Use Alternative

promethazine + fesoterodine

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, anticholinergic adverse effects; may decr. phenothiazine efficacy (additive effects; antagonistic effects)

• fexinidazole
Phenergan (promethazine)

+

fexinidazole

1 interaction

Avoid/Use Alternative

promethazine + fexinidazole

if possible, do not initiate fexinidazole until 5 half-lives after promethazine D/C; use alternative or monitor ECG during and x7 days after fexinidazole tx: combo may incr. risk of QT prolongation, cardiac arrhythmias (additive effects)

• flibanserin
Phenergan (promethazine)

+

flibanserin

1 interaction

Avoid/Use Alternative

promethazine + flibanserin

use alternative or monitor respiratory rate, BP; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, severe hypotension, including syncope (additive effects)

• fluoxetine
Phenergan (promethazine)

+

fluoxetine

1 interaction

Avoid/Use Alternative

promethazine + fluoxetine

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, seizures (additive effects)

• fluphenazine
Phenergan (promethazine)

+

fluphenazine

1 interaction

Avoid/Use Alternative

promethazine + fluphenazine

use alternative or monitor respiratory rate, BP; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, seizures, extrapyramidal symptoms, hypotension (including orthostasis), anticholinergic adverse effects (additive effects, duplicate therapy)

• flurazepam
Phenergan (promethazine)

+

flurazepam

1 interaction

Avoid/Use Alternative

promethazine + flurazepam

use alternative or monitor respiratory rate; decr. dose of one or both drugs, use lowest effective doses and shortest duration of concomitant tx: combo may incr. risk of profound CNS and respiratory depression, psychomotor impairment (additive effects)

• fluvoxamine
Phenergan (promethazine)

+

fluvoxamine

1 interaction

Avoid/Use Alternative

promethazine + fluvoxamine

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, seizures (additive effects)

• fosfomycin injection
Phenergan (promethazine)

+

fosfomycin injection

1 interaction

Avoid/Use Alternative

promethazine + fosfomycin injection

use alternative or monitor ECG, electrolytes: combo may incr. risk of QT prolongation, cardiac arrhythmias (additive effects)

• foslevodopa
Phenergan (promethazine)

+

foslevodopa

1 interaction

Avoid/Use Alternative

promethazine + foslevodopa

use alternative or monitor BP, respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, hypotension, including orthostasis, syncope; may decr. efficacy of both drugs (additive effects; antagonistic effects)

• fosphenytoin
Phenergan (promethazine)

+

fosphenytoin

1 interaction

Avoid/Use Alternative

promethazine + fosphenytoin

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment; may alter seizure control (additive effects; antagonistic effects, promethazine may decr. seizure threshold)

• frovatriptan
Phenergan (promethazine)

+

frovatriptan

1 interaction

Avoid/Use Alternative

promethazine + frovatriptan

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment (additive effects)

• gabapentin
Phenergan (promethazine)

+

gabapentin

1 interaction

Avoid/Use Alternative

promethazine + gabapentin

use alternative or monitor respiratory rate; consider decreasing dose of one or both drugs: combo may increase risk of profound CNS and respiratory depression, psychomotor impairment; may alter seizure control (additive effects; antagonistic effects, promethazine may decrease seizure threshold)

• gabapentin enacarbil
Phenergan (promethazine)

+

gabapentin enacarbil

1 interaction

Avoid/Use Alternative

promethazine + gabapentin enacarbil

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment (additive effects)

• ganaxolone
Phenergan (promethazine)

+

ganaxolone

1 interaction

Avoid/Use Alternative

promethazine + ganaxolone

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment; may alter seizure control (additive effects; antagonistic effects, promethazine may decr. seizure threshold)

• ginkgo
Phenergan (promethazine)

+

ginkgo

1 interaction

Avoid/Use Alternative

promethazine + ginkgo

avoid consumption of ginkgo seeds; otherwise, caution advised: combo may incr. risk of seizures (additive effects)

• glofitamab
Phenergan (promethazine)

+

glofitamab

1 interaction

Avoid/Use Alternative

promethazine + glofitamab

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment (additive effects)

• glucagon
Phenergan (promethazine)

+

glucagon

1 interaction

Avoid/Use Alternative

promethazine + glucagon

avoid combo if glucagon used as radiologic diagnostic aid: combo may incr. risk of severe constipation, paralytic ileus, other GI adverse effects (additive effects)

• glycopyrrolate
Phenergan (promethazine)

+

glycopyrrolate

1 interaction

Avoid/Use Alternative

promethazine + glycopyrrolate

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, anticholinergic adverse effects (additive effects)

• glycopyrronium topical
Phenergan (promethazine)

+

glycopyrronium topical

1 interaction

Avoid/Use Alternative

promethazine + glycopyrronium topical

avoid combo: combo may incr. risk of anticholinergic adverse effects (additive effects)

• guanfacine
Phenergan (promethazine)

+

guanfacine

1 interaction

Avoid/Use Alternative

promethazine + guanfacine

use alternative or monitor BP, respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, hypotension, including orthostasis (additive effects)

• haloperidol
Phenergan (promethazine)

+

haloperidol

1 interaction

Avoid/Use Alternative

promethazine + haloperidol

avoid combo: combo may incr. risk of QT prolongation, cardiac arrhythmias, hypotension (including orthostasis), CNS and respiratory depression, psychomotor impairment, extrapyramidal symptoms, seizures (additive effects)

• hydrocodone
Phenergan (promethazine)

+

hydrocodone

1 interaction

Avoid/Use Alternative

promethazine + hydrocodone

avoid combo if antitussive use; otherwise use alternative or monitor respiratory rate, BP; decr. (benz)hydrocodone dose by at least 25-50%, consider decr. promethazine dose, use lowest effective doses and shortest duration of concomitant tx: combo may incr. risk of profound CNS and respiratory depression, psychomotor impairment, seizures, severe hypotension (including orthostasis, syncope), severe constipation/paralytic ileus, other anticholinergic adverse effects (additive effects)

• hydromorphone
Phenergan (promethazine)

+

hydromorphone

1 interaction

Avoid/Use Alternative

promethazine + hydromorphone

use alternative or monitor respiratory rate, BP; decr. hydromorphone dose by at least 25-50%, consider decr. promethazine dose, use lowest effective doses and shortest duration of concomitant tx: combo may incr. risk of profound CNS and respiratory depression, psychomotor impairment, seizures, severe hypotension (including orthostasis, syncope), severe constipation, paralytic ileus, urinary retention (additive effects)

• hydroxychloroquine
Phenergan (promethazine)

+

hydroxychloroquine

1 interaction

Avoid/Use Alternative

promethazine + hydroxychloroquine

use alternative or monitor ECG: combo may incr. risk of QT prolongation, cardiac arrhythmias, seizures (additive effects)

• hydroxyzine
Phenergan (promethazine)

+

hydroxyzine

1 interaction

Avoid/Use Alternative

promethazine + hydroxyzine

use alternative or monitor ECG, respiratory rate; decr. dose of one or both drugs: combo may incr. risk of QT prolongation, cardiac arrhythmias, CNS and respiratory depression, psychomotor impairment, anticholinergic adverse effects (additive effects)

• hyoscyamine
Phenergan (promethazine)

+

hyoscyamine

1 interaction

Avoid/Use Alternative

promethazine + hyoscyamine

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, anticholinergic adverse effects (additive effects)

• ifosfamide
Phenergan (promethazine)

+

ifosfamide

1 interaction

Avoid/Use Alternative

promethazine + ifosfamide

use alternative or monitor respiratory rate; decr. promethazine dose; D/C one or both drugs if encephalopathy occurs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, seizures (additive effects)

• iloperidone
Phenergan (promethazine)

+

iloperidone

1 interaction

Avoid/Use Alternative

promethazine + iloperidone

use alternative or monitor respiratory rate, BP; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, extrapyramidal symptoms, hyperthermia, seizures, hypotension, including orthostasis, syncope (additive effects)

• imipramine
Phenergan (promethazine)

+

imipramine

1 interaction

Avoid/Use Alternative

promethazine + imipramine

use alternative or monitor respiratory rate, BP; decr. dose of one or both drugs; caution w/ high environmental temperature: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, seizures, extrapyramidal symptoms, hypotension (including orthostasis), hyperpyrexia, anticholinergic adverse effects (additive effects)

• isocarboxazid
Phenergan (promethazine)

+

isocarboxazid

1 interaction

Avoid/Use Alternative

promethazine + isocarboxazid

use alternative during and x10 days after isocarboxazid use: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, seizures, hypotension (including orthostasis), EPS, severe constipation, paralytic ileus, urinary retention (additive effects)

• isoflurane
Phenergan (promethazine)

+

isoflurane

1 interaction

Avoid/Use Alternative

promethazine + isoflurane

use alternative or monitor ECG, BP, respiratory rate; decr. dose of one or both drugs: combo may incr. risk of QT prolongation, cardiac arrhythmias, hypotension, CNS and respiratory depression, psychomotor impairment (additive effects)

• kava
Phenergan (promethazine)

+

kava

1 interaction

Avoid/Use Alternative

promethazine + kava

avoid combo: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, extrapyramidal symptoms (additive effects)

• ketamine
Phenergan (promethazine)

+

ketamine

1 interaction

Avoid/Use Alternative

promethazine + ketamine

use alternative or monitor respiratory rate; use lowest effective doses and shortest duration of concomitant tx: combo may incr. risk of profound CNS and respiratory depression (including life-threatening), psychomotor impairment, seizures (additive effects)

• kratom
Phenergan (promethazine)

+

kratom

1 interaction

Avoid/Use Alternative

promethazine + kratom

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of profound CNS and respiratory depression, psychomotor impairment, seizures (additive effects)

• lacosamide
Phenergan (promethazine)

+

lacosamide

1 interaction

Avoid/Use Alternative

promethazine + lacosamide

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment; may alter seizure control (additive effects; antagonistic effects, promethazine may decr. seizure threshold)

• lamotrigine
Phenergan (promethazine)

+

lamotrigine

1 interaction

Avoid/Use Alternative

promethazine + lamotrigine

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment; may alter seizure control (additive effects; antagonistic effects, promethazine may decr. seizure threshold)

• lefamulin
Phenergan (promethazine)

+

lefamulin

1 interaction

Avoid/Use Alternative

promethazine + lefamulin

use alternative or monitor ECG: combo may incr. risk of QT prolongation, cardiac arrhythmias (additive effects)

• lemborexant
Phenergan (promethazine)

+

lemborexant

1 interaction

Avoid/Use Alternative

promethazine + lemborexant

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment (additive effects)

• levetiracetam
Phenergan (promethazine)

+

levetiracetam

1 interaction

Avoid/Use Alternative

promethazine + levetiracetam

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment; may alter seizure control (additive effects; antagonistic effects, promethazine may decr. seizure threshold)

• levocetirizine
Phenergan (promethazine)

+

levocetirizine

1 interaction

Avoid/Use Alternative

promethazine + levocetirizine

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment (additive effects)

• levodopa
Phenergan (promethazine)

+

levodopa

1 interaction

Avoid/Use Alternative

promethazine + levodopa

use alternative or monitor BP, respiratory rate; decr. dose of one or both drugs: combo may decr. efficacy of both drugs; may incr. risk of CNS and respiratory depression, psychomotor impairment, hypotension, including orthostasis, syncope (antagonistic effects; additive effects)

• levomilnacipran
Phenergan (promethazine)

+

levomilnacipran

1 interaction

Avoid/Use Alternative

promethazine + levomilnacipran

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, seizures (additive effects)

• levorphanol
Phenergan (promethazine)

+

levorphanol

1 interaction

Avoid/Use Alternative

promethazine + levorphanol

use alternative or monitor respiratory rate, BP; decr. levorphanol start dose by at least 50%, consider decr. promethazine dose, use lowest effective doses and shortest duration of concomitant tx: combo may incr. risk of profound CNS and respiratory depression, psychomotor impairment, severe hypotension (including orthostasis, syncope), seizures, severe constipation, paralytic ileus, urinary retention (additive effects)

• linvoseltamab
Phenergan (promethazine)

+

linvoseltamab

1 interaction

Avoid/Use Alternative

promethazine + linvoseltamab

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment (additive effects)

• lofexidine
Phenergan (promethazine)

+

lofexidine

1 interaction

Avoid/Use Alternative

promethazine + lofexidine

use alternative or monitor ECG, BP, respiratory rate; decr. dose of one or both drugs: combo may incr. risk of QT prolongation, cardiac arrhythmias, CNS and respiratory depression, psychomotor impairment, hypotension, including orthostasis, syncope (additive effects)

• lonafarnib
Phenergan (promethazine)

+

lonafarnib

1 interaction

Avoid/Use Alternative

promethazine + lonafarnib

use alternative or monitor HR, ECG, electrolytes: combo may incr. risk of QT prolongation, cardiac arrhythmias (additive effects)

• lorazepam
Phenergan (promethazine)

+

lorazepam

1 interaction

Avoid/Use Alternative

promethazine + lorazepam

use alternative or monitor respiratory rate; decr. dose of one or both drugs, use lowest effective doses and shortest duration of concomitant tx: combo may incr. risk of profound CNS and respiratory depression, psychomotor impairment; may alter seizure control (additive effects; antagonistic effects, promethazine may decr. seizure threshold)

• loxapine
Phenergan (promethazine)

+

loxapine

1 interaction

Avoid/Use Alternative

promethazine + loxapine

use alternative or monitor respiratory rate, BP; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, seizures, extrapyramidal symptoms, hypotension (including orthostasis, syncope), anticholinergic adverse effects (additive effects)

• lumateperone
Phenergan (promethazine)

+

lumateperone

1 interaction

Avoid/Use Alternative

promethazine + lumateperone

use alternative or monitor respiratory rate, BP; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, seizures, extrapyramidal symptoms, hyperthermia, hypotension, including orthostasis, syncope (additive effects)

• lurasidone
Phenergan (promethazine)

+

lurasidone

1 interaction

Avoid/Use Alternative

promethazine + lurasidone

use alternative or monitor BP, respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, hypotension (including orthostasis, syncope), extrapyramidal symptoms, hyperthermia, seizures (additive effects)

• meclizine
Phenergan (promethazine)

+

meclizine

1 interaction

Avoid/Use Alternative

promethazine + meclizine

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, anticholinergic adverse effects (additive effects)

• melatonin
Phenergan (promethazine)

+

melatonin

1 interaction

Avoid/Use Alternative

promethazine + melatonin

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, seizures (additive effects)

• meperidine
Phenergan (promethazine)

+

meperidine

1 interaction

Avoid/Use Alternative

promethazine + meperidine

use alternative or monitor respiratory rate, BP; decr. meperidine dose 25-50%, consider decr. promethazine dose, use lowest effective doses and shortest duration of concomitant tx: combo may incr. risk of profound CNS and respiratory depression, psychomotor impairment, seizures, severe hypotension (including orthostasis, syncope), severe constipation/paralytic ileus, other anticholinergic adverse effects (additive effects)

• meprobamate
Phenergan (promethazine)

+

meprobamate

1 interaction

Avoid/Use Alternative

promethazine + meprobamate

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment (additive effects)

• metaxalone
Phenergan (promethazine)

+

metaxalone

1 interaction

Avoid/Use Alternative

promethazine + metaxalone

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment (additive effects)

• methadone
Phenergan (promethazine)

+

methadone

1 interaction

Avoid/Use Alternative

promethazine + methadone

use alternative or monitor respiratory rate, BP, ECG; decr. methadone dose by at least 25-50%, consider decr. promethazine dose, use lowest effective doses and shortest duration of concomitant tx: combo may incr. risk of profound CNS and respiratory depression, psychomotor impairment, seizures, QT prolongation, cardiac arrhythmias, severe hypotension (including orthostasis, syncope), severe constipation/paralytic ileus, other anticholinergic adverse effects (additive effects)

• methocarbamol
Phenergan (promethazine)

+

methocarbamol

1 interaction

Avoid/Use Alternative

promethazine + methocarbamol

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, seizures (additive effects)

• methohexital
Phenergan (promethazine)

+

methohexital

1 interaction

Avoid/Use Alternative

promethazine + methohexital

use alternative or monitor respiratory rate, BP; decr. methohexital by at least 50%, consider decr. promethazine dose: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, hypotension (additive effects)

• methsuximide
Phenergan (promethazine)

+

methsuximide

1 interaction

Avoid/Use Alternative

promethazine + methsuximide

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment; may alter seizure control (additive effects; antagonistic effects, promethazine may decr. seizure threshold)

• methyldopa
Phenergan (promethazine)

+

methyldopa

1 interaction

Avoid/Use Alternative

promethazine + methyldopa

use alternative or monitor respiratory rate, BP; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, hypotension, including orthostasis (additive effects)

• metoclopramide
Phenergan (promethazine)

+

metoclopramide

1 interaction

Avoid/Use Alternative

promethazine + metoclopramide

avoid combo: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, extrapyramidal symptoms, seizures; may decr. metoclopramide efficacy (additive effects; antagonistic effects; absorption of oral metoclopramide affected by delayed gastric emptying)

• metyrapone
Phenergan (promethazine)

+

metyrapone

1 interaction

Avoid/Use Alternative

promethazine + metyrapone

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment (additive effects)

• metyrosine
Phenergan (promethazine)

+

metyrosine

1 interaction

Avoid/Use Alternative

promethazine + metyrosine

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, extrapyramidal symptoms (additive effects)

• midazolam
Phenergan (promethazine)

+

midazolam

1 interaction

Avoid/Use Alternative

promethazine + midazolam

use alternative or monitor respiratory rate, BP; decr. dose of one or both drugs, use lowest effective doses and shortest duration of concomitant tx: combo may incr. risk of profound CNS and respiratory depression, psychomotor impairment, hypotension; may alter seizure control (additive effects; antagonistic effects, promethazine may decr. seizure threshold)

• milnacipran
Phenergan (promethazine)

+

milnacipran

1 interaction

Avoid/Use Alternative

promethazine + milnacipran

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, seizures (additive effects)

• milsaperidone
Phenergan (promethazine)

+

milsaperidone

1 interaction

Avoid/Use Alternative

promethazine + milsaperidone

use alternative or monitor BP, respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS depression, psychomotor impairment, seizures, extrapyramidal symptoms, hyperthermia, hypotension, including orthostasis, syncope (additive effects)

• mirtazapine
Phenergan (promethazine)

+

mirtazapine

1 interaction

Avoid/Use Alternative

promethazine + mirtazapine

use alternative or monitor respiratory rate, BP; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, seizures, anticholinergic adverse effects, hypotension, including orthostasis (additive effects)

• mitotane
Phenergan (promethazine)

+

mitotane

1 interaction

Avoid/Use Alternative

promethazine + mitotane

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment (additive effects)

• mobocertinib
Phenergan (promethazine)

+

mobocertinib

1 interaction

Avoid/Use Alternative

promethazine + mobocertinib

use alternative or monitor ECG, electrolytes: combo may incr. risk of QT prolongation, cardiac arrhythmias (additive effects)

• molindone
Phenergan (promethazine)

+

molindone

1 interaction

Avoid/Use Alternative

promethazine + molindone

use alternative or monitor respiratory rate, BP; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, hypotension (including orthostasis), anticholinergic adverse effects, seizures, extrapyramidal symptoms (additive effects)

• morphine
Phenergan (promethazine)

+

morphine

1 interaction

Avoid/Use Alternative

promethazine + morphine

use alternative or monitor respiratory rate, BP; decr. morphine dose by at least 25-50%, consider decr. promethazine dose, use lowest effective doses and shortest duration of concomitant tx: combo may incr. risk of profound CNS and respiratory depression, psychomotor impairment, severe hypotension (including orthostasis, syncope), seizures, severe constipation/paralytic ileus, other anticholinergic adverse effects (additive effects)

• mosunetuzumab
Phenergan (promethazine)

+

mosunetuzumab

1 interaction

Avoid/Use Alternative

promethazine + mosunetuzumab

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS depression, psychomotor impairment (additive effects)

• mycophenolate mofetil
Phenergan (promethazine)

+

mycophenolate mofetil

1 interaction

Avoid/Use Alternative

promethazine + mycophenolate mofetil

use alternative or monitor respiratory rate; decr. promethazine dose: combo may incr. risk of CNS and respiratory depression, psychomotor impairment (additive effects)

• nalbuphine
Phenergan (promethazine)

+

nalbuphine

1 interaction

Avoid/Use Alternative

promethazine + nalbuphine

use alternative or monitor respiratory rate, BP; decr. nalbuphine dose by at least 25-50%, consider decr. promethazine dose, use lowest effective doses and shortest duration of concomitant tx: combo may incr. risk of profound CNS and respiratory depression, psychomotor impairment, severe hypotension (including orthostasis, syncope), seizures, severe constipation/paralytic ileus, other anticholinergic adverse effects (additive effects)

• naltrexone
Phenergan (promethazine)

+

naltrexone

1 interaction

Avoid/Use Alternative

promethazine + naltrexone

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment (additive effects)

• naratriptan
Phenergan (promethazine)

+

naratriptan

1 interaction

Avoid/Use Alternative

promethazine + naratriptan

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment (additive effects)

• nefazodone
Phenergan (promethazine)

+

nefazodone

1 interaction

Avoid/Use Alternative

promethazine + nefazodone

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, seizures (additive effects)

• nelarabine
Phenergan (promethazine)

+

nelarabine

1 interaction

Avoid/Use Alternative

promethazine + nelarabine

use alternative or monitor respiratory rate; decr. promethazine dose; withhold nelarabine if Grade 2 or greater somnolence occurs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, seizures (additive effects)

• nortriptyline
Phenergan (promethazine)

+

nortriptyline

1 interaction

Avoid/Use Alternative

promethazine + nortriptyline

use alternative or monitor respiratory rate, BP; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, seizures, extrapyramidal symptoms, hypotension (including orthostasis), anticholinergic adverse effects (additive effects)

• olanzapine
Phenergan (promethazine)

+

olanzapine

1 interaction

Avoid/Use Alternative

promethazine + olanzapine

use alternative or monitor respiratory rate, BP; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, seizures, hypotension (including orthostasis, syncope), extrapyramidal symptoms, life-threatening anticholinergic adverse effects, including constipation, paralytic ileus, hyperthermia (additive effects)

• oliceridine
Phenergan (promethazine)

+

oliceridine

1 interaction

Avoid/Use Alternative

promethazine + oliceridine

use alternative or monitor respiratory rate, ECG, BP; decr. oliceridine by at least 25-50%, consider decr. promethazine dose, use lowest effective doses and shortest duration of concomitant tx: combo may incr. risk of profound CNS and respiratory depression, psychomotor impairment, QT prolongation, cardiac arrhythmias, severe hypotension (including orthostasis, syncope), seizures, severe constipation/paralytic ileus, other anticholinergic adverse effects (additive effects)

• opicapone
Phenergan (promethazine)

+

opicapone

1 interaction

Avoid/Use Alternative

promethazine + opicapone

use alternative or monitor respiratory rate, BP; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, hypotension, including orthostasis, syncope (additive effects)

• opium
Phenergan (promethazine)

+

opium

1 interaction

Avoid/Use Alternative

promethazine + opium

use alternative or monitor respiratory rate, BP; decr. dose of one or both drugs, use lowest effective doses and shortest duration of concomitant tx: combo may incr. risk of profound CNS and respiratory depression, psychomotor impairment, severe hypotension, including orthostasis, syncope (additive effects)

• orphenadrine
Phenergan (promethazine)

+

orphenadrine

1 interaction

Avoid/Use Alternative

promethazine + orphenadrine

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, anticholinergic adverse effects (additive effects)

• oxazepam
Phenergan (promethazine)

+

oxazepam

1 interaction

Avoid/Use Alternative

promethazine + oxazepam

use alternative or monitor respiratory rate, BP; use lowest effective doses and shortest duration of concomitant tx: combo may incr. risk of profound CNS and respiratory depression, psychomotor impairment, hypotension (additive effects)

• oxcarbazepine
Phenergan (promethazine)

+

oxcarbazepine

1 interaction

Avoid/Use Alternative

promethazine + oxcarbazepine

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment; may alter seizure control (additive effects; antagonistic effects, promethazine may decr. seizure threshold)

• oxybate
Phenergan (promethazine)

+

oxybate

1 interaction

Avoid/Use Alternative

promethazine + oxybate

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of profound CNS and respiratory depression, psychomotor impairment, hypotension, syncope (additive effects)

• oxybutynin
Phenergan (promethazine)

+

oxybutynin

1 interaction

Avoid/Use Alternative

promethazine + oxybutynin

use alternative or monitor respiratory rate; decr. dose of one or both drugs or consider oxybutynin transdermal patch: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, anticholinergic adverse effects; somnolence less likely with oxybutynin transdermal patch; may decr. promethazine efficacy (additive effects; antagonistic effects)

• oxycodone
Phenergan (promethazine)

+

oxycodone

1 interaction

Avoid/Use Alternative

promethazine + oxycodone

use alternative or monitor respiratory rate, BP; decr. oxycodone start dose by at least 50%, consider decr. promethazine dose, use lowest effective doses and shortest duration of concomitant tx: combo may incr. risk of profound CNS and respiratory depression, psychomotor impairment, seizures, severe hypotension (including orthostasis, syncope), severe constipation/paralytic ileus, other anticholinergic adverse effects (additive effects)

• oxymorphone
Phenergan (promethazine)

+

oxymorphone

1 interaction

Avoid/Use Alternative

promethazine + oxymorphone

use alternative or monitor respiratory rate, BP; decr. oxymorphone start dose by at least 50%, consider decr. promethazine dose, use lowest effective doses and shortest duration of concomitant tx: combo may incr. risk of profound CNS and respiratory depression, psychomotor impairment, seizures, severe hypotension (including orthostasis, syncope), severe constipation, paralytic ileus, urinary retention (additive effects)

• paliperidone
Phenergan (promethazine)

+

paliperidone

1 interaction

Avoid/Use Alternative

promethazine + paliperidone

use alternative or monitor ECG, BP, respiratory rate; decr. dose of one or both drugs, use lowest effective doses and shortest duration of concomitant tx: combo may incr. risk of QT prolongation, cardiac arrhythmias, CNS and respiratory depression, psychomotor impairment, seizures, extrapyramidal symptoms, hyperthermia, hypotension, including orthostasis, syncope (additive effects)

• paroxetine
Phenergan (promethazine)

+

paroxetine

1 interaction

Avoid/Use Alternative

promethazine + paroxetine

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, seizures (additive effects)

• passion flower
Phenergan (promethazine)

+

passion flower

1 interaction

Avoid/Use Alternative

promethazine + passion flower

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment (additive effects)

• pentazocine
Phenergan (promethazine)

+

pentazocine

1 interaction

Avoid/Use Alternative

promethazine + pentazocine

use alternative or monitor respiratory rate, BP; decr. pentazocine dose by at least 25-50%, consider decr. promethazine dose, use lowest effective doses and shortest duration of concomitant tx: combo may incr. risk of profound CNS and respiratory depression, psychomotor impairment, severe hypotension (including orthostasis, syncope), seizures, anticholinergic adverse effects (additive effects)

• pentobarbital
Phenergan (promethazine)

+

pentobarbital

1 interaction

Avoid/Use Alternative

promethazine + pentobarbital

use alternative or monitor respiratory rate, BP; decr. pentobarbital by at least 50%, consider decr. promethazine dose: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, hypotension (additive effects)

• perampanel
Phenergan (promethazine)

+

perampanel

1 interaction

Avoid/Use Alternative

promethazine + perampanel

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment; may alter seizure control (additive effects; antagonistic effects, promethazine may decr. seizure threshold)

• perphenazine
Phenergan (promethazine)

+

perphenazine

1 interaction

Avoid/Use Alternative

promethazine + perphenazine

use alternative or monitor respiratory rate, BP; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, seizures, extrapyramidal symptoms, severe hypotension (including orthostasis, syncope), anticholinergic adverse effects (additive effects, duplicate therapy)

• phenelzine
Phenergan (promethazine)

+

phenelzine

1 interaction

Avoid/Use Alternative

promethazine + phenelzine

use alternative or monitor respiratory rate, BP; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, seizures, hypotension (including orthostasis), EPS, severe constipation, paralytic ileus, urinary retention (additive effects; mechanism unknown)

• pheniramine
Phenergan (promethazine)

+

pheniramine

1 interaction

Avoid/Use Alternative

promethazine + pheniramine

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, anticholinergic adverse effects (additive effects)

• phenobarbital
Phenergan (promethazine)

+

phenobarbital

1 interaction

Avoid/Use Alternative

promethazine + phenobarbital

use alternative or monitor respiratory rate, BP; decr. phenobarbital by at least 50%, consider decr. promethazine dose: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, hypotension, including orthostasis; may alter seizure control (additive effects; antagonistic effects, promethazine may decr. seizure threshold)

• phenytoin
Phenergan (promethazine)

+

phenytoin

1 interaction

Avoid/Use Alternative

promethazine + phenytoin

use alternative or monitor phenytoin levels, respiratory rate; decr. promethazine dose: combo may incr. phenytoin levels, risk of toxicity; may incr. risk of CNS and respiratory depression, psychomotor impairment; may alter seizure control (mechanism unknown; additive effects; antagonistic effects, promethazine may decr. seizure threshold)

• pitolisant
Phenergan (promethazine)

+

pitolisant

1 interaction

Avoid/Use Alternative

promethazine + pitolisant

avoid combo: combo may decr. efficacy of both drugs (antagonistic effects)

• porfimer
Phenergan (promethazine)

+

porfimer

1 interaction

Avoid/Use Alternative

promethazine + porfimer

avoid combo: combo may incr. risk of photosensitivity reaction (additive effects)

• pramipexole
Phenergan (promethazine)

+

pramipexole

1 interaction

Avoid/Use Alternative

promethazine + pramipexole

use alternative: combo may decr. pramipexole efficacy; may incr. risk of CNS and respiratory depression, psychomotor impairment, hypotension, including orthostasis, syncope (antagonistic effects; additive effects)

• pramlintide
Phenergan (promethazine)

+

pramlintide

1 interaction

Avoid/Use Alternative

promethazine + pramlintide

consider alternative: combo may incr. risk of severe constipation, paralytic ileus (additive effects)

• pregabalin
Phenergan (promethazine)

+

pregabalin

1 interaction

Avoid/Use Alternative

promethazine + pregabalin

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of profound CNS and respiratory depression, psychomotor impairment; may alter seizure control (additive effects; antagonistic effects, promethazine may decr. seizure threshold)

• primidone
Phenergan (promethazine)

+

primidone

1 interaction

Avoid/Use Alternative

promethazine + primidone

use alternative or monitor respiratory rate; decr. primidone by at least 50%, consider decr. promethazine dose: combo may incr. risk of CNS and respiratory depression, psychomotor impairment; may alter seizure control (additive effects; antagonistic effects, promethazine may decr. seizure threshold)

• procarbazine
Phenergan (promethazine)

+

procarbazine

1 interaction

Avoid/Use Alternative

promethazine + procarbazine

use alternative or monitor respiratory rate, BP; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, seizures, hypotension (additive effects)

• prochlorperazine
Phenergan (promethazine)

+

prochlorperazine

1 interaction

Avoid/Use Alternative

promethazine + prochlorperazine

use alternative or monitor BP, respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, seizures, hypotension (including orthostasis), extrapyramidal symptoms, anticholinergic adverse effects (additive effects; duplicate therapy)

• propofol
Phenergan (promethazine)

+

propofol

1 interaction

Avoid/Use Alternative

promethazine + propofol

use alternative or monitor respiratory rate, BP; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, seizures, severe hypotension (additive effects)

• protriptyline
Phenergan (promethazine)

+

protriptyline

1 interaction

Avoid/Use Alternative

promethazine + protriptyline

use alternative or monitor respiratory rate, BP; decr. dose of one or both drugs; caution w/ high environmental temperature: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, seizures, extrapyramidal symptoms, hypotension (including orthostasis), hyperpyrexia, anticholinergic adverse effects (additive effects)

• pyrilamine
Phenergan (promethazine)

+

pyrilamine

1 interaction

Avoid/Use Alternative

promethazine + pyrilamine

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, anticholinergic adverse effects (additive effects)

• quazepam
Phenergan (promethazine)

+

quazepam

1 interaction

Avoid/Use Alternative

promethazine + quazepam

use alternative or monitor respiratory rate; decr. dose of one or both drugs, use lowest effective doses and shortest duration of concomitant tx: combo may incr. risk of CNS and respiratory depression, psychomotor impairment (additive effects)

• quetiapine
Phenergan (promethazine)

+

quetiapine

1 interaction

Avoid/Use Alternative

promethazine + quetiapine

use alternative or monitor BP, respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, seizures, extrapyramidal symptoms, hypotension (including orthostasis, syncope), anticholinergic adverse effects (additive effects)

• quizartinib
Phenergan (promethazine)

+

quizartinib

1 interaction

Avoid/Use Alternative

promethazine + quizartinib

use alternative or monitor ECG, electrolytes: combo may incr. risk of QT prolongation, cardiac arrhythmias (additive effects)

• ramelteon
Phenergan (promethazine)

+

ramelteon

1 interaction

Avoid/Use Alternative

promethazine + ramelteon

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment (additive effects)

• rasagiline
Phenergan (promethazine)

+

rasagiline

1 interaction

Avoid/Use Alternative

promethazine + rasagiline

use alternative or monitor respiratory rate, BP; decr. dose of one or both drugs: combo may decr. rasagiline efficacy; may incr. risk of CNS and respiratory depression, psychomotor impairment, hypotension, including orthostasis (antagonistic effects; additive effects)

• remifentanil
Phenergan (promethazine)

+

remifentanil

1 interaction

Avoid/Use Alternative

promethazine + remifentanil

use alternative or monitor respiratory rate, BP; decr. remifentanil dose by at least 25-50%, consider decr. promethazine dose, use lowest effective doses and shortest duration of concomitant tx: combo may incr. risk of profound CNS and respiratory depression, psychomotor impairment, seizures, severe hypotension (including orthostasis, syncope), severe constipation/paralytic ileus, other anticholinergic adverse effects (additive effects)

• remimazolam
Phenergan (promethazine)

+

remimazolam

1 interaction

Avoid/Use Alternative

promethazine + remimazolam

use alternative or monitor BP, respiratory rate; use lowest effective doses and shortest duration of concomitant tx: combo may incr. risk of hypotension, profound CNS and respiratory depression, psychomotor impairment (additive effects)

• repotrectinib
Phenergan (promethazine)

+

repotrectinib

1 interaction

Avoid/Use Alternative

promethazine + repotrectinib

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment (additive effects)

• revefenacin inhaled
Phenergan (promethazine)

+

revefenacin inhaled

1 interaction

Avoid/Use Alternative

promethazine + revefenacin inhaled

avoid combo: combo may incr. anticholinergic adverse effects (additive effects)

• risperidone
Phenergan (promethazine)

+

risperidone

1 interaction

Avoid/Use Alternative

promethazine + risperidone

use alternative or monitor respiratory rate, BP; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, extrapyramidal symptoms, hyperthermia, seizures, hypotension, including orthostasis, syncope (additive effects)

• rivastigmine
Phenergan (promethazine)

+

rivastigmine

1 interaction

Avoid/Use Alternative

promethazine + rivastigmine

use alternative: combo may increase risk of seizures, extrapyramidal symptoms; may decrease efficacy of both drugs (additive effects; antagonistic effects)

• rizatriptan
Phenergan (promethazine)

+

rizatriptan

1 interaction

Avoid/Use Alternative

promethazine + rizatriptan

use alternative or monitor respiratory rate, decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment (additive effects)

• ropeginterferon alfa-2b
Phenergan (promethazine)

+

ropeginterferon alfa-2b

1 interaction

Avoid/Use Alternative

promethazine + ropeginterferon alfa-2b

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment (additive effects)

• ropinirole
Phenergan (promethazine)

+

ropinirole

1 interaction

Avoid/Use Alternative

promethazine + ropinirole

use alternative or monitor BP, respiratory rate; decr. dose of one or both drugs: combo may decr. ropinirole efficacy; may incr. risk of CNS and respiratory depression, psychomotor impairment, hypotension, including orthostasis, syncope (antagonistic effects; additive effects)

• rotigotine transdermal
Phenergan (promethazine)

+

rotigotine transdermal

1 interaction

Avoid/Use Alternative

promethazine + rotigotine transdermal

use alternative: combo may decr. rotigotine efficacy; may incr. risk of CNS and respiratory depression, psychomotor impairment, severe hypotension, including orthostasis, syncope (antagonistic effects; additive effects)

• rufinamide
Phenergan (promethazine)

+

rufinamide

1 interaction

Avoid/Use Alternative

promethazine + rufinamide

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment; may alter seizure control (additive effects; antagonistic effects, promethazine may decr. seizure threshold)

• safinamide
Phenergan (promethazine)

+

safinamide

1 interaction

Avoid/Use Alternative

promethazine + safinamide

use alternative or monitor respiratory rate, BP; decr. dose of one or both drugs: combo may decr. safinamide efficacy; may incr. risk of CNS and respiratory depression, psychomotor impairment, hypotension (including orthostasis), EPS (antagonistic effects; additive effects; mechanism unknown)

• scopolamine
Phenergan (promethazine)

+

scopolamine

1 interaction

Avoid/Use Alternative

promethazine + scopolamine

use alternative or monitor respiratory rate; decrease dose of one or both drugs: combo may increase risk of CNS and respiratory depression, psychomotor impairment, seizures, anticholinergic adverse effects (additive effects)

• selegiline
Phenergan (promethazine)

+

selegiline

1 interaction

Avoid/Use Alternative

promethazine + selegiline

use alternative or monitor respiratory rate, BP; decr. dose of one or both drugs: combo may decr. selegiline efficacy; may incr. risk of CNS and respiratory depression, psychomotor impairment, hypotension, including orthostasis (antagonistic effects; additive effects)

• selegiline transdermal
Phenergan (promethazine)

+

selegiline transdermal

1 interaction

Avoid/Use Alternative

promethazine + selegiline transdermal

use alternative or monitor respiratory rate, BP; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, seizures, hypotension (including orthostasis), EPS (additive effects; mechanism unknown)

• selinexor
Phenergan (promethazine)

+

selinexor

1 interaction

Avoid/Use Alternative

promethazine + selinexor

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment (additive effects)

• sertraline
Phenergan (promethazine)

+

sertraline

1 interaction

Avoid/Use Alternative

promethazine + sertraline

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, seizures (additive effects)

• sevoflurane
Phenergan (promethazine)

+

sevoflurane

1 interaction

Avoid/Use Alternative

promethazine + sevoflurane

use alternative or monitor ECG, BP, respiratory rate; decr. dose of one or both drugs: combo may incr. risk of QT prolongation, cardiac arrhythmias, hypotension, CNS and respiratory depression, psychomotor impairment, seizures (additive effects)

• sofpironium topical
Phenergan (promethazine)

+

sofpironium topical

1 interaction

Avoid/Use Alternative

promethazine + sofpironium topical

avoid combo: combo may incr. risk of anticholinergic adverse effects (additive effects)

• solifenacin
Phenergan (promethazine)

+

solifenacin

1 interaction

Avoid/Use Alternative

promethazine + solifenacin

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, anticholinergic adverse effects (additive effects)

• sotalol
Phenergan (promethazine)

+

sotalol

1 interaction

Avoid/Use Alternative

promethazine + sotalol

use alternative or monitor ECG, BP: combo may incr. risk of QT prolongation, cardiac arrhythmias, hypotension (additive effects)

• stiripentol
Phenergan (promethazine)

+

stiripentol

1 interaction

Avoid/Use Alternative

promethazine + stiripentol

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment; may alter seizure control (additive effects; antagonistic effects, promethazine may decr. seizure threshold)

• sufentanil
Phenergan (promethazine)

+

sufentanil

1 interaction

Avoid/Use Alternative

promethazine + sufentanil

use alternative or monitor respiratory rate, BP; decr. sufentanil dose by at least 25-50%, consider decr. promethazine dose, use lowest effective doses: combo may incr. risk of profound CNS and respiratory depression, psychomotor impairment, severe hypotension (including orthostasis, syncope), seizures, severe constipation/paralytic ileus, other anticholinergic adverse effects (additive effects)

• sumatriptan
Phenergan (promethazine)

+

sumatriptan

1 interaction

Avoid/Use Alternative

promethazine + sumatriptan

use alternative or monitor respiratory rate, decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, seizures (additive effects)

• suvorexant
Phenergan (promethazine)

+

suvorexant

1 interaction

Avoid/Use Alternative

promethazine + suvorexant

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment (additive effects)

• tapentadol
Phenergan (promethazine)

+

tapentadol

1 interaction

Avoid/Use Alternative

promethazine + tapentadol

use alternative or monitor respiratory rate, BP; decrease tapentadol dose by at least 25-50%, consider decreasing promethazine dose, use lowest effective doses and shortest duration of concomitant treatment: combo may increase risk of profound CNS and respiratory depression, psychomotor impairment, severe hypotension (including orthostasis, syncope), severe constipation, paralytic ileus, urinary retention (additive effects)

• tasimelteon
Phenergan (promethazine)

+

tasimelteon

1 interaction

Avoid/Use Alternative

promethazine + tasimelteon

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment (additive effects)

• temazepam
Phenergan (promethazine)

+

temazepam

1 interaction

Avoid/Use Alternative

promethazine + temazepam

use alternative or monitor respiratory rate; decr. dose of one or both drugs, use lowest effective doses and shortest duration of concomitant tx: combo may incr. risk of profound CNS and respiratory depression, psychomotor impairment (additive effects)

• tetrabenazine
Phenergan (promethazine)

+

tetrabenazine

1 interaction

Avoid/Use Alternative

promethazine + tetrabenazine

use alternative or monitor ECG, respiratory rate; decr. dose of one or both drugs: combo may incr. risk of QT prolongation, cardiac arrhythmias, CNS and respiratory depression, psychomotor impairment, extrapyramidal symptoms (additive effects)

• thalidomide
Phenergan (promethazine)

+

thalidomide

1 interaction

Avoid/Use Alternative

promethazine + thalidomide

use alternative or monitor respiratory rate, BP; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, seizures, hypotension, including orthostasis (additive effects)

• thiotepa
Phenergan (promethazine)

+

thiotepa

1 interaction

Avoid/Use Alternative

promethazine + thiotepa

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, seizures (additive effects)

• thiothixene
Phenergan (promethazine)

+

thiothixene

1 interaction

Avoid/Use Alternative

promethazine + thiothixene

use alternative or monitor respiratory rate, BP; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, seizures, extrapyramidal symptoms, hypotension (including syncope), anticholinergic adverse effects (additive effects)

• tiagabine
Phenergan (promethazine)

+

tiagabine

1 interaction

Avoid/Use Alternative

promethazine + tiagabine

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment; may alter seizure control (additive effects; antagonistic effects, promethazine may decr. seizure threshold)

• tizanidine
Phenergan (promethazine)

+

tizanidine

1 interaction

Avoid/Use Alternative

promethazine + tizanidine

use alternative or monitor BP, respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, hypotension, including orthostasis, syncope (additive effects)

• tolcapone
Phenergan (promethazine)

+

tolcapone

1 interaction

Avoid/Use Alternative

promethazine + tolcapone

use alternative or monitor respiratory rate, BP; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, hypotension, including orthostasis, syncope (additive effects)

• tolterodine
Phenergan (promethazine)

+

tolterodine

1 interaction

Avoid/Use Alternative

promethazine + tolterodine

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, anticholinergic adverse effects; may decr. phenothiazine efficacy (additive effects; antagonistic effects)

• topiramate
Phenergan (promethazine)

+

topiramate

1 interaction

Avoid/Use Alternative

promethazine + topiramate

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, hyperthermia; may alter seizure control (additive effects; antagonistic effects, promethazine may decr. seizure threshold)

• toremifene
Phenergan (promethazine)

+

toremifene

1 interaction

Avoid/Use Alternative

promethazine + toremifene

use alternative or monitor ECG: combo may incr. risk of QT prolongation, cardiac arrhythmias (additive effects)

• tradipitant
Phenergan (promethazine)

+

tradipitant

1 interaction

Avoid/Use Alternative

promethazine + tradipitant

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment (additive effects)

• tramadol
Phenergan (promethazine)

+

tramadol

1 interaction

Avoid/Use Alternative

promethazine + tramadol

use alternative or monitor respiratory rate, ECG, BP; decr. tramadol by at least 25-50%, consider decr. promethazine dose, use lowest effective doses and shortest duration of concomitant tx: combo may incr. risk of profound CNS and respiratory depression, psychomotor impairment, seizures, QT prolongation, cardiac arrhythmias, severe hypotension (including orthostasis, syncope), severe constipation, paralytic ileus, urinary retention (additive effects)

• tranylcypromine
Phenergan (promethazine)

+

tranylcypromine

1 interaction

Avoid/Use Alternative

promethazine + tranylcypromine

use alternative or monitor BP; consider decr. dose of one or both drugs: combo may incr. risk of CNS depression, psychomotor impairment, EPS, hypotension (including orthostasis), severe constipation, paralytic ileus, urinary retention (additive effects)

• trazodone
Phenergan (promethazine)

+

trazodone

1 interaction

Avoid/Use Alternative

promethazine + trazodone

use alternative or monitor respiratory rate, BP; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, hypotension, including orthostasis, syncope (additive effects)

• tretinoin topical
Phenergan (promethazine)

+

tretinoin topical

1 interaction

Avoid/Use Alternative

promethazine + tretinoin topical

consider alternative, especially if tretinoin topical cosmetic use: combo may incr. risk of phototoxicity or augment phototoxic reaction (possible additive effects)

• triazolam
Phenergan (promethazine)

+

triazolam

1 interaction

Avoid/Use Alternative

promethazine + triazolam

use alternative or monitor respiratory rate; decr. dose of one or both drugs, use lowest effective doses and shortest duration of concomitant tx: combo may incr. risk of profound CNS and respiratory depression, psychomotor impairment (additive effects)

• trifluoperazine
Phenergan (promethazine)

+

trifluoperazine

1 interaction

Avoid/Use Alternative

promethazine + trifluoperazine

use alternative or monitor respiratory rate, BP; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, seizures, extrapyramidal symptoms, severe hypotension (including orthostasis), anticholinergic adverse effects (additive effects, duplicate therapy)

• trihexyphenidyl
Phenergan (promethazine)

+

trihexyphenidyl

1 interaction

Avoid/Use Alternative

promethazine + trihexyphenidyl

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, hyperthermia, anticholinergic adverse effects; may decr. phenothiazine efficacy (additive effects; antagonistic effects)

• trimethobenzamide
Phenergan (promethazine)

+

trimethobenzamide

1 interaction

Avoid/Use Alternative

promethazine + trimethobenzamide

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, extrapyramidal symptoms (additive effects)

• trimipramine
Phenergan (promethazine)

+

trimipramine

1 interaction

Avoid/Use Alternative

promethazine + trimipramine

use alternative or monitor respiratory rate, BP; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, seizures, extrapyramidal symptoms, hypotension (including orthostasis), anticholinergic adverse effects (additive effects)

• triprolidine
Phenergan (promethazine)

+

triprolidine

1 interaction

Avoid/Use Alternative

promethazine + triprolidine

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, anticholinergic adverse effects (additive effects)

• trospium
Phenergan (promethazine)

+

trospium

1 interaction

Avoid/Use Alternative

promethazine + trospium

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, anticholinergic adverse effects; may decr. phenothiazine efficacy (additive effects; antagonistic effects)

• valbenazine
Phenergan (promethazine)

+

valbenazine

1 interaction

Avoid/Use Alternative

promethazine + valbenazine

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment (additive effects)

• valerian
Phenergan (promethazine)

+

valerian

1 interaction

Avoid/Use Alternative

promethazine + valerian

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment (additive effects)

• valproic acid
Phenergan (promethazine)

+

valproic acid

1 interaction

Avoid/Use Alternative

promethazine + valproic acid

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment; may alter seizure control (additive effects; antagonistic effects, promethazine may decr. seizure threshold)

• vandetanib
Phenergan (promethazine)

+

vandetanib

1 interaction

Avoid/Use Alternative

promethazine + vandetanib

use alternative or monitor ECG, electrolytes: combo may incr. risk of QT prolongation, cardiac arrhythmias (additive effects)

• venlafaxine
Phenergan (promethazine)

+

venlafaxine

1 interaction

Avoid/Use Alternative

promethazine + venlafaxine

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, seizures (additive effects)

• vigabatrin
Phenergan (promethazine)

+

vigabatrin

1 interaction

Avoid/Use Alternative

promethazine + vigabatrin

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment; may alter seizure control (additive effects; antagonistic effects, promethazine may decr. seizure threshold)

• vilazodone
Phenergan (promethazine)

+

vilazodone

1 interaction

Avoid/Use Alternative

promethazine + vilazodone

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, seizures (additive effects)

• viloxazine
Phenergan (promethazine)

+

viloxazine

1 interaction

Avoid/Use Alternative

promethazine + viloxazine

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment (additive effects)

• zaleplon
Phenergan (promethazine)

+

zaleplon

1 interaction

Avoid/Use Alternative

promethazine + zaleplon

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment (additive effects)

• ziconotide
Phenergan (promethazine)

+

ziconotide

1 interaction

Avoid/Use Alternative

promethazine + ziconotide

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment (additive effects)

• ziprasidone
Phenergan (promethazine)

+

ziprasidone

1 interaction

Avoid/Use Alternative

promethazine + ziprasidone

use alternative or monitor ECG, BP, respiratory rate; decr. dose of one or both drugs: combo may incr. risk of QT prolongation, cardiac arrhythmias, hypotension (including orthostasis, syncope), CNS and respiratory depression, psychomotor impairment, seizures, extrapyramidal symptoms, hyperthermia (additive effects)

• zolmitriptan
Phenergan (promethazine)

+

zolmitriptan

1 interaction

Avoid/Use Alternative

promethazine + zolmitriptan

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment (additive effects)

• zolpidem
Phenergan (promethazine)

+

zolpidem

1 interaction

Avoid/Use Alternative

promethazine + zolpidem

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment (additive effects)

• zonisamide
Phenergan (promethazine)

+

zonisamide

1 interaction

Avoid/Use Alternative

promethazine + zonisamide

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment, hyperthermia; may alter seizure control (additive effects; antagonistic effects, promethazine may decr. seizure threshold)

• zuranolone
Phenergan (promethazine)

+

zuranolone

1 interaction

Avoid/Use Alternative

promethazine + zuranolone

use alternative or monitor respiratory rate; decr. dose of one or both drugs: combo may incr. risk of CNS and respiratory depression, psychomotor impairment (additive effects)

Monitor/Modify Tx

• acebutolol
Phenergan (promethazine)

+

acebutolol

1 interaction

Monitor/Modify Tx

promethazine + acebutolol

monitor BP: combo may incr. risk of hypotension (additive effects)

• adagrasib
Phenergan (promethazine)

+

adagrasib

1 interaction

Monitor/Modify Tx

promethazine + adagrasib

monitor ECG, electrolytes: combo may incr. risk of QT prolongation, cardiac arrhythmias (additive effects)

• alfuzosin
Phenergan (promethazine)

+

alfuzosin

1 interaction

Monitor/Modify Tx

promethazine + alfuzosin

monitor BP: combo may incr. risk of hypotension, including orthostasis, syncope (additive effects)

• aliskiren
Phenergan (promethazine)

+

aliskiren

1 interaction

Monitor/Modify Tx

promethazine + aliskiren

monitor BP: combo may incr. risk of hypotension (additive effects)

• alprostadil intracavernous
Phenergan (promethazine)

+

alprostadil intracavernous

1 interaction

Monitor/Modify Tx

promethazine + alprostadil intracavernous

monitor BP: combo may increase risk of hypotension (additive effects)

• amifostine
Phenergan (promethazine)

+

amifostine

1 interaction

Monitor/Modify Tx

promethazine + amifostine

monitor BP: combo may incr. risk of severe hypotension, including syncope (additive effects)

• amiloride
Phenergan (promethazine)

+

amiloride

1 interaction

Monitor/Modify Tx

promethazine + amiloride

monitor BP: combo may incr. risk of hypotension (additive effects)

• amiodarone
Phenergan (promethazine)

+

amiodarone

1 interaction

Monitor/Modify Tx

promethazine + amiodarone

monitor ECG: combo may incr. risk of QT prolongation, cardiac arrhythmias (additive effects)

• amlodipine
Phenergan (promethazine)

+

amlodipine

1 interaction

Monitor/Modify Tx

promethazine + amlodipine

monitor BP: combo may incr. risk of hypotension (additive effects)

• anagrelide
Phenergan (promethazine)

+

anagrelide

1 interaction

Monitor/Modify Tx

promethazine + anagrelide

monitor ECG: combo may incr. risk of QT prolongation, cardiac arrhythmias (additive effects)

• apalutamide
Phenergan (promethazine)

+

apalutamide

1 interaction

Monitor/Modify Tx

promethazine + apalutamide

monitor ECG: combo may incr. risk of QT prolongation, cardiac arrhythmias, seizures (additive effects)

• aprocitentan
Phenergan (promethazine)

+

aprocitentan

1 interaction

Monitor/Modify Tx

promethazine + aprocitentan

monitor BP: combo may incr. risk of hypotension (additive effects)

• artemether/lumefantrine
Phenergan (promethazine)

+

artemether/ lumefantrine

1 interaction

Monitor/Modify Tx

promethazine + artemether/ lumefantrine

monitor ECG: combo may incr. risk of QT prolongation, cardiac arrhythmias (additive effects)

• articaine
Phenergan (promethazine)

+

articaine

1 interaction

Monitor/Modify Tx

promethazine + articaine

monitor BP: combo may incr. risk of hypotension (additive effects)

• atenolol
Phenergan (promethazine)

+

atenolol

1 interaction

Monitor/Modify Tx

promethazine + atenolol

monitor BP: combo may incr. risk of hypotension (additive effects)

• avanafil
Phenergan (promethazine)

+

avanafil

1 interaction

Monitor/Modify Tx

promethazine + avanafil

monitor BP: combo may incr. risk of hypotension, including orthostasis, syncope (additive effects)

• azilsartan medoxomil
Phenergan (promethazine)

+

azilsartan medoxomil

1 interaction

Monitor/Modify Tx

promethazine + azilsartan medoxomil

monitor BP: combo may incr. risk of hypotension (additive effects)

• azithromycin
Phenergan (promethazine)

+

azithromycin

1 interaction

Monitor/Modify Tx

promethazine + azithromycin

monitor ECG: combo may incr. risk of QT prolongation, cardiac arrhythmias (additive effects)

• benazepril
Phenergan (promethazine)

+

benazepril

1 interaction

Monitor/Modify Tx

promethazine + benazepril

monitor BP: combo may incr. risk of hypotension (additive effects)

• berberine
Phenergan (promethazine)

+

berberine

1 interaction

Monitor/Modify Tx

promethazine + berberine

monitor BP: combo may incr. risk of hypotension (additive effects)

• betaxolol
Phenergan (promethazine)

+

betaxolol

1 interaction

Monitor/Modify Tx

promethazine + betaxolol

monitor BP: combo may incr. risk of hypotension (additive effects)

• betaxolol ophthalmic
Phenergan (promethazine)

+

betaxolol ophthalmic

1 interaction

Monitor/Modify Tx

promethazine + betaxolol ophthalmic

monitor BP: combo may incr. risk of hypotension (additive effects)

• bethanechol
Phenergan (promethazine)

+

bethanechol

1 interaction

Monitor/Modify Tx

promethazine + bethanechol

monitor BP: combo may incr. risk of hypotension; may decr. efficacy of both drugs (additive effects; antagonistic effects)

• bexagliflozin
Phenergan (promethazine)

+

bexagliflozin

1 interaction

Monitor/Modify Tx

promethazine + bexagliflozin

monitor BP: combo may incr. risk of hypotension, including orthostasis (additive effects)

• bisoprolol
Phenergan (promethazine)

+

bisoprolol

1 interaction

Monitor/Modify Tx

promethazine + bisoprolol

monitor BP: combo may incr. risk of hypotension (additive effects)

• bortezomib
Phenergan (promethazine)

+

bortezomib

1 interaction

Monitor/Modify Tx

promethazine + bortezomib

monitor BP: combo may incr. risk of severe hypotension, including orthostasis, syncope (additive effects)

• bumetanide
Phenergan (promethazine)

+

bumetanide

1 interaction

Monitor/Modify Tx

promethazine + bumetanide

monitor BP: combo may incr. risk of hypotension (additive effects)

• bupivacaine
Phenergan (promethazine)

+

bupivacaine

1 interaction

Monitor/Modify Tx

promethazine + bupivacaine

monitor BP: combo may incr. risk of hypotension (additive effects)

• bupivacaine liposomal
Phenergan (promethazine)

+

bupivacaine liposomal

1 interaction

Monitor/Modify Tx

promethazine + bupivacaine liposomal

monitor BP: combo may incr. risk of hypotension (additive effects)

• bupropion
Phenergan (promethazine)

+

bupropion

1 interaction

Monitor/Modify Tx

promethazine + bupropion

consider lower bupropion doses: combo may incr. risk of seizures (additive effects)

• cabozantinib
Phenergan (promethazine)

+

cabozantinib

1 interaction

Monitor/Modify Tx

promethazine + cabozantinib

monitor ECG: combo may incr. risk of QT prolongation, cardiac arrhythmias (additive effects)

• canagliflozin
Phenergan (promethazine)

+

canagliflozin

1 interaction

Monitor/Modify Tx

promethazine + canagliflozin

monitor BP: combo may incr. risk of hypotension, including orthostasis, syncope (additive effects)

• candesartan cilexetil
Phenergan (promethazine)

+

candesartan cilexetil

1 interaction

Monitor/Modify Tx

promethazine + candesartan cilexetil

monitor BP: combo may incr. risk of hypotension (additive effects)

• captopril
Phenergan (promethazine)

+

captopril

1 interaction

Monitor/Modify Tx

promethazine + captopril

monitor BP: combo may incr. risk of hypotension (additive effects)

• carteolol ophthalmic
Phenergan (promethazine)

+

carteolol ophthalmic

1 interaction

Monitor/Modify Tx

promethazine + carteolol ophthalmic

monitor BP: combo may incr. risk of hypotension (additive effects)

• carvedilol
Phenergan (promethazine)

+

carvedilol

1 interaction

Monitor/Modify Tx

promethazine + carvedilol

monitor BP: combo may incr. risk of hypotension (additive effects)

• ceritinib
Phenergan (promethazine)

+

ceritinib

1 interaction

Monitor/Modify Tx

promethazine + ceritinib

monitor ECG, electrolytes: combo may incr. risk of QT prolongation, cardiac arrhythmias (additive effects)

• chloroprocaine
Phenergan (promethazine)

+

chloroprocaine

1 interaction

Monitor/Modify Tx

promethazine + chloroprocaine

monitor BP: combo may incr. risk of hypotension (additive effects)

• chloroquine
Phenergan (promethazine)

+

chloroquine

1 interaction

Monitor/Modify Tx

promethazine + chloroquine

monitor ECG: combo may incr. risk of QT prolongation, cardiac arrhythmias, seizures, extrapyramidal symptoms (additive effects)

• chlorothiazide
Phenergan (promethazine)

+

chlorothiazide

1 interaction

Monitor/Modify Tx

promethazine + chlorothiazide

monitor BP: combo may incr. risk of hypotension (additive effects)

• chlorthalidone
Phenergan (promethazine)

+

chlorthalidone

1 interaction

Monitor/Modify Tx

promethazine + chlorthalidone

monitor BP: combo may incr. risk of hypotension (additive effects)

• cilostazol
Phenergan (promethazine)

+

cilostazol

1 interaction

Monitor/Modify Tx

promethazine + cilostazol

monitor BP: combo may incr. risk of hypotension (additive effects)

• clarithromycin
Phenergan (promethazine)

+

clarithromycin

1 interaction

Monitor/Modify Tx

promethazine + clarithromycin

monitor ECG: combo may incr. risk of QT prolongation, cardiac arrhythmias (additive effects)

• clevidipine
Phenergan (promethazine)

+

clevidipine

1 interaction

Monitor/Modify Tx

promethazine + clevidipine

monitor BP: combo may incr. risk of hypotension (additive effects)

• clofarabine
Phenergan (promethazine)

+

clofarabine

1 interaction

Monitor/Modify Tx

promethazine + clofarabine

monitor BP: combo may incr. risk of severe hypotension (additive effects)

• clofazimine
Phenergan (promethazine)

+

clofazimine

1 interaction

Monitor/Modify Tx

promethazine + clofazimine

monitor ECG: combo may incr. risk of QT prolongation, cardiac arrhythmias (additive effects)

• coenzyme Q-10
Phenergan (promethazine)

+

coenzyme Q-10

1 interaction

Monitor/Modify Tx

promethazine + coenzyme Q-10

monitor BP: combo may incr. risk of hypotension (additive effects)

• dapagliflozin
Phenergan (promethazine)

+

dapagliflozin

1 interaction

Monitor/Modify Tx

promethazine + dapagliflozin

monitor BP: combo may incr. risk of hypotension, including orthostasis (additive effects)

• degarelix
Phenergan (promethazine)

+

degarelix

1 interaction

Monitor/Modify Tx

promethazine + degarelix

monitor ECG, electrolytes: combo may incr. risk of QT prolongation, cardiac arrhythmias (additive effects, androgen deprivation may prolong QT)

• denileukin diftitox
Phenergan (promethazine)

+

denileukin diftitox

1 interaction

Monitor/Modify Tx

promethazine + denileukin diftitox

monitor BP: combo may incr. risk of hypotension, including orthostasis (additive effects)

• dexmedetomidine
Phenergan (promethazine)

+

dexmedetomidine

1 interaction

Monitor/Modify Tx

promethazine + dexmedetomidine

monitor BP, HR, ECG, electrolytes; consider decr. dose of one or both drugs: combo may incr. risk of QT prolongation, cardiac arrhythmias, CNS and respiratory depression, psychomotor impairment, hypotension, including orthostasis, syncope (additive effects)

• diltiazem
Phenergan (promethazine)

+

diltiazem

1 interaction

Monitor/Modify Tx

promethazine + diltiazem

monitor BP: combo may incr. risk of hypotension (additive effects)

• dinutuximab
Phenergan (promethazine)

+

dinutuximab

1 interaction

Monitor/Modify Tx

promethazine + dinutuximab

monitor BP: combo may incr. risk of severe hypotension (additive effects)

• dipyridamole
Phenergan (promethazine)

+

dipyridamole

1 interaction

Monitor/Modify Tx

promethazine + dipyridamole

monitor BP: combo may incr. risk of severe hypotension (additive effects)

• disopyramide
Phenergan (promethazine)

+

disopyramide

1 interaction

Monitor/Modify Tx

promethazine + disopyramide

monitor ECG: combo may incr. risk of QT prolongation, cardiac arrhythmias, anticholinergic adverse effects (additive effects)

• dofetilide
Phenergan (promethazine)

+

dofetilide

1 interaction

Monitor/Modify Tx

promethazine + dofetilide

monitor ECG: combo may incr. risk of QT prolongation, cardiac arrhythmias (additive effects)

• donepezil
Phenergan (promethazine)

+

donepezil

1 interaction

Monitor/Modify Tx

promethazine + donepezil

monitor ECG: combo may incr. risk of seizures, QT prolongation, cardiac arrhythmias; may decr. efficacy of both drugs (additive effects; antagonistic effects)

• dordaviprone
Phenergan (promethazine)

+

dordaviprone

1 interaction

Monitor/Modify Tx

promethazine + dordaviprone

monitor ECG, electrolytes: combo may incr. risk of QT prolongation, cardiac arrhythmias (additive effects)

• doxazosin
Phenergan (promethazine)

+

doxazosin

1 interaction

Monitor/Modify Tx

promethazine + doxazosin

monitor BP, especially during doxazosin initiation/titration: combo may doxazosin levels, risk of hypotension (including orthostasis, syncope), other adverse effects (additive effects; absorption increased, slower GI transit due to anticholinergic effects)

• empagliflozin
Phenergan (promethazine)

+

empagliflozin

1 interaction

Monitor/Modify Tx

promethazine + empagliflozin

monitor BP: combo may incr. risk of hypotension, including orthostasis (additive effects)

• enalapril
Phenergan (promethazine)

+

enalapril

1 interaction

Monitor/Modify Tx

promethazine + enalapril

monitor BP: combo may incr. risk of hypotension (additive effects)

• enalaprilat
Phenergan (promethazine)

+

enalaprilat

1 interaction

Monitor/Modify Tx

promethazine + enalaprilat

monitor BP: combo may incr. risk of hypotension (additive effects)

• encorafenib
Phenergan (promethazine)

+

encorafenib

1 interaction

Monitor/Modify Tx

promethazine + encorafenib

monitor ECG, electrolytes: combo may incr. risk of QT prolongation, cardiac arrhythmias (additive effects)

• epirubicin
Phenergan (promethazine)

+

epirubicin

1 interaction

Monitor/Modify Tx

promethazine + epirubicin

monitor ECG: combo may incr. risk of QT prolongation, cardiac arrhythmias (additive effects)

• eplerenone
Phenergan (promethazine)

+

eplerenone

1 interaction

Monitor/Modify Tx

promethazine + eplerenone

monitor BP: combo may incr. risk of hypotension (additive effects)

• epoprostenol
Phenergan (promethazine)

+

epoprostenol

1 interaction

Monitor/Modify Tx

promethazine + epoprostenol

monitor BP: combo may incr. risk of severe hypotension (additive effects)

• eribulin
Phenergan (promethazine)

+

eribulin

1 interaction

Monitor/Modify Tx

promethazine + eribulin

monitor ECG: combo may incr. risk of QT prolongation, cardiac arrhythmias (additive effects)

• ertugliflozin
Phenergan (promethazine)

+

ertugliflozin

1 interaction

Monitor/Modify Tx

promethazine + ertugliflozin

monitor BP: combo may incr. risk of hypotension, including orthostasis (additive effects)

• erythromycin
Phenergan (promethazine)

+

erythromycin

1 interaction

Monitor/Modify Tx

promethazine + erythromycin

monitor ECG: combo may incr. risk of QT prolongation, cardiac arrhythmias; may decr. erythromycin efficacy when used for GI promotility (additive effects; antagonistic effects)

• esmolol
Phenergan (promethazine)

+

esmolol

1 interaction

Monitor/Modify Tx

promethazine + esmolol

monitor BP: combo may incr. risk of hypotension (additive effects)

• ethacrynic acid
Phenergan (promethazine)

+

ethacrynic acid

1 interaction

Monitor/Modify Tx

promethazine + ethacrynic acid

monitor BP: combo may incr. risk of hypotension (additive effects)

• etripamil nasal
Phenergan (promethazine)

+

etripamil nasal

1 interaction

Monitor/Modify Tx

promethazine + etripamil nasal

monitor BP: combo may incr. risk of hypotension, including syncope (additive effects)

• felodipine
Phenergan (promethazine)

+

felodipine

1 interaction

Monitor/Modify Tx

promethazine + felodipine

monitor BP: combo may incr. risk of hypotension (additive effects)

• fenoldopam
Phenergan (promethazine)

+

fenoldopam

1 interaction

Monitor/Modify Tx

promethazine + fenoldopam

monitor BP: combo may incr. risk of hypotension (additive effects)

• ferumoxytol
Phenergan (promethazine)

+

ferumoxytol

1 interaction

Monitor/Modify Tx

promethazine + ferumoxytol

monitor BP: combo may incr. risk of hypotension (additive effects)

• flaxseed
Phenergan (promethazine)

+

flaxseed

1 interaction

Monitor/Modify Tx

promethazine + flaxseed

monitor BP: combo may incr. risk of hypotension (additive effects)

• flecainide
Phenergan (promethazine)

+

flecainide

1 interaction

Monitor/Modify Tx

promethazine + flecainide

monitor ECG: combo may incr. risk of QT prolongation, cardiac arrhythmias (additive effects)

• fluorouracil
Phenergan (promethazine)

+

fluorouracil

1 interaction

Monitor/Modify Tx

promethazine + fluorouracil

monitor ECG: combo may incr. risk of QT prolongation, cardiac arrhythmias (additive effects)

• fosinopril
Phenergan (promethazine)

+

fosinopril

1 interaction

Monitor/Modify Tx

promethazine + fosinopril

monitor BP: combo may incr. risk of hypotension (additive effects)

• furosemide
Phenergan (promethazine)

+

furosemide

1 interaction

Monitor/Modify Tx

promethazine + furosemide

monitor BP: combo may incr. risk of hypotension (additive effects)

• garlic
Phenergan (promethazine)

+

garlic

1 interaction

Monitor/Modify Tx

promethazine + garlic

monitor BP w/ supplemental garlic; dietary intake OK: combo may incr. risk of hypotension (additive effects)

• gilteritinib
Phenergan (promethazine)

+

gilteritinib

1 interaction

Monitor/Modify Tx

promethazine + gilteritinib

monitor ECG, electrolytes, BP: combo may incr. risk of QT prolongation, cardiac arrhythmias, hypotension (additive effects)

• glasdegib
Phenergan (promethazine)

+

glasdegib

1 interaction

Monitor/Modify Tx

promethazine + glasdegib

monitor ECG: combo may incr. risk of QT prolongation, cardiac arrhythmias (additive effects)

• goserelin
Phenergan (promethazine)

+

goserelin

1 interaction

Monitor/Modify Tx

promethazine + goserelin

PROSTATE CANCER: monitor ECG, electrolytes; ALL OTHER INDICATIONS: consider monitoring ECG, electrolytes: combo may incr. risk of QT prolongation, cardiac arrhythmias, seizures (additive effects, androgen deprivation may prolong QT)

• histrelin
Phenergan (promethazine)

+

histrelin

1 interaction

Monitor/Modify Tx

promethazine + histrelin

consider monitoring ECG, electrolytes: combo may incr. risk of QT prolongation, cardiac arrhythmias (additive effects, androgen deprivation may prolong QT)

• hydralazine
Phenergan (promethazine)

+

hydralazine

1 interaction

Monitor/Modify Tx

promethazine + hydralazine

monitor BP: combo may incr. risk of hypotension (additive effects)

• hydrochlorothiazide
Phenergan (promethazine)

+

hydrochlorothiazide

1 interaction

Monitor/Modify Tx

promethazine + hydrochlorothiazide

monitor BP: combo may incr. hydrochlorothiazide levels, risk of hypotension, other adverse effects (absorption increased, additive effects)

• ibutilide
Phenergan (promethazine)

+

ibutilide

1 interaction

Monitor/Modify Tx

promethazine + ibutilide

monitor ECG: combo may incr. risk of QT prolongation, cardiac arrhythmias (additive effects)

• iloprost
Phenergan (promethazine)

+

iloprost

1 interaction

Monitor/Modify Tx

promethazine + iloprost

monitor BP: combo may incr. risk of severe hypotension, including orthostasis (additive effects)

• indapamide
Phenergan (promethazine)

+

indapamide

1 interaction

Monitor/Modify Tx

promethazine + indapamide

monitor BP: combo may incr. risk of hypotension, including orthostasis (additive effects)

• inotuzumab ozogamicin
Phenergan (promethazine)

+

inotuzumab ozogamicin

1 interaction

Monitor/Modify Tx

promethazine + inotuzumab ozogamicin

monitor ECG, electrolytes: combo may incr. risk of QT prolongation, cardiac arrhythmias (additive effects)

• iohexol
Phenergan (promethazine)

+

iohexol

1 interaction

Monitor/Modify Tx

promethazine + iohexol

if intrathecal iohexol use, D/C promethazine at least 48h before myelography, may resume at least 24h after procedure: combo may incr. risk of seizures (additive effects)

• iopamidol
Phenergan (promethazine)

+

iopamidol

1 interaction

Monitor/Modify Tx

promethazine + iopamidol

caution advised if intrathecal iopamidol use; consider holding promethazine at least 48h before and at least 24h after intrathecal iopamidol: combo may incr. risk of seizures (additive effects)

• irbesartan
Phenergan (promethazine)

+

irbesartan

1 interaction

Monitor/Modify Tx

promethazine + irbesartan

monitor BP: combo may incr. risk of hypotension (additive effects)

• iron sucrose
Phenergan (promethazine)

+

iron sucrose

1 interaction

Monitor/Modify Tx

promethazine + iron sucrose

monitor BP: combo may incr. risk of hypotension (additive effects)

• isosorbide dinitrate
Phenergan (promethazine)

+

isosorbide dinitrate

1 interaction

Monitor/Modify Tx

promethazine + isosorbide dinitrate

monitor BP: combo may incr. risk of severe hypotension, including syncope (additive effects)

• isosorbide mononitrate
Phenergan (promethazine)

+

isosorbide mononitrate

1 interaction

Monitor/Modify Tx

promethazine + isosorbide mononitrate

monitor BP: combo may incr. risk of severe hypotension, including syncope (additive effects)

• isradipine
Phenergan (promethazine)

+

isradipine

1 interaction

Monitor/Modify Tx

promethazine + isradipine

monitor BP: combo may incr. risk of hypotension (additive effects)

• ivosidenib
Phenergan (promethazine)

+

ivosidenib

1 interaction

Monitor/Modify Tx

promethazine + ivosidenib

monitor ECG, electrolytes: combo may incr. risk of QT prolongation, cardiac arrhythmias (additive effects)

• labetalol
Phenergan (promethazine)

+

labetalol

1 interaction

Monitor/Modify Tx

promethazine + labetalol

monitor BP: combo may incr. risk of hypotension (additive effects)

• landiolol
Phenergan (promethazine)

+

landiolol

1 interaction

Monitor/Modify Tx

promethazine + landiolol

monitor BP: combo may incr. risk of hypotension (additive effects)

• leuprolide
Phenergan (promethazine)

+

leuprolide

1 interaction

Monitor/Modify Tx

promethazine + leuprolide

PROSTATE CANCER: monitor ECG, electrolytes; ALL OTHER INDICATIONS: consider monitoring ECG, electrolytes: combo may incr. risk of QT prolongation, cardiac arrhythmias, seizures (additive effects, androgen deprivation may prolong QT)

• levobunolol ophthalmic
Phenergan (promethazine)

+

levobunolol ophthalmic

1 interaction

Monitor/Modify Tx

promethazine + levobunolol ophthalmic

monitor BP: combo may incr. risk of hypotension (additive effects)

• levofloxacin
Phenergan (promethazine)

+

levofloxacin

1 interaction

Monitor/Modify Tx

promethazine + levofloxacin

monitor ECG: combo may incr. risk of QT prolongation, cardiac arrhythmias (additive effects)

• levoketoconazole
Phenergan (promethazine)

+

levoketoconazole

1 interaction

Monitor/Modify Tx

promethazine + levoketoconazole

monitor ECG: combo may incr. risk of QT prolongation, cardiac arrhythmias (additive effects)

• lidocaine
Phenergan (promethazine)

+

lidocaine

1 interaction

Monitor/Modify Tx

promethazine + lidocaine

monitor BP: combo may incr. risk of seizures, hypotension (additive effects)

• lisinopril
Phenergan (promethazine)

+

lisinopril

1 interaction

Monitor/Modify Tx

promethazine + lisinopril

monitor BP: combo may incr. risk of hypotension (additive effects)

• losartan
Phenergan (promethazine)

+

losartan

1 interaction

Monitor/Modify Tx

promethazine + losartan

monitor BP: combo may incr. risk of hypotension (additive effects)

• lubiprostone
Phenergan (promethazine)

+

lubiprostone

1 interaction

Monitor/Modify Tx

promethazine + lubiprostone

monitor BP: combo may incr. risk of hypotension, including syncope (additive effects)

• macimorelin
Phenergan (promethazine)

+

macimorelin

1 interaction

Monitor/Modify Tx

promethazine + macimorelin

monitor ECG: combo may incr. risk of QT prolongation, cardiac arrhythmias (additive effects)

• magnesium sulfate
Phenergan (promethazine)

+

magnesium sulfate

1 interaction

Monitor/Modify Tx

promethazine + magnesium sulfate

monitor BP: combo may incr. risk of hypotension (additive effects)

• maraviroc
Phenergan (promethazine)

+

maraviroc

1 interaction

Monitor/Modify Tx

promethazine + maraviroc

monitor BP: combo may incr. risk of hypotension, including orthostasis (additive effects)

• mepivacaine
Phenergan (promethazine)

+

mepivacaine

1 interaction

Monitor/Modify Tx

promethazine + mepivacaine

monitor BP: combo may incr. risk of hypotension (additive effects)

• methylene blue injection
Phenergan (promethazine)

+

methylene blue injection

1 interaction

Monitor/Modify Tx

promethazine + methylene blue injection

monitor BP: combo may incr. risk of hypotension, including orthostasis (additive effects)

• metolazone
Phenergan (promethazine)

+

metolazone

1 interaction

Monitor/Modify Tx

promethazine + metolazone

monitor BP: combo may incr. risk of hypotension (additive effects)

• metoprolol
Phenergan (promethazine)

+

metoprolol

1 interaction

Monitor/Modify Tx

promethazine + metoprolol

monitor BP: combo may incr. risk of hypotension (additive effects)

• milrinone
Phenergan (promethazine)

+

milrinone

1 interaction

Monitor/Modify Tx

promethazine + milrinone

monitor BP: combo may incr. risk of hypotension (additive effects)

• minoxidil
Phenergan (promethazine)

+

minoxidil

1 interaction

Monitor/Modify Tx

promethazine + minoxidil

monitor BP: combo may incr. risk of hypotension (additive effects)

• moexipril
Phenergan (promethazine)

+

moexipril

1 interaction

Monitor/Modify Tx

promethazine + moexipril

monitor BP: combo may incr. risk of hypotension (additive effects)

• moxifloxacin
Phenergan (promethazine)

+

moxifloxacin

1 interaction

Monitor/Modify Tx

promethazine + moxifloxacin

monitor ECG: combo may incr. risk of QT prolongation, cardiac arrhythmias, seizures (additive effects)

• nadolol
Phenergan (promethazine)

+

nadolol

1 interaction

Monitor/Modify Tx

promethazine + nadolol

monitor BP: combo may incr. risk of hypotension (additive effects)

• nattokinase
Phenergan (promethazine)

+

nattokinase

1 interaction

Monitor/Modify Tx

promethazine + nattokinase

monitor BP: combo may incr. risk of hypotension (additive effects)

• naxitamab
Phenergan (promethazine)

+

naxitamab

1 interaction

Monitor/Modify Tx

promethazine + naxitamab

monitor BP: combo may incr. risk of hypotension, including orthostasis (additive effects)

• nebivolol
Phenergan (promethazine)

+

nebivolol

1 interaction

Monitor/Modify Tx

promethazine + nebivolol

monitor BP: combo may incr. risk of hypotension (additive effects)

• niacin (vitamin B3)
Phenergan (promethazine)

+

niacin (vitamin B3)

1 interaction

Monitor/Modify Tx

promethazine + niacin (vitamin B3)

monitor BP: combo may incr. risk of hypotension, including orthostasis (additive effects)

• nicardipine
Phenergan (promethazine)

+

nicardipine

1 interaction

Monitor/Modify Tx

promethazine + nicardipine

monitor BP: combo may incr. risk of hypotension (additive effects)

• nifedipine
Phenergan (promethazine)

+

nifedipine

1 interaction

Monitor/Modify Tx

promethazine + nifedipine

monitor BP: combo may incr. risk of hypotension (additive effects)

• nilotinib
Phenergan (promethazine)

+

nilotinib

1 interaction

Monitor/Modify Tx

promethazine + nilotinib

monitor ECG, electrolytes: combo may incr. risk of QT prolongation, cardiac arrhythmias (additive effects)

• nimodipine
Phenergan (promethazine)

+

nimodipine

1 interaction

Monitor/Modify Tx

promethazine + nimodipine

monitor BP: combo may incr. risk of hypotension (additive effects)

• nisoldipine
Phenergan (promethazine)

+

nisoldipine

1 interaction

Monitor/Modify Tx

promethazine + nisoldipine

monitor BP: combo may incr. risk of hypotension (additive effects)

• nitric oxide
Phenergan (promethazine)

+

nitric oxide

1 interaction

Monitor/Modify Tx

promethazine + nitric oxide

monitor BP: combo may incr. risk of hypotension (additive effects)

• nitrite
Phenergan (promethazine)

+

nitrite

1 interaction

Monitor/Modify Tx

promethazine + nitrite

monitor BP: combo may incr. risk of severe or life-threatening hypotension, including syncope (additive effects)

• nitroglycerin
Phenergan (promethazine)

+

nitroglycerin

1 interaction

Monitor/Modify Tx

promethazine + nitroglycerin

monitor BP: combo may incr. risk of severe hypotension, including orthostasis, syncope (additive effects)

• nitroprusside
Phenergan (promethazine)

+

nitroprusside

1 interaction

Monitor/Modify Tx

promethazine + nitroprusside

monitor BP: combo may incr. risk of severe or life-threatening hypotension (additive effects)

• obinutuzumab
Phenergan (promethazine)

+

obinutuzumab

1 interaction

Monitor/Modify Tx

promethazine + obinutuzumab

monitor BP: combo may incr. risk of hypotension (additive effects)

• olmesartan medoxomil
Phenergan (promethazine)

+

olmesartan medoxomil

1 interaction

Monitor/Modify Tx

promethazine + olmesartan medoxomil

monitor BP: combo may incr. risk of hypotension (additive effects)

• ondansetron
Phenergan (promethazine)

+

ondansetron

1 interaction

Monitor/Modify Tx

promethazine + ondansetron

monitor ECG: combo may incr. risk of QT prolongation, cardiac arrhythmias (additive effects)

• osimertinib
Phenergan (promethazine)

+

osimertinib

1 interaction

Monitor/Modify Tx

promethazine + osimertinib

monitor ECG, electrolytes: combo may incr. risk of QT prolongation, cardiac arrhythmias (additive effects)

• pacritinib
Phenergan (promethazine)

+

pacritinib

1 interaction

Monitor/Modify Tx

promethazine + pacritinib

monitor ECG, electrolytes: combo may incr. risk of QT prolongation, cardiac arrhythmias (additive effects)

• palonosetron
Phenergan (promethazine)

+

palonosetron

1 interaction

Monitor/Modify Tx

promethazine + palonosetron

monitor ECG: combo may incr. risk of QT prolongation, cardiac arrhythmias (additive effects)

• palopegteriparatide
Phenergan (promethazine)

+

palopegteriparatide

1 interaction

Monitor/Modify Tx

promethazine + palopegteriparatide

monitor BP: combo may incr. risk of hypotension, including orthostasis, syncope (additive effects)

• pasireotide
Phenergan (promethazine)

+

pasireotide

1 interaction

Monitor/Modify Tx

promethazine + pasireotide

monitor ECG: combo may incr. risk of QT prolongation, cardiac arrhythmias (additive effects)

• pentamidine
Phenergan (promethazine)

+

pentamidine

1 interaction

Monitor/Modify Tx

promethazine + pentamidine

monitor ECG, BP; risk may be lower w/ nebulized pentamidine: combo may incr. risk of QT prolongation, cardiac arrhythmias, severe or life-threatening hypotension (additive effects)

• perindopril
Phenergan (promethazine)

+

perindopril

1 interaction

Monitor/Modify Tx

promethazine + perindopril

monitor BP: combo may incr. risk of hypotension (additive effects)

• phenoxybenzamine
Phenergan (promethazine)

+

phenoxybenzamine

1 interaction

Monitor/Modify Tx

promethazine + phenoxybenzamine

monitor BP: combo may incr. risk of hypotension (additive effects)

• phentolamine
Phenergan (promethazine)

+

phentolamine

1 interaction

Monitor/Modify Tx

promethazine + phentolamine

monitor BP: combo may incr. risk of hypotension (additive effects)

• pindolol
Phenergan (promethazine)

+

pindolol

1 interaction

Monitor/Modify Tx

promethazine + pindolol

monitor BP: combo may incr. risk of hypotension (additive effects)

• prazosin
Phenergan (promethazine)

+

prazosin

1 interaction

Monitor/Modify Tx

promethazine + prazosin

monitor BP, especially during prazosin initiation/titration: combo may incr. risk of hypotension, including orthostasis, syncope (additive effects)

• procainamide
Phenergan (promethazine)

+

procainamide

1 interaction

Monitor/Modify Tx

promethazine + procainamide

monitor ECG: combo may incr. risk of QT prolongation, cardiac arrhythmias (additive effects)

• propafenone
Phenergan (promethazine)

+

propafenone

1 interaction

Monitor/Modify Tx

promethazine + propafenone

monitor ECG, BP: combo may incr. risk of QT prolongation, cardiac arrhythmias, hypotension (additive effects)

• propranolol
Phenergan (promethazine)

+

propranolol

1 interaction

Monitor/Modify Tx

promethazine + propranolol

monitor BP: combo may incr. risk of hypotension (additive effects)

• quinapril
Phenergan (promethazine)

+

quinapril

1 interaction

Monitor/Modify Tx

promethazine + quinapril

monitor BP: combo may incr. risk of hypotension (additive effects)

• quinidine (antiarrhythmic)
Phenergan (promethazine)

+

quinidine (antiarrhythmic)

1 interaction

Monitor/Modify Tx

promethazine + quinidine (antiarrhythmic)

monitor ECG: combo may incr. risk of QT prolongation, cardiac arrhythmias, anticholinergic adverse effects (additive effects)

• quinidine (CYP2D6 inhibitor)
Phenergan (promethazine)

+

quinidine (CYP2D6 inhibitor)

1 interaction

Monitor/Modify Tx

promethazine + quinidine (CYP2D6 inhibitor)

monitor ECG: combo may incr. risk of QT prolongation, cardiac arrhythmias, anticholinergic adverse effects (additive effects)

• quinine
Phenergan (promethazine)

+

quinine

1 interaction

Monitor/Modify Tx

promethazine + quinine

monitor ECG: combo may incr. risk of QT prolongation, cardiac arrhythmias, seizures (additive effects)

• ramipril
Phenergan (promethazine)

+

ramipril

1 interaction

Monitor/Modify Tx

promethazine + ramipril

monitor BP: combo may incr. risk of hypotension (additive effects)

• revumenib
Phenergan (promethazine)

+

revumenib

1 interaction

Monitor/Modify Tx

promethazine + revumenib

monitor ECG, electrolytes: combo may incr. risk of QT prolongation, cardiac arrhythmias (additive effects)

• ribociclib
Phenergan (promethazine)

+

ribociclib

1 interaction

Monitor/Modify Tx

promethazine + ribociclib

monitor ECG, electrolytes: combo may incr. risk of QT prolongation, cardiac arrhythmias (additive effects)

• riociguat
Phenergan (promethazine)

+

riociguat

1 interaction

Monitor/Modify Tx

promethazine + riociguat

monitor BP: combo may incr. risk of severe hypotension (additive effects)

• romidepsin
Phenergan (promethazine)

+

romidepsin

1 interaction

Monitor/Modify Tx

promethazine + romidepsin

monitor ECG: combo may incr. risk of QT prolongation, cardiac arrhythmias (additive effects)

• ropivacaine
Phenergan (promethazine)

+

ropivacaine

1 interaction

Monitor/Modify Tx

promethazine + ropivacaine

monitor BP: combo may incr. risk of hypotension (additive effects)

• rucaparib
Phenergan (promethazine)

+

rucaparib

1 interaction

Monitor/Modify Tx

promethazine + rucaparib

monitor ECG: combo may incr. risk of QT prolongation, cardiac arrhythmias (additive effects)

• sacubitril
Phenergan (promethazine)

+

sacubitril

1 interaction

Monitor/Modify Tx

promethazine + sacubitril

monitor BP: combo may incr. risk of hypotension, including orthostasis (additive effects)

• selpercatinib
Phenergan (promethazine)

+

selpercatinib

1 interaction

Monitor/Modify Tx

promethazine + selpercatinib

monitor ECG, electrolytes: combo may incr. risk of QT prolongation, cardiac arrhythmias (additive effects)

• sildenafil
Phenergan (promethazine)

+

sildenafil

1 interaction

Monitor/Modify Tx

promethazine + sildenafil

monitor BP: combo may incr. risk of hypotension (additive effects)

• silodosin
Phenergan (promethazine)

+

silodosin

1 interaction

Monitor/Modify Tx

promethazine + silodosin

monitor BP: combo may incr. risk of hypotension, including orthostasis, syncope (additive effects)

• sodium ferric gluconate complex
Phenergan (promethazine)

+

sodium ferric gluconate complex

1 interaction

Monitor/Modify Tx

promethazine + sodium ferric gluconate complex

monitor BP: combo may incr. risk of hypotension (additive effects)

• sotagliflozin
Phenergan (promethazine)

+

sotagliflozin

1 interaction

Monitor/Modify Tx

promethazine + sotagliflozin

monitor BP: combo may incr. risk of hypotension, including orthostasis (additive effects)

• sparsentan
Phenergan (promethazine)

+

sparsentan

1 interaction

Monitor/Modify Tx

promethazine + sparsentan

monitor BP: combo may incr. risk of hypotension, including orthostasis, syncope (additive effects)

• spironolactone
Phenergan (promethazine)

+

spironolactone

1 interaction

Monitor/Modify Tx

promethazine + spironolactone

monitor BP: combo may incr. risk of hypotension (additive effects)

• tadalafil
Phenergan (promethazine)

+

tadalafil

1 interaction

Monitor/Modify Tx

promethazine + tadalafil

monitor BP: combo may incr. risk of hypotension (additive effects)

• tagraxofusp
Phenergan (promethazine)

+

tagraxofusp

1 interaction

Monitor/Modify Tx

promethazine + tagraxofusp

monitor BP: combo may incr. risk of hypotension (additive effects)

• taletrectinib
Phenergan (promethazine)

+

taletrectinib

1 interaction

Monitor/Modify Tx

promethazine + taletrectinib

monitor ECG, electrolytes: combo may incr. risk of QT prolongation, cardiac arrhythmias (additive effects)

• tamsulosin
Phenergan (promethazine)

+

tamsulosin

1 interaction

Monitor/Modify Tx

promethazine + tamsulosin

monitor BP: combo may incr. risk of hypotension, including orthostasis, syncope (additive effects)

• taurine
Phenergan (promethazine)

+

taurine

1 interaction

Monitor/Modify Tx

promethazine + taurine

monitor BP: combo may incr. risk of hypotension (additive effects)

• telavancin
Phenergan (promethazine)

+

telavancin

1 interaction

Monitor/Modify Tx

promethazine + telavancin

monitor ECG: combo may incr. risk of QT prolongation, cardiac arrhythmias (additive effects)

• telmisartan
Phenergan (promethazine)

+

telmisartan

1 interaction

Monitor/Modify Tx

promethazine + telmisartan

monitor BP: combo may incr. risk of hypotension (additive effects)

• terazosin
Phenergan (promethazine)

+

terazosin

1 interaction

Monitor/Modify Tx

promethazine + terazosin

monitor BP, especially during terazosin initiation/titration: combo may incr. risk of hypotension, including orthostasis, syncope (additive effects)

• timolol
Phenergan (promethazine)

+

timolol

1 interaction

Monitor/Modify Tx

promethazine + timolol

monitor BP: combo may incr. risk of hypotension (additive effects)

• timolol ophthalmic
Phenergan (promethazine)

+

timolol ophthalmic

1 interaction

Monitor/Modify Tx

promethazine + timolol ophthalmic

monitor BP: combo may incr. risk of hypotension (additive effects)

• torsemide
Phenergan (promethazine)

+

torsemide

1 interaction

Monitor/Modify Tx

promethazine + torsemide

monitor BP: combo may incr. risk of hypotension (additive effects)

• trandolapril
Phenergan (promethazine)

+

trandolapril

1 interaction

Monitor/Modify Tx

promethazine + trandolapril

monitor BP: combo may incr. risk of hypotension (additive effects)

• treprostinil
Phenergan (promethazine)

+

treprostinil

1 interaction

Monitor/Modify Tx

promethazine + treprostinil

monitor BP: combo may incr. risk of severe hypotension, including syncope (additive effects)

• triamterene
Phenergan (promethazine)

+

triamterene

1 interaction

Monitor/Modify Tx

promethazine + triamterene

monitor BP: combo may incr. risk of hypotension (additive effects)

• triclabendazole
Phenergan (promethazine)

+

triclabendazole

1 interaction

Monitor/Modify Tx

promethazine + triclabendazole

monitor ECG: combo may incr. risk of QT prolongation, cardiac arrhythmias (additive effects)

• trifluridine
Phenergan (promethazine)

+

trifluridine

1 interaction

Monitor/Modify Tx

promethazine + trifluridine

monitor ECG: combo may incr. risk of QT prolongation, cardiac arrhythmias (additive effects)

• triptorelin
Phenergan (promethazine)

+

triptorelin

1 interaction

Monitor/Modify Tx

promethazine + triptorelin

PROSTATE CANCER: monitor ECG, electrolytes; ALL OTHER INDICATIONS: consider monitoring ECG, electrolytes: combo may incr. risk of QT prolongation, cardiac arrhythmias, seizures (additive effects, androgen deprivation may prolong QT)

• valsartan
Phenergan (promethazine)

+

valsartan

1 interaction

Monitor/Modify Tx

promethazine + valsartan

monitor BP: combo may incr. risk of hypotension (additive effects)

• vardenafil
Phenergan (promethazine)

+

vardenafil

1 interaction

Monitor/Modify Tx

promethazine + vardenafil

monitor BP: combo may incr. risk of hypotension (additive effects)

• vemurafenib
Phenergan (promethazine)

+

vemurafenib

1 interaction

Monitor/Modify Tx

promethazine + vemurafenib

monitor ECG, electrolytes: combo may incr. risk of QT prolongation, cardiac arrhythmias (additive effects)

• verapamil
Phenergan (promethazine)

+

verapamil

1 interaction

Monitor/Modify Tx

promethazine + verapamil

monitor BP: combo may incr. risk of hypotension (additive effects)

• vosoritide
Phenergan (promethazine)

+

vosoritide

1 interaction

Monitor/Modify Tx

promethazine + vosoritide

monitor BP: combo may incr. risk of hypotension (additive effects)

• warfarin
Phenergan (promethazine)

+

warfarin

1 interaction

Monitor/Modify Tx

promethazine + warfarin

monitor INR: combo may decr. warfarin efficacy (mechanism unknown)

• yohimbe
Phenergan (promethazine)

+

yohimbe

1 interaction

Monitor/Modify Tx

promethazine + yohimbe

monitor BP, especially w/ high yohimbe doses: combo may incr. risk of hypotension (additive effects)

• ziftomenib
Phenergan (promethazine)

+

ziftomenib

1 interaction

Monitor/Modify Tx

promethazine + ziftomenib

monitor ECG, electrolytes: combo may incr. risk of QT prolongation, cardiac arrhythmias (additive effects)