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Flomax
tamsulosin
Adult Dosing .
Dosage forms: CAP: 0.4 mg
BPH
- [0.4 mg PO qd]
- Info: may incr. to 0.8 mg PO qd after 2-4wk; give 30min after same meal qd; do not open cap
nephrolithiasis (off-label)
- [0.4 mg PO qd]
- Info: give 30min after same meal qd; do not open cap
renal dosing
- [see below]
- CrCl >10: no adjustment; CrCl <10: not defined
- HD/PD: not defined
hepatic dosing
- [see below]
- Child-Pugh Class A or B: no adjustment; Child-Pugh Class C: not defined
Peds Dosing .
- Dosage forms: CAP: 0.4 mg
nephrolithiasis (off-label)
- [>4 yo]
- Dose: 0.4 mg PO qd; Info: give 30min after same meal qd; do not open cap
renal dosing
- [not defined]
- renal impairment: consider adult renal dosing for guidance
- HD/PD: consider adult renal dosing for guidance
hepatic dosing
- [not defined]
- hepatic impairment: consider adult hepatic dosing for guidance
Contraindications / Cautions .
- hypersensitivity to drug or ingredient
- caution: hypersensitivity to sulfonamides
- caution: CYP2D6 poor metabolizers
- caution: cataract surgery
- caution: glaucoma surgery
Drug Interactions .
Overview
tamsulosin
alpha-1 blocker
- CYP2D6 substrate
- CYP3A4 substrate
- hypotensive effects
Avoid/Use Alternative
- abiraterone acetate
- adagrasib
- aldesleukin
- atazanavir
- bupropion
- capivasertib
- ceritinib
- chloramphenicol
- cinacalcet
- clarithromycin
- cobicistat
- dacomitinib
- doxazosin
- duloxetine
- eliglustat
- fluoxetine
- givosiran
- idelalisib
- iloperidone
- itraconazole
- ketoconazole
- levoketoconazole
- lofexidine
- lonafarnib
- lopinavir/ritonavir
- mavorixafor
- mifepristone
- mirabegron
- nefazodone
- nelfinavir
- netupitant
- paroxetine
- posaconazole
- prazosin
- quinidine (antiarrhythmic)
- quinidine (CYP2D6 inhibitor)
- ribociclib
- ritonavir
- rolapitant
- tadalafil
- tamsulosin
- terazosin
- terbinafine
- thioridazine
- tipranavir
- tucatinib
- voriconazole
Monitor/Modify Tx
- acebutolol
- alfentanil
- alfuzosin
- aliskiren
- amantadine
- amifostine
- amiloride
- amitriptyline
- amlodipine
- amoxapine
- apomorphine
- apraclonidine ophthalmic
- aprepitant
- aprocitentan
- aripiprazole bimonthly injection
- aripiprazole lauroxil
- aripiprazole monthly injection
- aripiprazole oral
- articaine
- asenapine
- atenolol
- avacopan
- avanafil
- azilsartan medoxomil
- benazepril
- berberine
- berotralstat
- betaxolol
- betaxolol ophthalmic
- bethanechol
- bexagliflozin
- bisoprolol
- bortezomib
- brexpiprazole
- brimonidine ophthalmic
- brimonidine topical
- bromocriptine
- bumetanide
- bupivacaine
- bupivacaine liposomal
- buprenorphine
- butorphanol
- cabergoline
- canagliflozin
- candesartan cilexetil
- cannabis
- captopril
- cariprazine
- carteolol ophthalmic
- carvedilol
- chloroprocaine
- chlorothiazide
- chlorpromazine
- chlorthalidone
- cilostazol
- cimetidine
- ciprofloxacin
- clevidipine
- clofarabine
- clofazimine
- clomipramine
- clonidine
- clozapine
- codeine
- coenzyme Q-10
- conivaptan
- crizotinib
- cyclosporine
- danazol
- dapagliflozin
- darunavir
- denileukin diftitox
- desflurane
- desipramine
- dexmedetomidine
- dexmedetomidine injection
- dihydrocodeine
- diltiazem
- dinutuximab
- dipyridamole
- doxepin
- dronabinol
- dronedarone
- duvelisib
- empagliflozin
- enalapril
- enalaprilat
- entacapone
- entrectinib
- eplerenone
- epoprostenol
- ertugliflozin
- erythromycin
- esmolol
- ethacrynic acid
- ethanol
- fedratinib
- felodipine
- fenoldopam
- fentanyl
- ferumoxytol
- flaxseed
- flibanserin
- fluconazole
- fluphenazine
- fosamprenavir
- fosinopril
- foslevodopa
- furosemide
- garlic
- gilteritinib
- grapefruit
- guanfacine
- haloperidol
- hydralazine
- hydrochlorothiazide
- hydrocodone
- hydromorphone
- iloprost
- iloprost inhaled
- imatinib
- imipramine
- indapamide
- irbesartan
- iron sucrose
- isavuconazonium
- isocarboxazid
- isoflurane
- isosorbide dinitrate
- isosorbide mononitrate
- isradipine
- labetalol
- landiolol
- lefamulin
- lenacapavir
- letermovir
- levobunolol ophthalmic
- levodopa
- levorphanol
- lidocaine
- lisinopril
- losartan
- loxapine
- lubiprostone
- lumateperone
- lurasidone
- magnesium sulfate
- maraviroc
- meperidine
- mepivacaine
- methadone
- methohexital
- methyldopa
- methylene blue injection
- metolazone
- metoprolol
- midazolam
- milrinone
- minoxidil
- mirtazapine
- moexipril
- molindone
- morphine
- nadolol
- nalbuphine
- nattokinase
- naxitamab
- nebivolol
- niacin (vitamin B3)
- nicardipine
- nifedipine
- nilotinib
- nimodipine
- nirogacestat
- nisoldipine
- nitric oxide
- nitrite
- nitroglycerin
- nitroprusside
- nortriptyline
- olanzapine
- oliceridine
- olmesartan medoxomil
- opicapone
- opium
- oxazepam
- oxycodone
- oxymorphone
- paliperidone
- palopegteriparatide
- pentamidine
- pentazocine
- pentobarbital
- perindopril
- perphenazine
- phenelzine
- phenobarbital
- phenoxybenzamine
- phentolamine
- pindolol
- pramipexole
- procarbazine
- prochlorperazine
- promethazine
- propafenone
- propofol
- propranolol
- protriptyline
- quetiapine
- quinapril
- ramipril
- rasagiline
- remifentanil
- remimazolam
- riociguat
- risperidone
- ropinirole
- ropivacaine
- rotigotine transdermal
- sacubitril
- safinamide
- selegiline
- selegiline transdermal
- sevoflurane
- sildenafil
- silodosin
- sodium ferric gluconate complex
- sotagliflozin
- sotalol
- sparsentan
- spironolactone
- sufentanil
- tagraxofusp
- tapentadol
- taurine
- telmisartan
- thalidomide
- thiothixene
- timolol
- timolol ophthalmic
- tizanidine
- tolcapone
- torsemide
- tramadol
- trandolapril
- tranylcypromine
- trazodone
- treprostinil
- triamterene
- trifluoperazine
- trimipramine
- valsartan
- vardenafil
- verapamil
- vosoritide
- warfarin
- yohimbe
- ziprasidone
Adverse Reactions .
Serious Reactions
- hypotension, orthostatic
- syncope
- arrhythmia
- hypersensitivity rxn
- Stevens-Johnson syndrome
- erythema multiforme
- exfoliative dermatitis
- intraoperative floppy iris syndrome
- priapism
Common Reactions
- abnormal ejaculation
- dizziness
- rhinitis
- infection
- asthenia
- pharyngitis
- back pain
- somnolence
- cough
- sinusitis
- libido decr.
Safety/Monitoring .
Monitoring Parameters
no routine tests recommended
Look/Sound-Alike Drug Names
Flomax confused with: Flonase; Flovent; Foltx; Fosamax; Nolvadex; Volmax
tamsulosin confused with: tacrolimus; tamoxifen; tegaserod; Tensilon; terazosin; tolterodine
Pregnancy/Lactation .
Pregnancy
Clinical Summary
weigh risk/benefit during pregnancy; no known risk of fetal harm based on limited human data; no known risk of fetal harm based on animal data at 50x recommended human dose
Lactation
Clinical Summary
weigh risk/benefit while breastfeeding; no human data available to assess risk of infant harm or effects on milk production
Pharmacology .
Metabolism: liver extensively; CYP450: 2D6, 3A4 substrate
Excretion: urine 76% (<10% unchanged), feces 21%; Half-life: 14-15h
Subclass: Benign Prostatic Hyperplasia (BPH) ; Nephrolithiasis
Mechanism of Action
selectively antagonizes prostate alpha-1a adrenergic receptors, relaxing smooth muscle and improving urine flow (peripherally-acting alpha blocker)
Formulary .
No Formulary Selected
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