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Bactrim DS
sulfamethoxazole/ trimethoprim
Adult Dosing .
Dosage forms: TAB: 800 mg/160 mg
Special Note
- [strength clarification]
- Info: dosing based on trimethoprim (TMP) component
infections, mild-moderate bacterial
- [160 mg TMP PO bid]
- Alt: 8-10 mg/kg/day TMP PO divided q6-12h; Info: dose, duration varies with infection type, severity; consider using adjusted wt of ideal body wt + 0.4 x (actual body wt - ideal body wt) if >8 mg/kg/day in obese patients
UTI
- [mild-moderate infection]
- Dose: 160 mg TMP PO bid x3-14 days; Info: duration varies with infection type, severity; give x3 days if uncomplicated cystitis; refer to IDSA guidelines
- [severe infection (off-label)]
- Dose: 8-10 mg/kg/day TMP PO divided q6-12h for up to 14 days; Info: dose, duration varies with infection type; give x14 days if pyelonephritis, may give with ceftriaxone or gentamicin; refer to IDSA guidelines; IV route preferred; consider using adjusted wt of ideal body wt + 0.4 x (actual body wt - ideal body wt) if >8 mg/kg/day in obese patients
PCP tx
- [15-20 mg/kg/day TMP PO divided q6-8h x21 days]
- Info: consider using adjusted wt of ideal body wt + 0.4 x (actual body wt - ideal body wt) in obese patients
PCP prophylaxis
- [80-160 mg TMP PO qd]
- Alt: 160 mg TMP PO 3x/wk
meningitis, bacterial (off-label)
- [10-20 mg/kg/day TMP PO divided q6-12h for at least 21 days]
- Info: for Listeria monocytogenes; dose, duration varies with infection severity; IV route preferred; not 1st-line tx; consider using adjusted wt of ideal body wt + 0.4 x (actual body wt - ideal body wt) in obese patients
salmonellosis, acute (off-label)
- [160 mg TMP PO bid]
- Info: duration varies with infection severity; not 1st-line tx
salmonella, chronic carrier (off-label)
- [160 mg TMP PO bid x3mo]
- Info: not 1st-line tx
yersiniosis, severe (off-label)
- [160 mg TMP PO bid]
- Info: duration varies with infection severity
typhoid fever (off-label)
- [160 mg TMP PO bid up to 14 days]
- Info: for susceptible strains only
toxoplasmosis tx (off-label)
- [10 mg/kg/day TMP PO divided bid for at least 6wk]
- Info: duration varies with infection severity; not 1st-line tx; consider using adjusted wt of ideal body wt + 0.4 x (actual body wt - ideal body wt) in obese patients
toxoplasmosis prophylaxis, primary (off-label)
- [160 mg TMP PO qd]
- Alt: 80 mg TMP PO qd; 160 mg TMP PO 3x/wk; Info: refer to NIH HIV opportunistic infection guideline for tx duration
toxoplasmosis prophylaxis, secondary (off-label)
- [160 mg TMP PO bid]
- Alt: 160 mg TMP PO qd; Info: not 1st-line agent; refer to NIH HIV opportunistic infection guideline for tx duration
pertussis (off-label)
- [160 mg TMP PO bid x14 days]
granuloma inguinale (off-label)
- [160 mg TMP PO bid for at least 3wk]
- Info: may extend tx if not healed after 3wk; not 1st-line agent
cyclosporiasis (off-label)
- [160 mg TMP PO bid x7-10 days]
- Info: for immunocompetent patients; may extend duration in HIV patients
renal dosing
- [>10 mg/kg/day TMP regimen]
- CrCl 10-30: 5 mg/kg/dose TMP q12h; CrCl <10: 5 mg/kg/dose TMP q24h
- HD: 5 mg/kg/dose TMP q24h, on dialysis days administer after dialysis; consider supplement if next maintenance dose not due right after dialysis; PD: not defined
- [2-3x/wk regimen]
- renal impairment: not defined
- HD/PD: not defined
- [all other regimens]
- CrCl 15-30: decr. usual dose by 50%; CrCl <15: avoid use
- HD: 160 mg TMP x1, then decr. usual dose by 50%, on dialysis days administer after dialysis; consider supplement if next maintenance dose not due right after dialysis; PD: 160 mg TMP q24h; no supplement
hepatic dosing
- [see below]
- hepatic impairment: not defined, caution advised; Info: contraindicated if significant impairment
Peds Dosing .
- Dosage forms: TAB: 800 mg/160 mg
Special Note
- [strength clarification]
- Info: dosing based on trimethoprim (TMP) component
infections, mild-moderate bacterial
- [2 mo and older]
- Dose: 8-10 mg/kg/day TMP PO divided q6-12h; Info: dose, duration varies with infection type, severity
PCP tx
- [2 mo and older]
- Dose: 15-20 mg/kg/day TMP PO divided q6-8h x21 days
PCP prophylaxis
- [1 mo-12 yo (off-label)]
- Dose: 5-10 mg/kg/day TMP PO divided bid 2-3x/wk; Max: 320 mg/day TMP; Alt: 5-10 mg/kg/dose TMP PO qd; Info: may give on consecutive days or alternate days when given 2-3x/wk
- [13 yo and older]
- Dose: 80-160 mg TMP PO qd; Alt: 160 mg TMP PO 3x/wk
UTI tx
- [2-23 mo (off-label)]
- Dose: 8-12 mg/kg/day TMP PO divided q6-12h x7-14 days; Max: 320 mg/day TMP; Info: dose, duration varies with infection type, severity
- [mild-moderate infection, 2 yo and older]
- Dose: 8 mg/kg/day TMP PO divided bid x3-10 days; Max: 320 mg/day TMP; Info: duration varies with infection type, severity
- [severe infection, 2 yo and older (off-label)]
- Dose: 8-10 mg/kg/day TMP PO divided q6-12h up to 14 days; Info: dose, duration varies with infection type; IV route preferred
UTI prophylaxis (off-label)
- [2 mo and older]
- Dose: 2-4 mg/kg/dose TMP PO qd; Alt: 5 mg/kg/dose TMP PO 2x/wk
meningitis, bacterial (off-label)
- [2 mo and older]
- Dose: 10-20 mg/kg/day TMP PO divided q6-12h for at least 21 days; Info: for Listeria monocytogenes; dose, duration varies with infection severity; IV route preferred; not 1st-line tx
salmonellosis, acute (off-label)
- [2 mo and older, <32 kg]
- Dose: 10 mg/kg/day TMP PO divided bid; Info: duration varies with infection severity; not 1st-line tx
- [2 mo and older, >32 kg]
- Dose: 320 mg/day TMP PO divided bid; Info: duration varies with infection severity; not 1st-line tx
salmonella, chronic carrier (off-label)
- [2 mo and older, <32 kg]
- Dose: 10 mg/kg/day TMP PO divided bid x3mo; Info: not 1st-line tx
- [2 mo and older, >32 kg]
- Dose: 320 mg/day TMP PO divided bid x3mo; Info: not 1st-line tx
yersiniosis, severe (off-label)
- [2 mo and older, <32 kg]
- Dose: 10 mg/kg/day TMP PO divided bid; Info: duration varies with infection severity
- [2 mo and older, >32 kg]
- Dose: 320 mg/day TMP PO divided bid; Info: duration varies with infection severity
typhoid fever (off-label)
- [2 mo and older]
- Dose: 8 mg/kg/day TMP PO divided q6-12h up to 14 days; Max: 320 mg/day TMP; Info: for susceptible strains only
toxoplasmosis tx (off-label)
- [13 yo and older]
- Dose: 10 mg/kg/day TMP PO divided bid for at least 6wk; Info: duration varies with infection severity; not 1st-line tx
toxoplasmosis prophylaxis, primary (off-label)
- [1 mo-12 yo]
- Dose: 150 mg/m^2/day TMP PO qd; Max: 160 mg/day TMP; Info: refer to NIH HIV opportunistic infection guideline for tx duration
- [13 yo and older]
- Dose: 160 mg TMP PO qd; Alt: 80 mg TMP PO qd; 160 mg TMP PO 3x/wk; Info: refer to NIH HIV opportunistic infection guideline for tx duration
toxoplasmosis prophylaxis, secondary (off-label)
- [1 mo-12 yo]
- Dose: 150 mg/m^2/dose TMP PO qd; Max: 320 mg/day TMP; Info: not 1st-line agent; refer to NIH HIV opportunistic infection guideline for tx duration
- [13 yo and older]
- Dose: 160 mg TMP PO bid; Alt: 160 mg TMP PO qd; Info: not 1st-line agent; refer to NIH HIV opportunistic infection guideline for tx duration
pertussis (off-label)
- [2 mo and older]
- Dose: 8 mg/kg/day TMP PO divided bid x14 days
granuloma inguinale (off-label)
- [adolescents]
- Dose: 160 mg TMP PO bid for at least 3wk; Info: may extend tx if not healed after 3wk; not 1st-line agent
brucellosis (off-label)
- [1 mo-7 yo]
- Dose: 8-10 mg/kg/day TMP PO divided bid x6wk; Max: 480 mg/day TMP; Info: part of multi-drug regimen
renal dosing
- [2-3x/wk regimen]
- renal impairment: not defined
- HD/PD: not defined
- [all other regimens]
- CrCl 15-30: decr. usual dose by 50%; CrCl <15: avoid use per pkg insert, Alt: 5-10 mg/kg/dose TMP q24h
- HD: avoid use; Alt: 5-10 mg/kg/dose TMP q24h, on dialysis days administer after dialysis; consider supplement if next maintenance dose not due right after dialysis; PD: avoid use; Alt: 5-10 mg/kg/dose TMP q24h; no supplement
hepatic dosing
- [see below]
- hepatic impairment: not defined, caution advised; Info: contraindicated if significant impairment
Contraindications / Cautions .
- hypersensitivity to drug or ingredient
- hypersensitivity to sulfonamides
- thrombocytopenia history, trimethoprim-associated
- thrombocytopenia history, sulfonamide-associated
- patients <2 mo (except PCP prophylaxis or toxoplasmosis prophylaxis use)
- breastfeeding of infants with G6PD deficiency
- hepatic impairment, significant
- anemia, megaloblastic
- folate deficiency
- G6PD deficiency
- thyroid dysfunction
- porphyria
- avoid: sun exposure
- avoid: UV light exposure, artificial
- caution: hypersensitivity to sulfites (INJ form)
- caution: elderly patients
- caution: hyperkalemia
- caution: hepatic impairment
- caution: renal impairment
- caution: bronchial asthma
- caution: malabsorption
- caution: malnutrition
- caution: PKU
- caution: allergies, severe
- caution: lupus erythematosus
- caution: alcohol use, chronic
- caution: antibiotic-associated colitis history, recent
Drug Interactions .
Overview
sulfamethoxazole
sulfonamide
- CYP2C9 inhibitor, weak
- affected by altered gastrointestinal motility
- alters GI flora
- hypoglycemic effects
- impairs immunomodulatory bacterial infective agent
- methemoglobinemia
- photosensitivity
- urine pH sensitive
trimethoprim
folate analog
- glucarpidase substrate
- CYP2C8 inhibitor, weak
- MATE1 inhibitor
- MATE2-K inhibitor
- OAT1 inhibitor
- OAT3 inhibitor
- OCT2 inhibitor
- P-gp inhibitor, weak
- affected by altered gastrointestinal motility
- alters GI flora
- hyperkalemia
- impairs immunomodulatory bacterial infective agent
- myelosuppressive effects
Contraindicated
- colchicine
- dofetilide
- lidocaine topical
- methenamine
- prilocaine topical
Avoid/Use Alternative
- amantadine
- amiloride
- aminolevulinic acid topical
- amiodarone
- apixaban
- BCG live intravesical
- benazepril
- bosentan
- bremelanotide
- captopril
- celecoxib
- chloramphenicol
- chloroprocaine
- chlorothiazide
- chlorthalidone
- cholera vaccine, live
- cladribine oral
- crizotinib
- cyclosporine
- dabigatran
- deferiprone
- diclofenac
- enalapril
- enalaprilat
- ensartinib
- fecal microbiota, live
- fexinidazole
- fluvastatin
- fosinopril
- ganciclovir
- glucarpidase
- hydrochlorothiazide
- indapamide
- indomethacin
- leucovorin
- lisinopril
- losartan
- methadone
- methotrexate
- metolazone
- moexipril
- neratinib
- olmesartan medoxomil
- pemetrexed
- perindopril
- pindolol
- porfimer
- potassium chloride
- potassium phosphate
- pralsetinib
- pramipexole
- primaquine
- pyrimethamine
- quinapril
- radium Ra 223 dichloride
- ramipril
- relugolix
- repotrectinib
- rivaroxaban
- ropeginterferon alfa-2b
- sepiapterin
- sirolimus albumin-bound
- sulbactam
- tacrolimus
- topotecan
- torsemide
- trandolapril
- tretinoin topical
- typhoid vaccine, live
- valganciclovir
- valsartan
- venetoclax
Monitor/Modify Tx
- abemaciclib
- acalabrutinib
- ado-trastuzumab emtansine
- afamitresgene autoleucel
- afatinib
- aficamten
- albendazole
- aldesleukin
- alemtuzumab
- aliskiren
- allopurinol
- anti-thymocyte globulin
- arsenic trioxide
- asciminib
- atidarsagene autotemcel
- atorvastatin
- auranofin
- axicabtagene ciloleucel
- azacitidine
- azathioprine
- balsalazide
- baricitinib
- belantamab mafodotin
- belinostat
- bendamustine
- benznidazole
- betibeglogene autotemcel
- bevacizumab
- bexarotene
- blinatumomab
- bortezomib
- bosutinib
- brentuximab vedotin
- brexucabtagene autoleucel
- busulfan
- cabazitaxel
- candesartan cilexetil
- capecitabine
- carboplatin
- carfilzomib
- carmustine
- chlorambucil
- cidofovir
- ciltacabtagene autoleucel
- ciprofloxacin
- cisplatin
- cladribine injection
- clofarabine
- clozapine
- copanlisib
- copper histidinate
- cyclophosphamide
- cytarabine
- dacarbazine
- dactinomycin
- dapsone
- daratumumab
- dasatinib
- daunorubicin
- decitabine
- deferasirox
- deuruxolitinib
- dexrazoxane
- diclofenac topical
- diflunisal
- digoxin
- dinutuximab
- docetaxel
- dostarlimab
- doxorubicin
- drospirenone (contraceptive)
- drospirenone (hormone replacement)
- duvelisib
- edoxaban
- eflornithine
- elivaldogene autotemcel
- elranatamab
- enfortumab vedotin
- entrectinib
- epcoritamab
- epirubicin
- eplerenone
- eribulin
- etodolac
- etoposide
- etuvetidigene autotemcel
- everolimus
- exagamglogene autotemcel
- exenatide
- fam-trastuzumab deruxtecan
- fedratinib
- fenoprofen
- finerenone
- floxuridine
- flucytosine
- fludarabine
- fluorouracil
- fluphenazine
- flurbiprofen
- foscarnet
- fosfomycin injection
- fosphenytoin
- fostamatinib
- furosemide
- gemcitabine
- gemtuzumab ozogamicin
- givinostat
- glasdegib
- glimepiride
- glipizide
- glofitamab
- glyburide
- heparin
- hydroxychloroquine
- hydroxyurea
- ibritumomab tiuxetan
- ibrutinib
- ibuprofen
- idarubicin
- idecabtagene vicleucel
- idelalisib
- ifosfamide
- imatinib
- imetelstat
- inotuzumab ozogamicin
- insulin
- interferon beta 1a
- interferon beta 1b
- interferon gamma 1b
- irbesartan
- irinotecan
- isatuximab
- ivosidenib
- ixabepilone
- ketoprofen
- ketorolac
- landiolol
- leflunomide
- lenalidomide
- lifileucel
- linezolid
- linvoseltamab
- lisocabtagene maraleucel
- lixisenatide
- lomustine
- lonafarnib
- loncastuximab tesirine
- lovotibeglogene autotemcel
- lurbinectedin
- lutetium Lu 177 dotatate
- lutetium Lu 177 vipivotide tetraxetan
- lymphocyte immune globulin, anti-thymocyte globulin
- mavorixafor
- meclofenamate
- mefenamic acid
- meloxicam
- melphalan
- mercaptopurine
- mesalamine
- mesalamine rectal
- metformin
- midostaurin
- mitomycin
- mitotane
- mitoxantrone
- mogamulizumab
- momelotinib
- morphine
- mosunetuzumab
- mycophenolate mofetil
- mycophenolic acid
- nabumetone
- naproxen
- nateglinide
- nelarabine
- nilotinib
- niraparib
- nitric oxide
- nitrite
- obecabtagene autoleucel
- obinutuzumab
- ofatumumab
- olaparib
- olsalazine
- osimertinib
- oxaliplatin
- oxaprozin
- paclitaxel
- pacritinib
- palbociclib
- peginterferon alfa 2a
- peginterferon beta 1a
- penicillamine
- pentamidine
- pentostatin
- phenytoin
- piroxicam
- pirtobrutinib
- polatuzumab vedotin
- pomalidomide
- ponatinib
- potassium acid phosphate
- potassium bicarbonate
- potassium citrate
- potassium iodide
- pralatrexate
- pramlintide
- procainamide
- procarbazine
- proguanil
- quinidine (antiarrhythmic)
- quizartinib
- ranolazine
- repaglinide
- ribavirin
- ribociclib
- rifabutin
- rituximab
- romidepsin
- rosiglitazone
- rucaparib
- ruxolitinib
- ruxolitinib topical
- sacituzumab govitecan
- sapropterin
- sarilumab
- satralizumab
- selinexor
- sirolimus
- sparsentan
- spironolactone
- stiripentol
- streptozocin
- succimer
- sulfasalazine
- sulindac
- tafasitamab
- tagraxofusp
- talazoparib
- talquetamab
- tarlatamab
- tazemetostat
- teclistamab
- telmisartan
- temozolomide
- temsirolimus
- tenofovir alafenamide
- tenofovir disoproxil
- teplizumab
- teriflunomide
- thalidomide
- thioguanine
- thiotepa
- tisagenlecleucel
- tocilizumab
- tofacitinib
- tolmetin
- tolvaptan
- trabectedin
- trastuzumab
- treosulfan
- triamterene
- trifluridine
- ubrogepant
- upadacitinib
- vadadustat
- valproic acid
- vancomycin
- vinblastine
- vincristine
- vinorelbine
- voclosporin
- warfarin
- zanubrutinib
- zidovudine
- ziv-aflibercept
Caution Advised
- acitretin
- amitriptyline
- amoxapine
- articaine
- avibactam
- benzocaine topical
- bumetanide
- bupivacaine
- bupivacaine liposomal
- butamben
- carbamazepine
- cefaclor
- cefuroxime axetil
- cefuroxime sodium
- cephalexin
- clomipramine
- dalfampridine
- dapsone topical
- darolutamide
- desipramine
- dichlorphenamide
- doxepin
- dulaglutide
- glecaprevir
- imipramine
- lactulose
- lamotrigine
- lidocaine
- liraglutide
- memantine
- mepivacaine
- meropenem
- methoxsalen
- metoclopramide
- naldemedine
- nitrofurantoin
- nitroglycerin
- nitroprusside
- nortriptyline
- pibrentasvir
- probenecid
- procaine
- protriptyline
- rasburicase
- resorcinol topical
- rifampin
- ropivacaine
- seladelpar
- sodium picosulfate
- sulfadiazine
- sulopenem
- tafenoquine
- tazobactam
- tetracaine
- tirzepatide
- trimipramine
- vaborbactam
- verteporfin
Adverse Reactions .
Serious Reactions
- Stevens-Johnson syndrome
- toxic epidermal necrolysis
- drug reaction with eosinophilia and systemic symptoms
- acute generalized exanthematous pustulosis
- hemophagocytic lymphohistiocytosis
- acute febrile neutrophilic dermatosis
- hepatic necrosis, fulminant
- agranulocytosis
- aplastic anemia
- hemolytic anemia
- blood dyscrasia
- thrombocytopenia
- hypersensitivity reaction
- anaphylaxis
- photosensitivity
- hepatotoxicity
- pancreatitis
- interstitial nephritis
- renal impairment
- renal failure
- pulmonary infiltrates
- myelosuppression
- methemoglobinemia
- hyperkalemia
- hyponatremia
- aseptic meningitis
- seizures
- lupus erythematosus
- hypoglycemia
- C. difficile-associated diarrhea
- rhabdomyolysis
- kernicterus (neonates)
- crystalluria
Common Reactions
- nausea
- vomiting
- anorexia
- rash
- urticaria
- hypersensitivity reaction
- photosensitivity
- diarrhea
- dizziness
- dyspepsia
- headache
- lethargy
- infusion reaction (INJ form)
Safety/Monitoring .
Monitoring Parameters
BUN/Cr at baseline, then periodically; CBC frequently; electrolytes frequently, especially K if renal impairment, concomitant drugs known to cause hyperkalemia, or potassium metabolism disorder; urinalysis
Look/Sound-Alike Drug Names
Bactrim DS confused with: Anaprox DS; Bancap HC
trimethoprim/sulfamethoxazole confused with: sulfasalazine
Pregnancy/Lactation .
Pregnancy
Clinical Summary
sulfamethoxazole: weigh risk/benefit during pregnancy, especially in 3rd trimester; risk of kernicterus near-term based on human data
trimethoprim: weigh risk/benefit during pregnancy, especially in 1st trimester; possible risk of spontaneous abortion based on limited human data; possible risk of congenital neural tube and cardiovascular defects based on conflicting human data and drug's mechanism of action
Lactation
Clinical Summary
sulfamethoxazole: avoid use while breastfeeding infant with G6PD deficiency, otherwise weigh risk/benefit while breastfeeding; possible risk of poor infant feeding based on limited human data; theoretical risk of hyperbilirubinemia in high-risk infants based on drug's mechanism of action; no human data available to assess effects on milk production
trimethoprim: may use while breastfeeding; no known risk of infant harm based on limited human data; no human data available to assess effects on milk production
Pharmacology .
Metabolism: for sulfamethoxazole: liver; CYP450: none; for trimethoprim: liver minimally; CYP450: unknown
Excretion: for sulfamethoxazole: urine (20-40% unchanged); Half-life: 6-12h, 20-50h (renal failure); for trimethoprim: urine primarily (primarily unchanged), feces 4%; Half-life: 8-10h, 20-50h (anuria)
Subclass: Antiparasitics ; Folate Antagonists, Antimicrobial ; Pneumocystis Pneumonia (PCP) ; Sulfonamides
Mechanism of Action
for sulfamethoxazole: competes with para-aminobenzoic acid (PABA), inhibiting folic acid synthesis; for trimethoprim: selectively inhibits dihydrofolate reductase
Formulary .
No Formulary Selected
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