Adult and pediatric> 40 kg:
Usaual dose:PO, 2 tab.(or 20ml) q12h.
Chronic bronchitis: PO, 2 tab.(or 20ml) q12h for 14 days
Granuloma inguinale: PO, 2 tab.(or 20ml) BID for at least 3 weeks
PCP, prophylaxis: PO, 2 tab.(or 20ml) QD; alternative regimens, 2 tab. 3 times/wk or 1 tab.(or 10ml) QD.
PCP, treatment: PO, TMP 15-20 mg/kg/d divided every 6 hr for 14-21 days
Shigellosis; Travelers' diarrhea: PO, 2 tab.(or 20ml) q12h for 5 days
Toxoplasmic encephalitis, prophylaxis: PO,1 tab.(or 10ml)QD.
UTI: PO, 2 tab.(or 20ml) q12h for 10-14 days
Pediatric
Usual dose:
Infants3 2 mo,< 40 kg: PO, SMX 20-30 mg/kg and TMP 4-6 mg/kg q12h.
Otitis media: Pediatric3 2 mo, PO, 8 mg/kg TMP component/day divided every 12 hr for 10 days
PCP, prophylaxis: Peditric3 1 mo, PO, 150 mg/m2 TMP component/day in 2 divided doses 3 times/wk on consecutive days; alternative regimens, 150 mg/m2 TMP component QD 3 times/wk on consecutive days or 150 mg/m2 TMP component/day in 2 divided doses every day or 3 times/wk on alternate days
PCP, treatment: Pediatric 3 2 mo, PO, 15-20 mg/kg TMP component/day divided every 6 hr for 14-21 days
Toxoplasmic encephalitis, prophylaxis:Pediatric 3 2 mo, PO, 150 mg/m2 TMP component/day in 2 divided doses

hypersensitivity to sulfonamides or trimethoprim;
infants less than 2 months(pneumocystis carinii pneumonia prophylaxis can begin at 1 month of age);
pregnancy at term;
nursing mothers;megaloblastic anemia due to folate deficiency.