About co trimoxazole
Sulfonamide-antibiotic combination
Used for
- Treats certain bacterial infections, including urinary, respiratory, and ear infections
- Treats or prevents Pneumocystis pneumonia in people at risk
Usual adult dose
Commonly 160/800 mg by mouth every 12 hours for many infections; dose depends on infection and kidney function.
Usual dose in children
For many infections, 8 mg/kg trimethoprim plus 40 mg/kg sulfamethoxazole daily, divided every 12 hours; clinician-directed.
Common side effects
- Nausea, vomiting, or reduced appetite
- Rash or itching
- Increased potassium or changes in blood counts
- Severe skin reactions, rarely
Important warnings
- Avoid with sulfonamide or trimethoprim allergy; serious reactions can occur.
- Seek urgent care for blistering rash, facial swelling, or breathing difficulty.
- Kidney disease, folate deficiency, and older age may increase risks.
- Not suitable for infants under two months.
Pregnancy
May affect folate metabolism and newborn bilirubin; use only when a clinician considers it necessary, especially avoid near delivery.
Breastfeeding
Generally compatible for healthy, full-term infants after the newborn period; avoid if infant is premature, jaundiced, ill, or G6PD-deficient.
Interactions
- Warfarin: may increase bleeding risk.
- Methotrexate: may increase toxicity.
- ACE inhibitors, ARBs, or spironolactone: may raise potassium.
- Phenytoin: may increase phenytoin levels.
AI-generated from general medical knowledge, not from this product's official leaflet. It may be incomplete or out of date. Not medical advice — ask a pharmacist or doctor before making any decision.