About trimethoprim bp + sulphamethoxazole bp
Sulfonamide antibiotic combination
Used for
- Treats certain bacterial urinary tract infections
- Treats some respiratory and ear infections
- Treats and prevents Pneumocystis pneumonia
- Treats some gastrointestinal bacterial infections
Usual adult dose
Commonly one tablet twice daily for uncomplicated infections; dose and duration vary by infection.
Usual dose in children
Children’s doses are based on body weight and infection; specialist dosing is used for Pneumocystis pneumonia.
Common side effects
- Nausea, vomiting, or loss of appetite
- Skin rash and itching
- Diarrhoea
- Increased sensitivity to sunlight
Important warnings
- Rarely causes severe skin reactions or blood disorders.
- Avoid with sulfonamide allergy or severe liver or kidney disease.
- Kidney impairment may require dose adjustment and monitoring.
- Seek urgent care for blistering rash, breathing difficulty, or unusual bruising.
Pregnancy
Use only when clearly needed; folic acid supplementation may be important, especially early in pregnancy. Avoid near delivery where possible.
Breastfeeding
Usually compatible for healthy, full-term infants, but avoid or seek specialist advice for premature, jaundiced, ill, or G6PD-deficient infants.
Interactions
- Warfarin: increased bleeding risk; monitoring may be needed.
- Methotrexate: increased risk of bone marrow toxicity.
- ACE inhibitors or spironolactone: increased potassium risk.
- Phenytoin: may increase phenytoin effects.
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 It may be incomplete or out of date.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.