Co-trimoxazole
Also sold as: Septran, Bactrim
Usual adult dose
Usual adult dose: 960 mg (800/160 mg) twice a day, usually for 3 to 14 days depending on the infection. Drink plenty of water. Children: dose by weight — ask your doctor or pharmacist.
Your doctor may give you a different dose. Children's doses depend on weight.
Side effects
Common
- nausea
- vomiting
- loss of appetite
- skin rash
Serious — get help
Stop taking it and see a doctor straight away if you notice:
- severe skin rash with blisters or peeling
- sore throat with fever or unusual bruising
- yellow eyes or skin
- severe allergic reaction
Do not take it, or take care, if
- Allergy to sulfonamide (sulfa) medicines
- Pregnancy (only if a doctor decides it is needed)
- Newborn babies under 6 weeks
- Severe liver or kidney disease
- G6PD deficiency
Interactions
Medicines that can react with this one.
Serious4 medicinesDo not take these together unless your doctor says so.
- Methotrexate
Both block folate; together they can cause serious bone marrow damage.
- Spironolactone
Can raise blood potassium to dangerous levels, especially in older people.
- Sulfadoxine + Pyrimethamine
Both are sulfa and folate-blocking medicines; together they raise the risk of severe skin and blood reactions.
- Warfarin
Strongly raises the effect of warfarin and the risk of bleeding; INR must be checked.
Moderate5 medicinesTake together only with care. Ask your doctor or pharmacist.
- Azathioprine
Together they increase the risk of low blood counts.
- Glibenclamide
Co-trimoxazole can increase the sugar-lowering effect and cause low blood sugar.
- Gliclazide
Co-trimoxazole can increase the risk of low blood sugar.
- Glimepiride
Co-trimoxazole can increase the risk of low blood sugar.