Allopurinol
Also sold as: Zyloric
Usual adult dose
Usual adult dose: start with 100 mg once a day after food, increased slowly by your doctor (commonly 100 to 300 mg a day) based on uric acid levels. It is usually started once a gout attack has settled. Drink plenty of water.
Your doctor may give you a different dose. Children's doses depend on weight.
Side effects
Common
- skin rash
- nausea
- more gout attacks in the first months
Serious — get help
Stop taking it and see a doctor straight away if you notice:
- any rash with fever
- blisters
- peeling skin or mouth sores (stop and get help urgently)
- yellow eyes or skin
Do not take it, or take care, if
- Previous serious skin reaction to allopurinol
- Kidney disease (a lower dose is needed)
- Taking azathioprine (dangerous combination unless the doctor adjusts doses)
Interactions
Medicines that can react with this one.
Serious1 medicineDo not take these together unless your doctor says so.
- Azathioprine
Allopurinol greatly raises azathioprine levels and can cause severe bone marrow damage; the azathioprine dose must be cut sharply or avoided.
Moderate1 medicineTake together only with care. Ask your doctor or pharmacist.
- Warfarin
Allopurinol can increase the effect of warfarin; INR should be checked.
Minor2 medicinesUsually not a problem, but tell your doctor.
- Amoxicillin
Skin rash is more common when amoxicillin is taken with allopurinol.
- Ampicillin
Skin rash is more common when ampicillin is taken with allopurinol.