About allopurinol
Xanthine oxidase inhibitor
Used for
- Long-term prevention of gout and uric acid kidney stones
- Lowering uric acid in certain cancers or inherited conditions
Usual adult dose
Gout: usually start at 100 mg once daily and adjust gradually; typical maintenance is 200–600 mg daily. Kidney impairment requires lower dosing.
Usual dose in children
Cancer-related high uric acid: usually 10 mg/kg daily in three divided doses; specialist dosing is required.
Common side effects
- Rash
- Nausea or diarrhea
- Raised liver enzymes
- Drowsiness
Important warnings
- Stop and seek urgent care for a severe rash, blistering, facial swelling, or breathing difficulty.
- Rarely causes serious hypersensitivity, especially with kidney disease or certain genetic risk factors.
- Drink enough fluids; dose may need adjustment in kidney or liver disease.
- It does not treat an acute gout attack.
Pregnancy
Use when clearly needed; untreated high uric acid conditions may also pose risks. A clinician should weigh benefits and risks.
Breastfeeding
Small amounts may enter breast milk. Use requires weighing benefits and risks with a healthcare professional.
Interactions
- Azathioprine or mercaptopurine: dangerously increased effects; major dose reduction and monitoring are needed.
- Warfarin: may increase anticoagulant effect; monitoring may be needed.
- Theophylline: levels may rise, especially with higher allopurinol doses.
- Ampicillin or amoxicillin: increased risk of rash.
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 It may be incomplete or out of date.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.