Allopurinol 300mg

Indication

Allopurinol is a xanthine oxidase inhibitor used to reduce hyperuricaemia associated with gout, uric acid nephrolithiasis, and secondary hyperuricaemia caused by malignant disease or its treatment.

Ingredients

• Allopurinol 300 mg

Direction

Adults: 100–300 mg once daily initially, taken after meals with plenty of fluid. Maintenance dose adjusted to serum uric acid level, typically 200–600 mg daily. Maximum dose: 900 mg/day. Reduce dose in renal impairment.

Side effects

• Uncommon: skin rash
• nausea
• vomiting
• diarrhoea.
• Rare: severe hypersensitivity syndrome and severe skin reactions (stop immediately).
• Rare: hepatotoxicity.
• Uncommon: headache
• drowsiness.
• Rare: blood disorders (agranulocytosis
• thrombocytopenia).

Precautions

• Do not start during an acute gout attack
• ensure attack has fully subsided.
• Stop immediately if skin rash develops — risk of severe cutaneous adverse reactions (Stevens
• Johnson syndrome
• TEN).
• Higher risk of severe skin reactions in patients with HLA
• B*5801 allele (Han Chinese
• Thai
• Korean) — genetic testing recommended.
• Reduce dose in renal impairment.
• Use with caution in hepatic impairment.
• Ensure adequate fluid intake (at least 2 litres/day).
• Reduce azathioprine or mercaptopurine dose to one
• quarter if co
• administered.
• May enhance anticoagulant effect of warfarin.