Xanthine Oxidase Inhibitors
Suggested Use
Allopurinol is used to treat:
- Gout: Reduces uric acid levels to prevent gout attacks.
- Kidney Stones: Prevents the formation of uric acid stones.
- Certain Enzyme Disorders: Helps manage conditions like Lesch-Nyhan syndrome.
- Cancer Treatment: Prevents uric acid nephropathy during chemotherapy.
Dosage:
The typical dosage for adults is:
- Mild conditions: 100-200 mg daily.
- Moderate conditions: 300-600 mg daily.
- Severe conditions: Up to 900 mg daily. It’s important to start with a low dose and gradually increase it to minimize side effects.
Warning
Hypersensitivity Reactions: Discontinue immediately if symptoms such as rash, fever, or other allergic reactions occur. Severe reactions like Stevens-Johnson syndrome and toxic epidermal necrolysis are rare but possible.
- Kidney Function: Use cautiously in patients with impaired renal function; dose adjustments are necessary.
- Hepatic Function: Monitor liver enzymes during prolonged use, especially in patients with pre-existing liver conditions.
- Initial Gout Flares: May provoke acute gout flares at the start of treatment; consider prophylactic use of NSAIDs or colchicine.
- Hydration: Maintain adequate hydration to reduce the risk of kidney stones and enhance uric acid excretion.
- Drug Interactions:
- May interact with azathioprine, mercaptopurine, and cyclophosphamide, requiring dose adjustments.
- Increased risk of skin reactions when used with ampicillin/amoxicillin.
- Potentiation of anticoagulants like warfarin is possible; monitor INR.
- Pregnancy and Lactation: Use only if the potential benefit outweighs the risk; consult a healthcare provider.
- Alcohol: Limit alcohol intake as it can increase uric acid levels and reduce treatment efficacy.
