Febuxostat is a potent, selective, non-purine xanthine oxidase inhibitor used for the long-term management of hyperuricemia in patients with gout. It is a second-line agent after allopurinol intolerance or failure. Unlike allopurinol, it is not a purine analogue and does not require dose adjustment in mild-to-moderate renal impairment, making it a significant option in the Indian context where renal comorbidities are common.
Adult: Recommended starting dose is 20mg or 40mg once daily. The 20mg dose is recommended for patients with mild hyperuricemia or as a starting dose to assess tolerability. Dose may be increased to 40mg or 80mg daily if target sUA (<6 mg/dL) is not achieved after 2-4 weeks.
Note: Administer orally once daily, with or without food. Tablet should be swallowed whole with a glass of water. Consistent daily timing is recommended. Prophylaxis for gout flares with NSAID or colchicine should be initiated concurrently and continued for up to 6 months.
Febuxostat is a non-purine selective inhibitor of xanthine oxidase (XO), the enzyme responsible for the conversion of hypoxanthine to xanthine and xanthine to uric acid. By inhibiting XO, it reduces the production of uric acid, thereby lowering serum urate concentrations.
Pregnancy: Category C. Animal studies have shown fetal toxicity. There are no adequate and well-controlled studies in pregnant women. Use only if the potential benefit justifies the potential risk to the fetus. Not recommended for use during pregnancy.
Driving: Febuxostat may cause dizziness and fatigue in some patients. Patients should be cautioned about operating machinery or driving until they are certain the medication does not affect them adversely.
| Azathioprine | Increased levels/toxicity of azathioprine due to xanthine oxidase inhibition | Contraindicated |
| Mercaptopurine (6-MP) | Increased levels/toxicity of mercaptopurine due to xanthine oxidase inhibition | Contraindicated |
| Theophylline | Increased theophylline levels, risk of toxicity | Contraindicated |
| Didanosine | Potential increased toxicity; avoid concomitant use | Major |
| NSAIDs (e.g., Naproxen, Diclofenac) | Increased risk of NSAID-related adverse effects; used together for gout flare prophylaxis | Moderate |
| Colchicine | No significant PK interaction, but used together therapeutically. Monitor for colchicine toxicity, especially in renal impairment. | Moderate |
| Warfarin | Potential for increased INR; monitor INR closely when initiating or discontinuing febuxostat. | Moderate |