Uxoric Drug Interactions

Drugs affecting hepatic microsomal or other enzymes: Drug interactions generally are not expected between febuxostat and inhibitors or inducers of particular enzyme isoforms.
Drugs metabolized by hepatic microsomal enzymes: Febuxostat does not inhibit CYP1A2, CYP2C9, CYP2C19, or CYP3A4, but is a weak inhibitor of CYP2D6. Febuxostat does not induce CYP1A2, CYP2B6, CYP2C9, CYP2C19, CYP3A4. Pharmacokinetic interactions are unlikely between febuxostat and substrates of these isoenzymes.
Despiramine: Effects of febuxostat on desipramine pharmacokinetics are not considered clinically important; dosage adjustment is not expected to be necessary.
Drugs metabolized by xanthine oxidase: Febuxostat is a xanthine oxidase inhibitor and may increase plasma concentrations of drugs metabolized by xanthine oxidase, resulting in toxicity.
Azathioprine and Mercaptopurine: Concomitant use of febuxostat with azathioprine and mercaptopurine is contraindicated since increased plasma concentrations of azathioprine and mercaptopurine have been reported when these drugs were administered concomitantly with allopurinol, another xanthine oxidase inhibitor. Drug interaction studies between febuxostat and azathioprine or mercaptopurine are not available.
Theophylline: Following concomitant administration of febuxostat (80 mg once daily) and theophylline in healthy individuals, peak plasma concentrations were not altered, thus theophylline dosage adjustments are not necessary when febuxostat and theophylline are used concomitantly.
Antacid: Pharmacokinetic interaction is unlikely.
Antineoplastic agents: Studies data are not available regarding safety of febuxostat in patients receiving antineoplastic agents.
Colchicine: Clinically important pharmacokinetic interaction is unlikely; dosage adjustment is not needed.
Hydrochlorothiazide: Clinically important pharmacokinetic interaction is unlikely; dosage adjustment is not needed.
Nonsteroidal Anti-inflammatory Agents (NSAIDs): Indomethacin: Clinically important pharmacokinetic interaction is unlikely; dosage adjustment is not needed.
Naproxen: Clinically important pharmacokinetic interaction is unlikely; dosage adjustment is not needed.
Warfarin: Pharmacokinetic interaction is unlikely; dosage adjustment is not needed.