Febuxostat: a selective xanthine-oxidase/xanthine-dehydrogenase inhibitor for the management of hyperuricemia in adults with gout.
BACKGROUND
Febuxostat, a nonpurine selective inhibitor of both the oxidized and reduced forms of xanthine oxidase, was approved in February 2009 by the US Food and Drug Administration for the management of hyperuricemia in adults with gout.


OBJECTIVE
The purpose of this review was to summarize available information about the clinical use of febuxostat, including its chemistry, pharmacology, pharmacokinetics, pharmacodynamics, clinical efficacy, and safety profile.


METHODS
A search of the medical literature using PubMed (1949-August 2009) and the Iowa Drug Information Service (1966-August 2009) was performed to identify all published articles about febuxostat. Key search terms included febuxostat, hyperuricemia, gout, TMX-67, and TEI-6720. Articles were limited to those published in English. Reference lists of the primary set of articles identified were reviewed for pertinent articles and scientific meeting abstracts not identified in the original search.


RESULTS
A total of 88 published articles (including 14 human studies) were identified in the original search. Review of the references of these 88 articles yielded 7 additional trials published in abstract form. Clinical trial data from this review were obtained from these 21 studies. Dose-dependent reductions from baseline in serum urate occur with febuxostat. Clinical trials found that 40 mg/d of febuxostat was noninferior to conventionally dosed allopurinol (300 mg/d) in the percentage of subjects achieving the primary end point of serum urate <6.0 mg/dL (45% for febuxostat vs 42% for allopurinol), whereas 80 mg/d of febuxostat was reported to be superior (67% vs 42%; P < 0.001). Febuxostat 40 and 80 mg/d appeared to be well tolerated in the populations studied, with adverse events mostly limited to liver enzyme elevations (6.6% and 4.6%, respectively), nausea (1.1% and 1.3%), arthralgias (1.1% and 0.7%), and rash (0.5% and 1.6%). Febuxostat does not require dosage adjustment in patients with mild to moderate renal impairment (creatinine clearance, 30-89 mL/min). Because of the risk of acute gout flares occurring when febuxostat treatment is initiated, concomitant therapy with colchicine or an NSAID for >or=8 weeks is recommended.


CONCLUSIONS
Febuxostat is the first agent marketed in the United States to treat hyperuricemia of gout since allopurinol was approved in 1964. In English-language published clinical trials, it was found to be noninferior to allopurinol and generally well tolerated.
Ernst
Michael E
ME
Department of Pharmacy Practice and Science, College of Pharmacy, University of Iowa, Iowa City, Iowa 52242, USA. michael-ernst@uiowa.edu
Fravel
Michelle A
MA
D000493:Allopurinol / Q000627:therapeutic use; D001711:Biotransformation; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D004791:Enzyme Inhibitors / Q000627:therapeutic use*; D000069465:Febuxostat; D006073:Gout / Q000150:complications / Q000188:drug therapy*; D006074:Gout Suppressants / Q000008:administration & dosage / Q000009:adverse effects / Q000493:pharmacokinetics / Q000627:therapeutic use*; D006207:Half-Life; D006801:Humans; D033461:Hyperuricemia / Q000150:complications / Q000188:drug therapy*; D013844:Thiazoles / Q000009:adverse effects / Q000493:pharmacokinetics / Q000627:therapeutic use*; D014018:Tissue Distribution; D014527:Uric Acid / Q000097:blood; D014968:Xanthine Dehydrogenase / Q000037:antagonists & inhibitors*; D014969:Xanthine Oxidase / Q000037:antagonists & inhibitors*
D004791:Enzyme Inhibitors; D006074:Gout Suppressants; D013844:Thiazoles; D000069465:Febuxostat; D014527:Uric Acid; D000493:Allopurinol; D014968:Xanthine Dehydrogenase; D014969:Xanthine Oxidase