Drug interactions
Febuxostat is contraindicated with concomitant use of theophylline and chemotherapeutic agents, namely azathioprine and 6-mercaptopurine, because it could increase blood plasma concentrations of these drugs and thereby their toxicity. Pharmacology
Mechanism of action
Febuxostat is a non-purine-selective inhibitor of xanthine oxidase. It works by non-competitively blocking the molybdenum pterin center, which is the active site of xanthine oxidase. Xanthine oxidase is needed to oxidize successively hypoxanthine and xanthine to uric acid. Thus, febuxostat inhibits xanthine oxidase, thereby reducing production of uric acid. Febuxostat inhibits both the oxidized and the reduced forms of xanthine oxidase by virtue of its tight binding to the molybdenum pterin site. Pharmacokinetics
After oral intake, at least 84% of the febuxostat dose is absorbed in the gut, and highest blood plasma concentrations are reached after 60 to 90 minutes. When taken together with a fatty meal, febuxostat reaches lower concentrations in the body; but this is not considered clinically relevant. When in the bloodstream, 99.2% of the substance is bound to the plasma protein albumin, and 82–91% of the active metabolites are bound to plasma proteins. Febuxostat has three active metabolites in humans, which are formed mainly by a number of cytochrome P450 liver enzymes (CYP1A1, 1A2, 2C8, 2C9). One of them is a dicarboxylic acid, the other two are hydroxylated derivatives. These, as well as the original drug, are further glucuronidated, mainly by the enzymes UGT1A1, 1A8, and 1A9.
Febuxostat, sold under the brand names Uloric and Adenuric among others, is a medication used long-term to treat gout due to high uric acid levels. It is generally recommended only for people who cannot take allopurinol. When initially started, medications such as NSAIDs are often recommended to prevent gout flares. It is taken by mouth.Common side effects include liver problems, nausea, joint pain, and a rash. Serious side effects include an increased risk of death as compared with allopurinol, Stevens–Johnson syndrome, and anaphylaxis. Use is not recommended during pregnancy or breastfeeding. It inhibits xanthine oxidase, thus reducing production of uric acid in the body.Febuxostat was approved for medical use in the European Union in 2008 and in the United States in 2009. A generic version was approved in 2019 and is available as of 2020. Medical uses
Febuxostat is used to treat chronic gout and hyperuricemia. Febuxostat is typically recommended only for people who cannot tolerate allopurinol. National Institute for Health and Clinical Excellence concluded that febuxostat is more effective than standard doses of allopurinol, but not more effective than higher doses of allopurinol. Febuxostat is in the US pregnancy category C; there are no adequate and well-controlled studies in pregnant women.