xanthineoxidaseinhibitors
Xanthine oxidase inhibitors are a class of medications that reduce the production of uric acid by inhibiting the enzyme xanthine oxidase, which catalyzes the conversion of hypoxanthine to xanthine and xanthine to uric acid in purine metabolism. By decreasing uric acid synthesis, they lower serum urate levels and can help prevent gout flares and urate crystal deposition.
Two main agents are used clinically: allopurinol and febuxostat. Allopurinol is a structural analog of hypoxanthine;
Adverse effects include rash, gastrointestinal upset, and liver enzyme elevations; allopurinol can cause hypersensitivity reactions, including
Drug interactions: XO inhibitors can raise levels of thiopurines such as azathioprine and 6-mercaptopurine, so concomitant
They do not treat acute gout flares and are typically started after an acute flare has subsided.