Febuxostat is a xanthine oxidase (XO) inhibitor that is used to treat hyperuricemia. The main side effects can be abnormal liver function, allergic reactions and other side effects. 1. Action Febuxostat is a xanthine oxidase inhibitor that reduces serum uric acid to achieve efficacy. It is used for the prevention of gout. However, it is not recommended for hyperuricemia without clinical symptoms. 2.Side effects (1) Hepatobiliary system abnormalities: e.g. gallstones/cholecystitis, hepatic steatosis, hepatitis, hepatomegaly. (2) Allergic reactions: Patients taking Febutasib are usually allergic to the ingredients in the drug, which may lead to skin rashes. If you need to take this drug, you need to use it under the guidance of a physician, and avoid blind use of medication in order to prevent the condition from deteriorating.