Objective To evaluate the US spontaneous reporting system of cardiac adverse events of febuxostat,analyze the risks and provide data for safe use of uric acid-lowering drugs.Methods Based on the FAERS database reports of cardiac adverse events of febuxostat from Q1 2004 to Q3 2021,the risk signals were evaluated.In a rat model of hyperuricemia,high dose(7.2 mg·kg-1)and low dose(3.6 mg·kg-1)groups of febuxostat were set up to observe the uric acid level,related cardiac indexes and histopathology in biochemical tests.Results A total of 5 001 adverse reaction reports and 15 989 adverse reactions were retrieved from the FAERS database for febuxostat,and 992 of the adverse reactions with cardiac relevance had 18 cardiac risk signals.Febuxostat cardiotoxicity was more common in males and usually occurred among those over 65.In animal experiments,a significant reduction in uric acid levels was observed in rats administered with febuxostat in a hyperuricemic state,indicating a good uric acid-lowering effect.Such cardiac indicators as AST,CK and cTn-Ⅰ increased,while LDH and CK-MB levels decreased.MASSON staining showed that the febuxostat groups appeared to have different degrees of fibrosis,with pronounced blue collagen deposition.Conclusion In the clinical use.of febuxostat for the treatment of hyperuricemia,cardiac risks ought to be considered to ensure rational use of febuxostat in different clinical populations.