Lipid-Lowering Therapy and Risk for Bleeding Among Warfarin Users

Medications that are metabolized by CYP3A4 or CYP2C9 can diminish clearance of warfarin and, secondarily, can amplify bleeding risk. Some lipid-lowering agents, including simvastatin, fluvastatin, atorvastatin, gemfibrozil, and fenofibrate, interact with CYP3A4 or CYP2C9, but pravastatin does not. In a case-control study based on Medicaid data from several states, researchers assessed whether risk for hospitalization for gastrointestinal bleeding was elevated among chronic warfarin users after initiation of lipid-lowering therapy; 12,000 hospitalized warfarin users were compared with 600,000 who were not hospitalized.

During the 30 days after filling initial prescriptions for atorvastatin, simvastatin, or gemfibrozil, chronic warfarin users …