Background: Warfarin is commonly used in long-term anticoagulation and has a narrow therapeutic index. Dosing is dependent on intrinsic patient variables including cytochrome P450 2C9 (CYP2C9) and VKORC1 polymorphisms. High protein binding and CYP-dependent clearance mechanisms of NSAIDs also affect warfarin serum levels. This study investigates the observed pharmacologic interaction of concurrent NSAID and warfarin [...]