Drug Interactions with Rivaroxaban following Total Joint Replacement Surgery

OBJECTIVE: To evaluate potential drug-drug interactions with rivaroxaban in patients undergoing total hip replacement (THR) and total knee replacement (TKR) surgeries. DATA SOURCES: PubMed; January 2009-April 2012 abstract databases of major congresses for hematology and cardiovascular medicine. STUDY SELECTION AND DATA EXTRACTION: Searches were performed using the key words rivaroxaban and drug interaction. Studies were included if they evaluated interactions with drugs that are commonly used in patients undergoing THR or TKR, based on our clinical experience. DATA SYNTHESIS: A Phase 1 study found that coadministration of rivaroxaban and the nonsteroidal antiinflammatory drug (NSAID) naproxen significantly increased bleeding time. However, in a retrospective analysis of 4 large trials evaluating rivaroxaban in patients undergoing THR or TKR, the difference between major and clinically relevant nonmajor bleeding was not significantly different between NSAID users and nonusers. In addition, proton pump inhibitors, which are frequently coadministered with NSAIDs to prevent gastrointestinal toxicity, have not been demonstrated to cause any appreciable changes in rivaroxaban pharmacokinetics or pharmacodynamics. A Phase 2 study that evaluated several doses and administration intervals of rivaroxaban in combination with aspirin or both aspirin and clopidogrel in patients with acute coronary syndrome found that clinically significant bleeding events occurred in patients receiving rivaroxaban 10 mg daily (the dose approved for the orthopedic indication). However, this risk was not great enough to end the trial early. CONCLUSIONS: Phase 1 drug-drug interaction studies in healthy humans provided little insight into the pharmacodynamic drug interactions between rivaroxaban and NSAIDs or antiplatelet agents. A pooled analysis of the RECORD (Regulation of Coagulation in Orthopedic Surgery to Prevent Deep Vein Thrombosis and Pulmonary Embolism) trials and data from other large trials provides clinical evidence that these agents can be coadministered with rivaroxaban, as long as proper monitoring is instituted.