Rivaroxaban: a novel oral factor Xa inhibitor to prevent stroke in nonvalvular atrial fibrillation

Rivaroxaban is an oral, direct factor Xa inhibitor under review by FDA for stroke prevention in patients with atrial fibrillation. Atrial fibrillation is the most common arrhythmia in the United States and conveys a 5-fold increased risk for stroke. Vitamin K antagonists, such as warfarin, remain the recommended antithrombotic treatment in this patient population, but clinical use of warfarin is limited by the need for frequent monitoring, prevalent and significant drug and food interactions, and genetic variability. As a result, alternatives that are more straightforward to manage are needed. It is likely that rivaroxaban will be administered in once-daily dose and will not require routine laboratory monitoring. Drug interactions have been reported but are limited to cytochrome P450 3A4 and P-glycoprotein. The efficacy and safety of warfarin and rivaroxaban were studied in a phase 3 trial. Preliminary findings established rivaroxaban as noninferior to warfarin. In addition, bleeding outcomes were similar between rivaroxaban and warfarin. (Formulary. 2011;46:257-267.)