Rivaroxaban a direct specific competitive factor Xa inhibitor

Rivaroxaban a direct specific competitive factor Xa inhibitor

Rivaroxaban is direct, specific, competitive factor Xa inhibitor and it has a half life of five to thirteen hours. One third of the drug is cleared directly by the kidneys while two third is metabolized by the cytochrome P 450 enzymes. Rivaroxaban is administered once daily by oral route. There is no need for therapeutic monitoring like warfarin. Rivaroxaban was compared with warfarin in a double blind randomized control trial known as ROCKET-AF [1]. Warfarin was maintained at a target INR (international normalized ratio of prothrombin time) between 2 to 3. Around fourteen thousand patients with nonvalvar atrial fibrillation and additional risk factors (two or three of the following: congestive heart failure, hypertension, age seventy five or above, diabetes mellitus) or with a history of stroke, TIA (transient ischemic attack) or systemic embolism were included in the study. The dosage of rivaroxaban was 20 milligrams daily (15 milligrams daily for those with creatinine clearance between 30 and 49 milli liters per minute). Patients were monitored monthly and standard care guidelines were followed. The primary endpoint was stroke or non central nervous system systemic embolism. The cumulative event rate was 1.71 percent with rivaroxaban and 2.16 percent with warfarin with P value or non inferiority of <0.001. The investigators found that rivaroxaban is not inferior to warfarin for prevention of stroke and non central nervous system systemic embolism. Rivaroxaban was superior to warfarin while patients were taking the study drug and the bleeding rates as well as other adverse event rates were similar. There was less intracranial hemorrhage and fatal bleeding with rivaroxaban. Finally they concluded that rivaroxaban is an alternative to warfarin for those with moderate or high risk for stroke in atrial fibrillation.

Reference

  1. Manesh R Patel, Kenneth W Mahaffey, Jyotsna Garg, Guohua Pan, Daniel E Singer, Werner Hacke, Günter Breithardt, Jonathan L Halperin, Graeme J Hankey, Jonathan P Piccini, Richard C Becker, Christopher C Nessel, John F Paolini, Scott D Berkowitz, Keith A A Fox, Robert M Califf, ROCKET AF Investigators. Rivaroxaban Versus Warfarin in Nonvalvular Atrial Fibrillation. N Engl J Med. 2011 Sep 8;365(10):883-91.