Rivaroxaban is a highly selective direct factor Xa inhibitor, with oral bioavailability, that interrupts the intrinsic and extrinsic blood coagulation pathway, inhibiting both thrombin formation and development of thrombi.
Two phase III studies,1,2 involving over 4,500 patients undergoing elective hip replacement surgery and over 2,500 patients undergoing elective knee replacement surgery, compared the efficacy of rivaroxaban to enoxaparin for the prevention of venous thromboembolism.
The patients were given oral rivaroxaban 10mg once daily started six to eight hours after surgery, or subcutaneous enoxaparin 40mg given 12 hours before surgery and then 40mg once daily started six to eight hours after surgery.
In both studies, rivaroxaban was significantly more effective than enoxaparin in reducing total events of venous thromboembolism and all cause mortality.
The number of major bleeding episodes, the main safety outcome, was comparable for patients treated with rivaroxaban and enoxaparin.
1. Eriksson B, Borris L, Friedman R et al. Rivaroxaban versus enoxaparin for thromboprophylaxis after hip arthroplasty. NEJM 2008; 358: 2765-75.
2. Lassen M, Ageno W, Borris L et al. Rivaroxaban versus enoxaparin for thromboprophylaxis after total knee arthroplasty. NEJM 2008; 358: 2776-86.
Further information: Bayer HealthCare