I had my hopes that ximelagatran would be the replacement for warfarin. That did not happen because of liver toxicity problems with the drug. Now several new drugs are traveling through the clinical trial pathways.Most of these are in a new class of anticoagulants known as Factor Xa inhibitors.
The medication leading the pack, in terms of being closest to approval, is rivaroxaban. Clinical trial results are found in the June 26,2008 issue of NEJM for the hip arthroplasty and total knee replacement studies. Both found fewer episodes of thrombosis in the rivaroxaban group and no statistical difference in bleeding when compared with enoxaparin. The liver toxicity that killed ximilagatran so far has not been a problem. Another Factor Xa inhibitor,apixaban, is in trials as is a direct thrombin inhibitor,dabigatran.
If and when the clinical trial(s) comparying "riva" with warfarin in chronic atrial fibrillation demonstrates similar good results we may finally have a new oral anticoagulant than does not require frequent blood test monitoring and may be free of much of the vexing vagaries of trying to get the dose of warfarin right and keeping it there.