New Anticoagulants Promising but Problematic

Cardiology News Digital Network: By: MARK S. LESNEY, March 05, 2012.

Because anticoagulation is a balancing act between the prevention of clots and the risk of major bleeds, tremendous efforts have been made to find the safest, most effective drugs possible. The foundations of anticoagulant therapy – warfarin (taken orally) and heparin (taken intravenously) – are being shaken by an onslaught of the newer oral factor Xa inhibitors and a direct thrombin inhibitor.

Two of these inhibitors are currently approved by the Food and Drug Administration, with others poised for approval.

Warfarin, the current standard for outpatient oral anticoagulant therapy, leaves a lot to be desired. The need for International Normalized Ratio (INR) monitoring has made patient compliance a significant problem, as some patients must travel routinely to their doctor’s office or warfarin clinics for blood monitoring (although there has been some movement toward putting the INR-monitoring process into patient hands). Even for compliant patients, reaching and maintaining an appropriate INR can be difficult, and warfarin carries the risk of a major bleed, especially among fragile elderly patients.

But is a move from warfarin to the new drugs premature? Many concerns remain, including potential difficulties with surgery in patients taking these agents.

The two FDA-approved drugs are rivaroxaban (Xarelto, marketed by Janssen Pharmaceuticals), which is a direct factor Xa inhibitor, and dabigatran (Pradaxa, marketed by Boehringer Ingelheim), a direct thrombin inhibitor.* Read More