Recombinant FVIIa in the Treatment of Warfarin Bleeding

Patients receiving oral anticoagulant treatment have abnormally low levels of functional vitamin K-dependent coagulation proteins and consequently a clear risk of hemorrhagic complications. The incidence of hemorrhages has been reported to be around 0.6-0.7% per month at a therapeutic International Normalized Ratio (INR) and the incidence of major hemorrhagic events is substantial. Therefore, the ability to reverse the anti-vitamin K effect is of utmost importance, and if an immediate reversal is necessary, plasma or prothrombin complex concentrates are used. As plasma-derived products carry the risk of transmission of blood-borne viruses and also of thromboembolic complications, it is desirable to test new potential tools for oral anticoagulant reversal. Recombinant factor VIIa (FVIIa) has been tested in rats and humans treated with antivitamin K drugs with seemingly good effect on hemostasis and laboratory parameters. Even if more data are needed before any definite conclusions can be drawn, the outlook so far seems promising.