4-Factor Prothrombin Complex Concentrate for Urgent Reversal of Vitamin K Antagonists in Patients with Major Bleeding
Vitamin K antagonists (VKA), such as warfarin, are widely used for prevention and treatment of arterial and venous thrombosis. Although oral or intravenous vitamin K and fresh frozen plasma are often used to reverse the anticoagulant effects of warfarin in patients who are bleeding, this approach has important limitations. Restoration of hemostasis with vitamin K relies on the hepatic synthesis of vitamin K-dependent procoagulant proteins -- factors II (prothrombin), VII, IX and X -- a process that takes more than 6 hours. Fresh frozen plasma provides an immediate source of functional vitamin K-dependent clotting proteins, but large volumes are often required to normalize the international normalized ratio (INR). This can be problematic because it takes time to blood type-match, thaw and infuse fresh frozen plasma, and the large volumes can lead to fluid overload, particularly in patients with compromised cardiac or renal function.
- Received August 5, 2013.
- Accepted August 7, 2013.