Brave new world: the current and future use of novel anticoagulants.

Advances in antithrombotic therapy began when traditional anticoagulant agents such as heparin and the vitamin K antagonists like Coumadin became commercially available in the 1940s and 1950s. Inherent limitations of these compounds, including the need for monitoring and multiple food and drug interactions (with coumadin), spurred the development of newer parenteral compounds like low molecular weight heparin, the pentasaccharide fondaparinux, and direct thrombin inhibitors such as hirudin, argatroban and bivalirudin with advantages over traditional compounds. Despite the failure of the first oral anticoagulant in 50 years--the direct thrombin inhibitor ximelagatran--due to issues with liver toxicity, new oral agents such as the Factor Xa inhibitors rivaroxaban, apixaban, YM-150, and DU-176b and oral direct thrombin inhibitors such as dabigatran are in advanced stages of development, with dabigatran and rivaroxaban now approved for use outside of the United States for thromboprophylaxis in the setting of orthopedic surgery. These and other novel agents have the potential to greatly expand our armamentarium to treat thromboembolic disease, with more targeted approaches to specific procoagulant complexes, a predictable anticoagulant response that does not require monitoring, and use in both acute and long-term treatment settings.