Drugs affecting coagulation

For more than half a century, heparin and vitamin K antagonists have defined anticoagulant therapy in both the short-term and long-term management of thrombotic diseases. However, the limitations of these traditional anticoagulants have prompted the development of new drugs. In the past 15 years new agents with improved safety profile and greater ease of use that target almost every step of the coagulation cascade have been developed. These include factor Xa inhibitors and direct thrombin inhibitors. The mechanism of action of these new anticoagulants and also the 'older' agents are reviewed in this article.