A new era for oral anticoagulation? Old and new anticoagulant drugs.

The expanding demand for long-term antithrombotic therapy and the major limitations of the vitamin-K antagonists, namely their narrow therapeutic range, numerous drug interactions and need for laboratory monitoring, have stimulated the development of new antithrombotic agents. Direct thrombin inhibitors and factor Xa inhibitors are the new classes of orally available anticoagulants that are most advanced in development. Large clinical trials evaluate several compounds both in the primary and secondary prevention of venous thromboembolism and in the prevention of cardioembolism in patients with atrial fibrillation.