KATIE M. GREENLEENEW ORAL ANTICOAGULANTS New Oral Anticoagulants

The risk of bleeding, narrow therapeutic index, and need for routine monitoring make oral anticoagulation with warfarin a less than ideal oral anticoagulant. Intravenous therapies suchasheparinarenot orally bioavailable andhaveanarrow therapeutic index and high risk of bleeding. New oral antico-agulants currently under investigation may have more ideal characteristics for long-termadministration.Themechanism of thrombogenesis, limitations of current therapy, and new investigational oral anticoagulants are discussed. KEY WORDS: oral anticoagulation, heparin, direct thrombin inhibitor, warfarin, ximelagatran. MORBIDITY AND MORTALITY associated withan arterial or venous thrombotic event is ex-tremely high. In 1999, there were 529,659 deaths caused by coronary heart disease and 167,366 caused by stroke.1 Anticoagulants are used for the prevention and treatment of cardioembolic events as well as for ve