Abstract
Antivitamin K agents are currently the only orally available anticoagulant compounds. During the past two decades, important research has focused on the discovery of a direct, orally active thrombin inhibitor. In 1991, DuP 714, a boro arginine derivative, was shown to possess anticoagulant activity in different animal species after oral administration. S 18326, structurally related to DuP 714, is a further potent thrombin inhibitor. Moreover, its improved selectivity profile, associated with potent anticoagulant and antithrombotic properties, favours potential development of this compound for venous, as well as arterial, thromboembolism.