Development of new anticoagulants: present and future.

Anticoagulant drugs are the most frequently hospital-prescribed compounds in many countries and are used with the intention to prevent and treat venous and arterial thromboembolism. Because of side effects and the necessity of dose adjustment of unfractionated heparins and coumarins, low-molecular-weight heparins, heparinoids, and direct systemically applied thrombin inhibitors were developed. Because of limitations of these anticoagulants, synthetic indirect and direct factor Xa inhibitors and direct thrombin inhibitors were further developed with the aim to improve the benefit/risk ratio for anticoagulant therapy of patients using a simplified mode of action. This overview describes the results of some recent studies of these inhibitors of blood coagulation.