Abstract
Biochemical, pharmacological and first clinical findings on synthetic, low molecular weight inhibitors of serine proteinases of the blood considered to be therapeutically relevant thrombin inhibitors are reviewed. Their effect is due to an inhibition of the thrombin-fibrinogen reaction as well as of other effects of thrombin in the coagulation system. Synthetic thrombin inhibitors represent approaches to the development of new types of anticoagulants.