Hirudin can treat blood clots, but its mechanism of action is not to dissolve the clot, but to inhibit its formation. The formation of thrombus is mainly caused by a series of complex changes after hydrolysis of proteins by thrombin, which eventually causes clotting and thrombosis.
Hirudin, however, is an effective anticoagulant ingredient derived from the Chinese herbal medicine leech, which inactivates the activity of thrombin and therefore has a strong anticoagulant effect, thereby inhibiting thrombus formation. It belongs to the clinical use as an adjunct to thrombolytic therapy for acute myocardial infarction, and can also be used for the prevention and treatment of arterial and venous thrombotic diseases, diffuse intravascular coagulation, anticoagulation in haemodialysis, etc. It is usually administered intravenously, and genetically recombinant hirudin is now more commonly used in clinical practice.