Evolutionary Trend of Thrombolytics

Thrombolytic drugs have been used in the clinical arena to treat a wide variety of venous and arterial thromboembolic disorders which are a main cause of death. Thrombolytic molecules are plasminogen activators that convert the inactive plasminogen to the active proteolytic enzyme plasmin which dissolves the blood clot. Fibrin specific plasminoactivators such as tissue – type plasmino activator (t-PA), single chain urokinase type PA, staphylokinase etc. are superior to the non-specific ones such as streptokinase and two chain urokinase-type-PA (tcu-PA). The main advantage of the latest generation of International Journal of Bio-Science and Bio-Technology Vol. 2, No. 4, December, 2010 52 fibrinolytic drugs for treating acute myocardial infarction (MI) is their ease of administration. Four thrombolytic drugs are currently available in market: alteplase, reteplase, streptokinase and tenecteplase. Streptokinase became the most widely used drug due to its low cost. However, newer agents have a longer half-life, making them easier to deliver, but these also are associated with bleeding complications. In a search to overcome these drawbacks, many efforts have been made to develop the more potent thrombolytic agents without bleeding complications. In this review, different generations of thrombolytic agents have been discussed