Thrombolytic agents--an overview.

Abstract

Thrombolysis today has become a routine option not only in the treatment of acute myocardial infarction but also in many other manifestations of thromboembolic disease. Until one decade ago, only two plasminogen activators, streptokinase and urokinase, were available for clinical use. They were characterized by limited thrombolytic potencies and major side effects including systemic fibrinogen breakdown, bleeds and stroke. This has prompted the search for new plasminogen activators with better pharmacological and clinical profiles. The first such new plasminogen activators were Anistreplase, a chemically modified version of the streptokinase-plasminogen-activator-complex and tissue-type plasminogen-activator produced by recombinant technology. Both new substances have fueled the development in modern thrombolytic treatment. While the clinical progress with t-PA was confirmed in large, double-blind, randomized, multicenter trials, no real superiority of anistreplase over the traditional plasminogen activators urokinase and streptokinase has been substantiated. While the clinical use of t-PA today has been established for acute myocardial infarction, pulmonary embolism and deep vein thrombosis, current research is focused on further plasminogen activators with further improved thrombolytic properties. This review summarizes the current knowledge on the biochemical and pharmacological properties of the first, second and future generation of plasminogen activators.