Pharmacologic and clinical characteristics of thrombolytic agents.

Arterial and venous thromboembolic events, including myocardial infarction, ischemic stroke, peripheral arterial thrombosis, deep venous thrombosis, and pulmonary embolism are common potentially life-, organ-, and limb-threatening vascular diseases. Anticoagulant therapy is recommended in these settings to prevent further thrombosis pending gradual clearance of the thrombotic occlusion by the endogenous fibrinolytic system. Recognition of the importance of the fibrinolytic system in thrombus resolution has resulted in the development of pharmacologic fibrinolytic (thrombolytic) agents to facilitate rapid restoration of vascular patency. Several plasminogen activator (PA) thrombolytic agents with different pharmacokinetic and pharmacodynamic properties have been developed to treat thrombotic disease. Newer PAs have been developed as "fibrin-specific", bolus-administration drugs to primarily treat acute coronary syndromes. Continuous infusions of these fibrin-specific PAs have become popular for the lysis relatively larger peripheral vascular thromboses. Loss infusion of newer tissue-type plasminogen activator-based PAs may result in an increased risk of bleeding, including intracranial hemorrhage. Currently available data fail to provide compelling evidence that newer PAs offer significantly greater efficacy and safety than well-established agents like urokinase when used to treat peripheral vascular thrombosis.