Trombolytic

Thrombolytics, also called thrombolytic agents or plasminogen activators, are medicines that dissolve clots by promoting the conversion of plasminogen to plasmin, the enzyme that degrades fibrin. They can be broadly classified as non-fibrin–specific agents (such as streptokinase and urokinase) and fibrin-specific recombinant tissue plasminogen activators (rtPA) such as alteplase, tenecteplase, and reteplase. Streptokinase forms a complex with plasminogen to generate plasmin, while rtPA acts preferentially at the clot site, leading to more targeted fibrinolysis.

Indications include acute coronary occlusion in ST-elevation myocardial infarction when percutaneous intervention is not immediately available, acute ischemic stroke within approved time limits, and selected cases of massive pulmonary embolism or deep vein thrombosis. Dosing and agent choice depend on the condition and local protocols.

Administration is usually via intravenous infusion or bolus, with careful monitoring for bleeding, blood pressure changes, and neurological status. Time windows are critical: treatment for STEMI is most beneficial within hours of onset, ischemic stroke within a narrow window, and pulmonary embolism decisions depend on clinical severity.

Risks include major bleeding and intracranial hemorrhage, as well as allergic reactions and hypotension. Contraindications include active internal bleeding, recent intracranial surgery or hemorrhagic stroke, known vascular malformations, severe uncontrolled hypertension, and certain pregnancy considerations. The use of thrombolytics requires assessment by experienced clinicians and is typically performed in settings equipped to manage bleeding and perform rapid imaging and monitoring.