alteplase

Alteplase, also known as recombinant tissue plasminogen activator (rtPA), is a thrombolytic agent used to dissolve clots in several acute medical emergencies. It works by binding to fibrin in a formed clot and converting plasminogen to plasmin, an enzyme that degrades fibrin and promotes clot breakdown. Because alteplase has a short circulating half-life, it is given as a controlled intravenous infusion after careful patient selection and monitoring.

Indications and time window guidance vary by condition. In acute ischemic stroke, alteplase is used within a defined time window from symptom onset, typically within 4.5 hours in eligible adults, withEligibility determined by clinical and imaging criteria. It is also used for acute massive pulmonary embolism with hemodynamic instability and, in select cases, for ST-segment elevation myocardial infarction when percutaneous coronary intervention is not available or feasible.

Administration and dosing. Alteplase is administered by intravenous infusion. Ischemic stroke dosing is 0.9 mg/kg (maximum 90 mg), with 10% given as an IV bolus and the remainder infused over 60 minutes. For STEMI, the regimen is 15 mg IV bolus, followed by 0.75 mg/kg (maximum 50 mg) over 30 minutes, then 0.5 mg/kg (maximum 35 mg) over 60 minutes. For pulmonary embolism, a common regimen is 100 mg IV over 2 hours; some protocols use alternative weight-based regimens.

Safety and contraindications. Major bleeding is the principal safety concern. Absolute contraindications include active internal bleeding, a history of intracranial hemorrhage, known structural cerebral vascular abnormality, recent intracranial surgery or ischemic stroke, malignant intracranial neoplasm, uncontrolled hypertension, and recent major surgery or trauma. Concomitant anticoagulant or antiplatelet therapy increases bleeding risk. Patients require close monitoring for bleeding and neurologic changes during and after treatment.

Names and history. Brand names include Activase (United States) and Actilyse (Europe). Alteplase is a long-standing recombinant form of human tissue plasminogen activator developed for thrombolytic therapy.