reteplase

Reteplase is a recombinant thrombolytic agent used to dissolve clots in acute myocardial infarction. It is a truncated form of tissue plasminogen activator (tPA) that lacks several regulatory domains, giving it a longer plasma half-life and allowing administration as two rapid intravenous boluses rather than a longer infusion.

Mechanism: Reteplase activates plasminogen to plasmin, which breaks down fibrin and dissolves thrombi.

Administration and dosing: Given as two IV boluses of 10 units each, administered 30 minutes apart. Anticoagulant and antiplatelet therapies may be used according to protocol; treatment should be accompanied by close monitoring, including serial ECGs and assessment for bleeding.

Indications: Acute myocardial infarction (ST-elevation or non-ST) when primary PCI is not available promptly; not generally first-line where PCI is available.

Contraindications: Active internal bleeding or bleeding diatheses; history of intracranial hemorrhage or ischemic stroke within the past 3 months; intracranial surgery or head trauma within 2 months; known intracranial neoplasm; suspected aortic dissection; severe uncontrolled hypertension; recent major surgery or trauma; pregnancy.

Adverse effects: Bleeding is the principal risk; syncope; hypersensitivity; rarely arrhythmias.

Pharmacokinetics: Rapid onset after bolus; clearance primarily hepatic; half-life short to moderate; effect limited to dissolved fibrin clots.

History and status: Reteplase was approved in 1996 for acute MI; with the expansion of primary PCI and evolving guidelines, its use has declined in many regions; alternatives include alteplase, tenecteplase, and mechanical reperfusion.