From the FDA Drug Label
The provided drug labels do not directly mention the indications for thrombolysis (thrombolytic therapy). The FDA drug label does not answer the question.
From the Research
Thrombolysis is indicated for acute ischemic stroke within 4.5 hours of symptom onset, acute ST-elevation myocardial infarction (STEMI) within 12 hours of symptom onset, and massive pulmonary embolism with hemodynamic instability. For ischemic stroke, alteplase (tPA) is administered at 0.9 mg/kg (maximum 90 mg) with 10% given as a bolus and the remainder infused over 60 minutes 1. The most recent and highest quality study, a 2014 Cochrane review, found that thrombolytic therapy, mostly administered up to six hours after ischemic stroke, significantly reduced the proportion of participants who were dead or dependent at three to six months after stroke (odds ratio 0.85,95% confidence interval 0.78 to 0.93) 1.
Key Considerations
- The time window for thrombolysis in acute ischemic stroke has been extended up to 4.5 hours, with the most benefit seen when treatment is initiated within three hours of symptom onset 2, 1.
- Thrombolytic therapy increases the risk of symptomatic intracranial hemorrhage, but this risk is outweighed by the benefits of reduced death and dependency in selected patients 1.
- Absolute contraindications for thrombolysis include active bleeding, recent surgery or trauma, history of intracranial hemorrhage, ischemic stroke within 3 months, known intracranial neoplasm, arteriovenous malformation or aneurysm, and severe uncontrolled hypertension.
Administration and Dosage
- For STEMI, options include alteplase (100 mg over 90 minutes), reteplase (two 10-unit boluses 30 minutes apart), or tenecteplase (single weight-based bolus of 30-50 mg).
- For pulmonary embolism, alteplase 100 mg over 2 hours is standard.
- Rapid administration of thrombolytics is crucial, as efficacy decreases with time, following the principle "time is brain" or "time is muscle," reflecting the urgency to restore blood flow and prevent permanent tissue damage.
Evidence Base
- The evidence for thrombolysis in acute ischemic stroke is based on multiple randomized controlled trials, including the 2014 Cochrane review, which included 27 trials and over 10,000 participants 1.
- The benefits and risks of thrombolysis must be carefully weighed in individual patients, taking into account factors such as age, stroke severity, and medical history.