What is the time window for IV thrombolytic therapy in eligible ischemic stroke patients?

• A. Within 24 hours
• B. Within 12 hours
• C. Within 6-8 hours
• D. Within 3-4.5 hours

Answer: (D)

The key idea is that IV thrombolytic therapy for ischemic stroke is time-sensitive: treating as soon as possible improves outcomes, but the risk of bleeding rises with delay. The accepted window for giving IV alteplase (tPA) to eligible adults is up to 4.5 hours after stroke onset. This extended window comes from trials like ECASS III, which showed benefit within 3 to 4.5 hours in selected patients, while earlier data demonstrated clear benefit within 3 hours. In practice, clinicians aim to treat as early as possible and complete rapid assessment to determine eligibility, with a target door-to-needle time of about 60 minutes. So the option reflecting treatment within the 3–4.5 hour span corresponds to the extended, guideline-backed window for IV thrombolysis in eligible patients.