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

• A. 3 hours after onset
• B. Within 4.5 hours of onset in eligible patients
• C. 6 hours after onset
• D. 12 hours after onset

Answer: (B)

The main idea is that intravenous thrombolysis for ischemic stroke has a strict time window to balance benefits with bleeding risk. For eligible patients, the recommended window is within 4.5 hours from when symptoms started. Giving the clot-dissolving medication as soon as possible improves the chances of restoring blood flow and reducing disability, but extending treatment beyond about 4.5 hours markedly increases the risk of hemorrhage with less chance of meaningful benefit.

In practice, before giving IV thrombolysis, clinicians screen for contraindications and obtain imaging to rule out hemorrhage, ensuring the patient is truly within the time window and suitable for therapy. The other time options fall outside the approved window for routine IV thrombolysis (though other treatments like mechanical thrombectomy can be considered in select cases, especially for large vessel occlusions, within a different time frame).