In ischemic stroke presenting after 4.5 hours from onset, which therapy is indicated?

• A. Aspirin
• B. Tissue plasminogen activator
• C. Heparin
• D. Clopidogrel

Answer: (B)

The key idea is that thrombolytic therapy for ischemic stroke has a strict time window. Intravenous tissue plasminogen activator is proven beneficial only within about four and a half hours of onset. Once you’re past that window, the risk of serious bleeding, including symptomatic intracerebral hemorrhage, outweighs any potential benefit, so giving tPA is not indicated.

In a patient who presents after 4.5 hours, the recommended acute treatment is antiplatelet therapy, with aspirin being the typical first choice once hemorrhage has been ruled out on brain imaging. This reduces the risk of early recurrent stroke and supports better outcomes. Heparin isn’t used in the acute phase for ischemic stroke because it hasn’t shown benefit and adds bleeding risk. Clopidogrel can be used in certain circumstances (e.g., if aspirin is contraindicated), but aspirin is the standard initial therapy in this time frame.

So, aspirin is the best answer in this scenario.