Aspirin Loading in Acute Ischemic Stroke
Yes, aspirin should be administered as a loading dose of 160-325 mg within 24-48 hours after onset of acute ischemic stroke, after intracranial hemorrhage has been ruled out by neuroimaging. 1
Evidence-Based Recommendations
The American Heart Association/American Stroke Association (AHA/ASA) guidelines consistently recommend early aspirin administration in acute ischemic stroke:
- Administration of aspirin is recommended within 24-48 hours after stroke onset 1
- A single loading dose of 160-325 mg should be given after excluding intracranial hemorrhage 1
- For patients treated with IV alteplase (tPA), aspirin administration should generally be delayed until 24 hours later 1
Clinical Benefits
Early aspirin administration provides several important benefits:
- Reduces stroke mortality and decreases morbidity 1, 2
- Prevents approximately 9 deaths or non-fatal strokes per 1000 patients treated in the first few weeks 2
- Primarily works by reducing early recurrent stroke rather than limiting neurological consequences of the initial stroke 1
- Improves long-term functional outcomes, with about 13 fewer patients dead or dependent per 1000 at follow-up 2
Administration Protocol
- Timing: Administer within 24-48 hours after stroke onset
- Dosing: 160-325 mg initial loading dose
- Prerequisites:
- CT scan or MRI must first rule out intracranial hemorrhage
- Do not administer within 24 hours of thrombolytic therapy
Special Considerations
- Alternative routes: For patients with impaired swallowing, rectal aspirin (325 mg) or aspirin via enteral tube (81 mg) are reasonable alternatives 1
- Minor stroke patients: In patients with minor stroke (NIHSS ≤3) or high-risk TIA, consider dual antiplatelet therapy (aspirin plus clopidogrel) initiated within 24 hours 1
- Contraindications: Avoid in patients with aspirin allergy, active gastrointestinal bleeding, or when thrombolytic therapy is planned 1
Important Caveats
- Aspirin should not be considered a substitute for other acute interventions like IV alteplase or mechanical thrombectomy 1
- The administration of aspirin as adjunctive therapy within 24 hours of thrombolytic therapy is not recommended 1
- Clopidogrel alone is not recommended for the treatment of acute ischemic stroke 1
- The primary benefit appears to be prevention of early recurrent stroke rather than treatment of the initial stroke itself 1
Early aspirin administration represents a simple, cost-effective intervention that significantly improves outcomes in acute ischemic stroke patients when administered appropriately after excluding hemorrhagic stroke.