Aspirin Therapy for Ischemic Stroke

Initial Aspirin Therapy

The American Heart Association recommends that all acute ischemic stroke patients not already on an antiplatelet agent and not receiving tPA therapy should receive at least 160 mg of aspirin immediately as a one-time loading dose after brain imaging has excluded intracranial hemorrhage and dysphagia screening has been performed and passed 1
For patients treated with tPA, aspirin should be delayed until after the 24-hour post-thrombolysis scan has excluded intracranial hemorrhage 1
Aspirin (81 to 325 mg daily) should then be continued indefinitely or until an alternative antithrombotic regimen is started 1

For non-cardioembolic ischemic stroke or TIA, aspirin 50–325 mg is recommended for long-term secondary prevention 2
The optimal dose range appears to be 75-162 mg daily for long-term maintenance therapy, which balances efficacy with reduced bleeding risk 3, 4
For patients with extracranial carotid or vertebral atherosclerosis who have had ischemic stroke or TIA, treatment with aspirin alone (75–325 mg daily) should be continued 3

For patients with stroke related to 50%–99% intracranial stenosis, a higher dose of 325 mg/day aspirin is specifically recommended 2
For patients with recent minor (NIHSS ≤3) non-cardioembolic ischemic stroke or high-risk TIA (ABCD2 score ≥4), dual antiplatelet therapy (aspirin plus clopidogrel) should be used for 21-90 days, followed by single antiplatelet therapy 2

In patients already on aspirin prior to ischemic stroke or TIA, clopidogrel 75 mg daily may be considered as an alternative 1
For patients who cannot tolerate aspirin, clopidogrel 75 mg daily is recommended as an alternative 3

Aspirin should not be considered a substitute for other acute interventions for treatment of stroke, including intravenous tPA 6
For patients with cardioembolic stroke (e.g., atrial fibrillation), oral anticoagulation is preferred over antiplatelet therapy 2
When switching from dual antiplatelet therapy to monotherapy, ensure patients understand the importance of continuing at least one antiplatelet agent indefinitely 2
For patients requiring warfarin in addition to aspirin (e.g., for atrial fibrillation), the combination increases bleeding risk and should be monitored closely 7
In patients with dysphagia, aspirin may be given by enteral tube (80 mg daily) or by rectal suppository (325 mg daily) 1