From the Guidelines
Antiplatelet therapy is a cornerstone of stroke management, both for acute treatment and long-term prevention, with aspirin being the most extensively tested antiplatelet agent. For acute ischemic stroke, aspirin (325mg initially, then 81-325mg daily) should be started within 24-48 hours of symptom onset, unless the patient receives thrombolytic therapy (in which case, delay aspirin for 24 hours) 1. The primary effect of aspirin is likely attributable to prevention of recurrent events, rather than limiting the neurological consequences of the acute stroke itself.
Key Considerations for Antiplatelet Therapy in Stroke Management
- For long-term secondary prevention after non-cardioembolic stroke, options include aspirin (81mg daily), clopidogrel (75mg daily), or the combination of aspirin plus extended-release dipyridamole (25/200mg twice daily) 1.
- Dual antiplatelet therapy with aspirin plus clopidogrel is generally recommended only for specific situations like recent minor stroke or high-risk TIA (for 21-90 days), or for intracranial stenosis (for 90 days), as longer-term dual therapy increases bleeding risk without additional benefit for most patients 1.
- In patients with atrial fibrillation and stroke, anticoagulation rather than antiplatelet therapy is preferred.
- Antiplatelet medications work by preventing platelet aggregation through different mechanisms: aspirin inhibits cyclooxygenase, clopidogrel blocks ADP receptors, and dipyridamole increases cyclic AMP.
- Treatment should be individualized based on stroke etiology, comorbidities, bleeding risk, and medication interactions 1.
Recent Guidelines and Recommendations
- The 2018 Canadian Stroke Best Practice Recommendations suggest that if a patient experiences a stroke while on ASA, it may be reasonable to consider switching to clopidogrel; if a patient experiences a stroke while on clopidogrel, it may be reasonable to consider switching to combined acetylsalicylic acid (25 mg) and extended-release dipyridamole (200 mg) 1.
- The use of antiplatelet agents has been shown to reduce the risk of recurrent stroke, with aspirin associated with a 19% reduction in the risk of future ischemic stroke and a 23% reduction in stroke of unknown cause, without a significantly increased risk of hemorrhagic stroke 1.
From the FDA Drug Label
The FDA drug label does not answer the question.
From the Research
Role of Antiplatelet Agents in Stroke Management
The management of stroke, also known as cerebrovascular accident, involves the use of antiplatelet agents to prevent recurrent ischemic events.
- Antiplatelet monotherapy is beneficial in acute ischemic stroke and secondary stroke prevention, as established by several large randomized trials 2.
- Long-term therapy with aspirin, clopidogrel, or aspirin plus extended-release dipyridamole is recommended for secondary stroke prevention in patients with noncardioembolic ischemic stroke 2, 3.
- Short-term dual antiplatelet therapy with aspirin and clopidogrel is superior to antiplatelet monotherapy in secondary stroke prevention for patients with mild noncardioembolic stroke or high-risk transient ischemic attack 2, 4.
Dual Antiplatelet Therapy
Dual antiplatelet therapy is associated with an increased risk of major bleeding, particularly when treatment is extended for more than 30 days 2, 4.
- Aspirin plus ticagrelor is superior to aspirin monotherapy for preventing recurrent ischemic stroke, but this combination is associated with a higher risk of hemorrhagic complications 2, 5.
- In patients with symptomatic intracranial stenosis, aggressive medical management in addition to dual antiplatelet therapy up to 90 days is recommended 2.
Individualized Treatment
The specific antiplatelet regimen should be individualized based on stroke characteristics, time from symptom onset, and patient-specific predisposition to develop hemorrhagic complications 2, 6.
- Clinicians should carefully assess the pros and cons in each case and individualize the need for prolonged dual antiplatelet therapy 6.
- Treatment with an antiplatelet agent is recommended to reduce recurrent stroke and death in patients with non-cardioembolic ischemic stroke or transient ischemic attack 6, 5.