From the Guidelines
Aspirin should be taken for an indefinite period after a stroke, as long as there are no contraindications, to prevent recurrent stroke.
Recommended Duration of Aspirin Therapy
The recommended duration of aspirin therapy after a stroke is not explicitly stated in terms of a specific time frame, but rather as a long-term management strategy to prevent recurrent stroke.
- The administration of aspirin within 24-48 hours after stroke onset is recommended for the treatment of most patients 1, 2.
- The primary effects of aspirin are attributable to a reduction in early recurrent stroke, with a small but statistically significant decline in mortality and unfavorable outcomes 3, 4.
- Aspirin can be administered within the first 48 hours because of reasonable safety and a small benefit, and its use is recommended as part of long-term management after acute stroke 5.
Important Considerations
- The dose of aspirin is typically 325 mg orally, and it should be started within 24-48 hours after stroke onset, unless there are contraindications such as aspirin allergy 2.
- For patients treated with intravenous thrombolysis, aspirin administration is generally delayed until more than 24 hours after treatment 1.
- The relative indications for the long-term administration of antiplatelet agents to prevent recurrent stroke are beyond the scope of the provided guidelines, but aspirin is a commonly recommended agent for this purpose 4.
The FDA Drug Labels for aspirin (PO) do not address this question.
From the Research
Aspirin Dosage and Duration for Stroke Prevention
The recommended duration for taking aspirin after a stroke is not explicitly stated in the provided studies. However, the following information can be gathered:
- Aspirin is recommended for secondary prevention in all patients with established cardiovascular disease, including those who have had a stroke 6.
- Life-long therapy with low doses (75-150 mg daily) of aspirin is recommended for secondary prevention 6.
- The effects of aspirin on early recurrent stroke are most evident in the first few weeks after a stroke, with a significant reduction in risk of recurrent ischemic stroke and disabling or fatal ischemic stroke 7.
- The benefit of aspirin in reducing the risk of recurrent stroke diminishes over time, with no significant benefit after 12 weeks 7.
Aspirin Dosage for Stroke Prevention
The optimal dosage of aspirin for stroke prevention is not clearly established, but the following information is available:
- A dose of 160 mg/day is effective in preventing recurrent stroke or death in patients with a history of stroke or transient ischemic attack (TIA) 8.
- A higher loading dose of aspirin (160-325 mg) can be beneficial in treating acute ischemic stroke, although there is an increased risk of minor bleeding 9.
- The risk of major bleeding with 160 mg/day is similar to that with 80 mg/day, and the risk of fatal bleeding is the same with 80 and 160 mg/day 8.
Key Points
- Aspirin is recommended for secondary prevention in patients with established cardiovascular disease, including those who have had a stroke.
- The optimal duration and dosage of aspirin for stroke prevention are not clearly established, but life-long therapy with low doses (75-150 mg daily) is recommended.
- Higher loading doses of aspirin (160-325 mg) may be beneficial in treating acute ischemic stroke, but may increase the risk of minor bleeding.