What is the optimal time of day to take acetylsalicylic acid (aspirin) to reduce the risk of cerebrovascular accident (stroke) and myocardial infarction (heart attack)?

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Last updated: February 11, 2025View editorial policy

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From the Research

Optimal Time of Day to Take Aspirin

The optimal time of day to take acetylsalicylic acid (aspirin) to reduce the risk of cerebrovascular accident (stroke) and myocardial infarction (heart attack) is a topic of ongoing research.

  • Studies have investigated the effect of taking aspirin in the morning versus the evening on platelet aggregation and blood pressure in patients with coronary heart disease and arterial hypertension 1, 2.
  • The results of these studies suggest that taking aspirin in the evening may be associated with a significant reduction in platelet aggregation and blood pressure, which could potentially reduce the risk of stroke and heart attack 1, 2.
  • However, the optimal dose of aspirin and the timing of its administration may vary depending on individual patient characteristics, such as sex and cardiovascular risk factors 1, 3.

Aspirin Dosing and Cardiovascular Risk Reduction

  • The use of aspirin for the secondary prevention of myocardial infarction, ischemic stroke, and vascular death is well established, and current guidelines recommend its use in patients with atherosclerotic cardiovascular disease (ASCVD) 4.
  • The effectiveness of aspirin in reducing cardiovascular risk has been demonstrated in numerous studies, including those that have investigated its use in patients with coronary heart disease, arterial hypertension, and prosthetic heart valves 3, 5.
  • However, the optimal dose of aspirin for cardiovascular risk reduction is still a topic of debate, with some studies suggesting that lower doses (e.g., 75-81 mg/day) may be as effective as higher doses (e.g., 325 mg/day) in reducing the risk of stroke and heart attack 3, 5.

Timing of Aspirin Administration

  • The timing of aspirin administration may also play a role in its effectiveness in reducing cardiovascular risk.
  • Studies have shown that taking aspirin in the evening may be associated with a greater reduction in platelet aggregation and blood pressure compared to taking it in the morning 1, 2.
  • However, more research is needed to confirm these findings and to determine the optimal timing of aspirin administration for cardiovascular risk reduction.

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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