dose of aspirin

Last edited 05/2021 and last reviewed 06/2021

  • the minimum effective dose for aspirin, taken from evidence from secondary prevention studies, is in the order of 75 mg per day for patients at risk of arteriothrombotic events and 160 mg/day for the treatment of acute myocardial infarction (1)
  • a systematic review concluded that "..currently available clinical data do not support the routine, long-term use of aspirin dosages greater than 75 to 81 mg/d in the setting of cardiovascular disease prevention. Higher dosages, which may be commonly prescribed, do not better prevent events but are associated with increased risks of gastrointestinal bleeding..." (2)
  • dose of aspirin in the prevention of cardiovascular disease:
    • an open-label pragmatic trial found no differences in cardiovascular events (event rate 7.28% vs 7.51%; HR 1.02; 95% CI 0.91 to 1.14) or major bleeding (0.63% vs 0.60%; HR 1.18; 95% CI, 0.79 to 1.77) in patients with CVD assigned to 81 mg or 325 mg of aspirin daily, respectively (3)
      • there was substantial dose switching to 81 mg of daily aspirin and no significant differences in cardiovascular events or major bleeding between patients assigned to 81 mg and those assigned to 325 mg of aspirin daily