Daily low doses of aspirin are most commonly prescribed to patients with a high risk of thrombi production to produce an antiplatelet effect. When aspirin is given in low doses (75-150 mg/day), the maximal antiplatelet effect may take several days. At a dose of 160-325 mg/day, the maximal antiplatelet effect of aspirin is faster and can occur in approximately 30 minutes. Therefore, aspirin at low doses may be prescribed for the long-term prevention of heart attacks and strokes, and moderate doses are given in situations where an immediate anti-clotting effect is needed.
A recommendation summary from the United States Preventive Services Task Force (USPSTF) for the use of aspirin in preventing cardiovascular disease can be found in Table 1.
Table 1. Use of Aspirin for the Prevention of Cardiovascular Disease
Population | Recommendation |
Adults aged 40 to 59 years with a 10% or greater 10-year cardiovascular disease (CVD) risk | The decision to initiate low-dose aspirin use for the primary prevention of CVD in adults aged 40 to 59 years who have a 10% or greater 10-year CVD risk should be an individual one. Evidence indicates that the net benefit of aspirin use in this group is small. Persons who are not at increased risk for bleeding and are willing to take low-dose aspirin daily are more likely to benefit. |
Adults 60 years or older | The USPSTF recommends against initiating low-dose aspirin use for the primary prevention of CVD in adults 60 years or older. |