Low-Dose Aspirin Dosing Recommendation
The current recommended dose of low-dose aspirin is 75-162 mg daily, with 75-81 mg being the optimal dose that balances cardiovascular protection with bleeding risk reduction. 1, 2
Optimal Dosing Range
75-81 mg daily is the preferred dose for both primary and secondary prevention, as this represents the lowest effective dose that maintains cardiovascular benefits while minimizing gastrointestinal bleeding and other adverse effects 1, 2
The most common low-dose formulation in the United States is 81 mg 1
Clinical trials have used doses ranging from 50-650 mg daily, but evidence demonstrates that lower doses (75-162 mg) achieve similar risk reductions to higher doses without the increased side effects 1
Evidence Supporting Lower Doses
There is no evidence that higher doses provide superior cardiovascular protection compared to 75-162 mg daily 1
The ADAPTABLE trial confirmed no difference in cardiovascular events or bleeding between 81 mg and 325 mg daily doses, supporting use of the lower dose 2
Gastrointestinal bleeding risk is dose-dependent, with lower doses causing significantly fewer adverse effects while maintaining efficacy 3, 4
Context-Specific Dosing
Secondary Prevention (Established CVD)
- 75-162 mg daily for patients with history of myocardial infarction, stroke, or atherosclerotic cardiovascular disease 1, 2
- European guidelines specifically recommend 75-100 mg daily for lifelong therapy after initial dual antiplatelet therapy 2
Primary Prevention (No Prior CVD)
- 75-162 mg daily may be considered for high-risk patients: adults with diabetes aged ≥50 years who have at least one additional major cardiovascular risk factor (hypertension, dyslipidemia, smoking, family history, or albuminuria) and are not at increased bleeding risk 1, 2
- Not recommended for low-risk individuals (age <50 years with no additional risk factors) as bleeding risks outweigh minimal benefits 1
Acute Coronary Syndromes
- Loading dose of 162-325 mg should be given immediately upon presentation, followed by maintenance dose of 75-100 mg daily 5
Critical Caveats
Bleeding risk increases with age: Major gastrointestinal bleeding occurs at approximately 5 per 1,000 per year in real-world settings, with higher rates (4-12 per 1,000 over 5 years) in elderly patients 1, 2, 5
Contraindications include: active bleeding, bleeding disorders, concurrent anticoagulation, recent gastrointestinal bleeding, uncontrolled hypertension, and age <21 years (Reye syndrome risk) 1, 5
For aspirin allergy: clopidogrel 75 mg daily should be substituted 1, 2
Using the lowest effective dose (75-81 mg) is particularly important in elderly patients to minimize bleeding while maintaining efficacy 2, 5