From the Guidelines
For DVT prophylaxis, aspirin (ASA) is typically prescribed at a dose of 100 mg daily, as supported by the WARFASA and ASPIRE trials 1. The most common regimen is 100 mg (low-dose) once daily. Aspirin works by inhibiting platelet aggregation through irreversible inhibition of cyclooxygenase, reducing thromboxane A2 production and preventing clot formation.
- The available evidence supports daily doses of aspirin in the range of 75–100 mg for the long term prevention of serious vascular events in high-risk patients 1.
- While aspirin is considered less effective than anticoagulants like low molecular weight heparin or direct oral anticoagulants for high-risk patients, it offers a reasonable balance of efficacy and safety for moderate-risk patients, particularly following orthopedic procedures.
- Patients should take aspirin with food to minimize gastrointestinal irritation, and those with aspirin allergy, active bleeding, or high bleeding risk should discuss alternative options with their healthcare provider.
- The use of aspirin for DVT prophylaxis should be individualized, taking into account the patient's risk factors and medical history 1.
From the Research
DVT Prophylaxis with Aspirin
- The optimal dose of aspirin for DVT prophylaxis is not clearly established, but studies suggest that low-dose aspirin (81 mg twice daily) may be as effective as regular-dose aspirin (325 mg twice daily) in preventing symptomatic VTE after total hip arthroplasty (THA) 2.
- A study of 7488 patients who underwent THA found no significant difference in the incidence of symptomatic VTE, bleeding, or mortality between low-dose and standard-dose aspirin groups 2.
- The use of aspirin for VTE prophylaxis is recommended by some guidelines, but the dose and duration of treatment may vary depending on individual patient risk factors and surgical procedures 3, 2.
Comparison with Other Anticoagulants
- Low-molecular-weight heparin (LMWH) and fondaparinux are also effective in reducing the risk of DVT, but may have a higher risk of bleeding compared to aspirin 4, 5.
- The choice of anticoagulant for DVT prophylaxis depends on individual patient factors, such as renal function, bleeding risk, and surgical procedure 4, 3.
- Clinical practice guidelines recommend the use of LMWH, fondaparinux, or adjusted-dose warfarin for VTE prophylaxis in certain patient populations, but the evidence for specific agent selection is limited 6.