From the Research
For hospitalized patients already on clopidogrel and aspirin who need DVT prophylaxis, add low-dose subcutaneous heparin or low molecular weight heparin (LMWH). Recommended regimens:
- Unfractionated heparin: 5,000 units subcutaneously every 8-12 hours
- Enoxaparin (LMWH): 40 mg subcutaneously once daily Continue the patient's current clopidogrel and aspirin regimen. Monitor for increased bleeding risk, particularly gastrointestinal bleeding. Assess renal function and adjust LMWH dose if needed for patients with impaired kidney function. This approach provides necessary DVT prophylaxis while maintaining the patient's antiplatelet therapy. Heparin or LMWH work through a different mechanism (inhibiting clotting factors) than clopidogrel and aspirin (antiplatelet effects), allowing for complementary thromboprophylaxis. The low doses used for prophylaxis generally have an acceptable bleeding risk when combined with dual antiplatelet therapy, but close monitoring is essential, as supported by the most recent study 1.
Key considerations:
- The most recent and highest quality study 1 suggests that therapeutic-dose LMWH reduces major thromboembolism and death compared with institutional standard heparin thromboprophylaxis among inpatients with COVID-19 with very elevated D-dimer levels.
- Another study 2 found no increased risk of venous thromboembolism in high-risk patients continuing their dose of 75 mg aspirin compared to healthier patients given low-molecular-weight heparin.
- However, the study 1 provides more relevant and recent evidence for DVT prophylaxis in hospitalized patients, and its findings should be prioritized.
- It is essential to weigh the benefits of DVT prophylaxis against the risk of bleeding, particularly in patients with impaired renal function or those at high risk of gastrointestinal bleeding.
- Close monitoring and regular assessment of renal function are crucial to adjust LMWH dose and minimize the risk of bleeding complications.