What is the recommended dosage of Ecospirin (aspirin) for Deep Vein Thrombosis (DVT) prophylaxis, given the twice daily (bd) regimen?

Aspirin for DVT Prophylaxis: Dosage Recommendations

For DVT prophylaxis, low-dose aspirin (75-100 mg daily) is recommended rather than twice-daily (bd) dosing, as higher doses have not demonstrated increased efficacy but may increase bleeding risk. 1

Aspirin's Role in DVT Prophylaxis

Aspirin is not considered a first-line agent for DVT prophylaxis in most clinical scenarios. The American College of Chest Physicians recommends a dose range of 75-100 mg daily when aspirin is used for DVT prophylaxis 1. This is important to note because:

• Low-molecular-weight heparins (LMWHs), unfractionated heparin (UFH), direct oral anticoagulants (DOACs), and fondaparinux are generally more effective and are considered first-line agents for DVT prophylaxis 2
• Aspirin has been shown to be less effective at preventing recurrent VTE than anticoagulants 2

Recommended Dosing

When aspirin is used for DVT prophylaxis, the dosing recommendations are:

• American College of Chest Physicians: 75-100 mg daily 1
• National Comprehensive Cancer Network (NCCN): 81-325 mg daily 1

There is no evidence supporting twice-daily (bd) dosing of aspirin for DVT prophylaxis. The standard practice is once-daily administration.

Specific Clinical Scenarios

Orthopedic Surgery

• Low-dose aspirin (75-100 mg daily) may be considered for selected orthopedic surgery patients without additional risk factors 1
• A study examining aspirin after total knee arthroplasty found that low-dose aspirin (81 mg twice daily) was not inferior to high-dose aspirin (325 mg twice daily) for VTE prevention 3

After Completion of Standard Anticoagulation

• In patients with an unprovoked proximal DVT or PE who are stopping anticoagulant therapy, aspirin may be suggested over no aspirin to prevent recurrent VTE 2
• However, aspirin is much less effective at preventing recurrent VTE than anticoagulants and should not be considered a reasonable alternative to anticoagulant therapy in patients who want extended therapy 2

Common Pitfalls to Avoid

1. Mistaking aspirin as equivalent to anticoagulants: Aspirin is not a suitable alternative to anticoagulation in most DVT prophylaxis scenarios 1

2. Using unnecessarily high doses: Doses higher than 100 mg daily do not provide additional protection against VTE but may increase bleeding risk 1

3. Inappropriate twice-daily dosing: Standard recommendations for aspirin in DVT prophylaxis call for once-daily dosing, not twice-daily administration 1

4. Failing to reassess aspirin use: When patients stop anticoagulant therapy, aspirin use should be reevaluated, as it may have been discontinued when anticoagulants were started 2

Conclusion

For DVT prophylaxis, if aspirin is chosen as the agent, a once-daily low-dose regimen (75-100 mg) is recommended rather than twice-daily dosing. However, it's important to recognize that aspirin is generally less effective than anticoagulants for DVT prophylaxis and should be reserved for specific clinical scenarios or when anticoagulants are contraindicated.