Should I continue Lovenox (Enoxaparin) or switch to Eliquis (Apixaban) for post-operative prophylaxis in a patient with anemia and an INR of 1.1?

Management of Post-Operative Thromboprophylaxis in a Patient with Anemia

You should switch from Lovenox to Eliquis (apixaban) for this patient with a hemoglobin drop from 9.7 to 8.0 g/dL while on post-operative prophylactic Lovenox.

Rationale for Switching to Eliquis

Patient's Current Status

• Hemoglobin has dropped from 9.7 to 8.0 g/dL while on Lovenox 40 mg SC daily
• INR is 1.1 (normal)
• Patient is receiving post-operative VTE prophylaxis

Benefits of Switching to Eliquis

1. Reduced Bleeding Risk with Similar Efficacy

   • Apixaban has been shown to have a better safety profile regarding bleeding compared to enoxaparin (Lovenox) 1
   • A study demonstrated that apixaban resulted in fewer hemorrhagic complications while maintaining efficacy for thromboprophylaxis 1

2. Hemoglobin Considerations

   • The patient's hemoglobin has dropped significantly (1.7 g/dL)
   • Postoperative anemia with Hb <8 g/dL is associated with increased morbidity 2
   • A significant drop in hemoglobin (≥2 g/dL) is a predictor of poor outcomes in postoperative patients 3

3. Dosing Recommendation

   • For post-operative prophylaxis, Eliquis (apixaban) 2.5 mg twice daily is the recommended dose 4
   • Initiate Eliquis 12-24 hours after surgery 4

Implementation Plan

1. Discontinue Lovenox

   • Stop the current Lovenox 40 mg SC daily regimen

2. Start Eliquis

   • Begin apixaban 2.5 mg orally twice daily 4
   • No overlap is needed - start Eliquis at the time the next dose of Lovenox would have been due 4

3. Monitoring Parameters

   • Follow hemoglobin levels to ensure stabilization
   • Monitor for signs of bleeding (petechiae, ecchymosis, hematuria, melena)
   • Watch for signs of thrombosis (limb swelling, pain, warmth)

Important Considerations

Duration of Prophylaxis

• Extended prophylaxis (up to 35 days) is recommended for high-risk orthopedic procedures 4
• For other surgeries, duration should be based on patient mobility and risk factors

Advantages of Apixaban Over Enoxaparin

• Oral administration (improved adherence) vs. subcutaneous injections
• No need for anti-Xa monitoring
• Fixed dosing regimen
• Similar or better efficacy with potentially lower bleeding risk 5, 1

Cautions

• If the patient has severe renal impairment, dose adjustment may be needed
• If the patient weighs ≤60 kg AND is ≥80 years AND has serum creatinine ≥1.5 mg/dL, a lower dose would be indicated 4
• Avoid in patients with active pathological bleeding 4

Evidence Summary

The ADVANCE trials demonstrated that apixaban was associated with lower rates of venous thromboembolism compared to enoxaparin without increased bleeding 6. Additionally, a single-center study showed that apixaban resulted in a lower VTE incidence (4.5% vs. 8.9%) and fewer hemorrhagic complications compared to enoxaparin 1.

The patient's hemoglobin drop is concerning, as postoperative anemia with Hb <8 g/dL is associated with increased morbidity, particularly in patients with cardiovascular disease 2. Switching to apixaban provides effective thromboprophylaxis while potentially reducing the risk of further bleeding.