How do I transition a patient from Lovenox (Enoxaparin) to Coumadin (Warfarin)?

Transitioning from Lovenox (Enoxaparin) to Coumadin (Warfarin)

When transitioning from Lovenox to Coumadin, initiate warfarin concurrently with Lovenox and continue both therapies for at least 5 days and until the INR is ≥2 for 24 hours. 1

Transition Protocol

1. Initial Overlap Period:

   • Start warfarin at 2.5-5 mg daily while continuing Lovenox (enoxaparin) at the full therapeutic dose (1 mg/kg SC every 12 hours) 1
   • Continue both medications simultaneously for a minimum of 5 days 1, 2

2. INR Monitoring:

   • Check INR daily after starting warfarin until stable in the therapeutic range 2
   • Target INR is typically 2-3 for most indications 1

3. Discontinuation of Lovenox:

   • Continue Lovenox until the INR has been ≥2.0 for at least 24 consecutive hours 1
   • Do not discontinue Lovenox prematurely, even if INR rises quickly 2

4. Post-Transition Monitoring:

   • After Lovenox discontinuation, continue frequent INR monitoring (every 2-3 days initially)
   • Once stable, INR monitoring can be extended to intervals of 1-4 weeks 2

Special Considerations

Dosing Adjustments

• For elderly patients or those with liver disease, consider starting with a lower warfarin dose (2.5 mg daily) 2
• Patients with cancer may require more careful monitoring due to increased risk of both thrombosis and bleeding 3

Common Pitfalls to Avoid

1. Premature Discontinuation of Lovenox:

   • Discontinuing Lovenox too early (before achieving stable therapeutic INR) can lead to thrombotic complications
   • Warfarin has a delayed onset of action (takes 5-7 days to reach full effect) 2

2. Inadequate Overlap Period:

   • Insufficient overlap between Lovenox and warfarin is a common error
   • The minimum 5-day overlap is essential regardless of how quickly the INR rises 1, 2

3. Inaccurate INR Timing with Heparin Products:

   • When drawing blood for INR testing, timing matters:
     • Draw blood at least 4 hours after stopping continuous IV heparin
     • Draw blood at least 24 hours after the last subcutaneous heparin/LMWH injection 2

4. Loading Dose Errors:

   • High loading doses (10 mg) don't necessarily lead to faster therapeutic anticoagulation and may increase bleeding risk 4, 5
   • Starting with 5 mg daily is generally safer than 10 mg loading doses 4

Special Populations

Cancer Patients

• For patients with cancer-associated thrombosis, consider whether long-term LMWH might be preferable to warfarin 1
• Cancer patients have higher rates of recurrent thrombosis on warfarin compared to continued LMWH 1

Pregnancy

• Warfarin is contraindicated during pregnancy, especially in the first trimester 1, 3
• If the patient is pregnant or could become pregnant, continue LMWH rather than transitioning to warfarin 1

Mechanical Heart Valves

• Patients with mechanical heart valves require particularly careful monitoring during transition
• Consider more frequent INR testing (daily until stable) 2

By following this protocol, you can safely transition patients from Lovenox to Coumadin while minimizing the risk of thrombotic or bleeding complications.