What are the guidelines for transitioning from warfarin to Eliquis (apixaban)?

Guidelines for Transitioning from Warfarin to Eliquis (Apixaban)

When switching from warfarin to apixaban, discontinue warfarin and start apixaban when the INR is below 2.0. 1 This approach ensures adequate anticoagulation coverage while minimizing bleeding risk during the transition.

Rationale for Switching

Apixaban and other direct oral anticoagulants (DOACs) are generally preferred over vitamin K antagonists like warfarin for patients with non-valvular atrial fibrillation due to:

• Lower risk of intracranial hemorrhage 2, 3
• No need for routine INR monitoring 2
• Fewer drug and food interactions 3
• More predictable anticoagulant effect 3
• Similar or superior efficacy in stroke prevention 2

Step-by-Step Transition Protocol

1. Check INR levels:

   • Monitor INR while on warfarin
   • Begin transition when INR falls below 2.0 1

2. Discontinue warfarin:

   • Stop warfarin completely
   • Do not overlap warfarin and apixaban 2, 1

3. Start apixaban:

   • Begin standard dosing of apixaban immediately once INR <2.0 1
   • For non-valvular AF: 5 mg twice daily (standard dose) 1
   • Reduced dose (2.5 mg twice daily) for patients with at least 2 of 3 criteria:
     • Age ≥80 years
     • Body weight ≤60 kg
     • Serum creatinine ≥1.5 mg/dL 3, 1

4. Post-transition monitoring:

   • No routine coagulation monitoring required
   • Regular assessment of renal function, liver function, and complete blood count 3
   • Monitor for signs of bleeding or thrombosis

Special Considerations

Renal Function

• Apixaban has lower renal clearance (25%) compared to other DOACs 3
• For patients with CrCl 15-29 mL/min: consider reduced dose of 2.5 mg twice daily 3
• For patients with end-stage renal disease or on dialysis: apixaban may be reasonable 2, 4

Perioperative Management

For planned procedures requiring interruption of anticoagulation:

• Low bleeding risk procedures: Discontinue apixaban 24 hours before procedure 2
• Moderate/high bleeding risk procedures: Discontinue apixaban 48 hours before procedure 2, 1
• Resume apixaban as soon as adequate hemostasis is achieved 1

Contraindications for Apixaban

• Active pathological bleeding 1
• Severe hypersensitivity to apixaban 1
• Mechanical heart valves (warfarin remains the only recommended option) 3

Common Pitfalls to Avoid

1. Overlapping therapy: Do not administer warfarin and apixaban simultaneously 2, 1

2. Incorrect INR monitoring: INR is not a valid measure of apixaban's anticoagulant effect 1

3. Inappropriate dosing: Failing to adjust dose based on age, weight, and renal function 1

4. Medication interactions: Be cautious with combined P-gp and strong CYP3A4 inhibitors (e.g., ketoconazole, itraconazole, ritonavir) which require dose reduction 1

5. Abrupt discontinuation: Premature discontinuation of apixaban without alternative anticoagulation increases thrombotic risk 1

Follow-up Recommendations

• Assess renal function at least annually, or every 6 months in elderly patients 3
• Regular assessment of bleeding risk factors and medication adherence 3
• Evaluate for any new drug interactions at each visit

By following these guidelines, the transition from warfarin to apixaban can be accomplished safely and effectively while maintaining appropriate anticoagulation coverage throughout the process.