What is the recommended protocol for switching from Eliquis (apixaban) to Coumadin (warfarin)?

Switching from Eliquis (Apixaban) to Coumadin (Warfarin)

When transitioning from apixaban to warfarin, you must start warfarin at the usual initial dose (typically 5 mg daily) while simultaneously beginning a parenteral anticoagulant (LMWH or UFH) at the time of the next scheduled apixaban dose, continuing both warfarin and the parenteral agent for at least 5 days until INR ≥2.0 for at least 24 hours. 1, 2

Transition Protocol

Initial Steps

• Discontinue apixaban and at the exact time the next apixaban dose would have been due, simultaneously start both warfarin and a parenteral anticoagulant 1, 2

• Start warfarin at the usual initial dose: 5 mg daily (or 2.5 mg if liver disease or interacting medications are present) 1

• Do not use a loading dose of warfarin, as the expected maintenance dose is more appropriate and safer 3

Parenteral Anticoagulant Bridge

You must use a parenteral anticoagulant because apixaban affects INR measurements, making initial INR values unreliable for determining appropriate warfarin dosing 2. Choose one of the following options:

LMWH options: 1

• Dalteparin 200 units/kg subcutaneously daily, OR
• Enoxaparin 1 mg/kg subcutaneously every 12 hours

UFH options: 1

• IV: 80 units/kg bolus, then 18 units/kg/hour infusion (target aPTT 2-2.5× control), OR
• Subcutaneous: 333 units/kg loading dose, then 250 units/kg every 12 hours

Monitoring During Transition

• Check INR daily during the transition period 1

• Obtain baseline labs before transition: CBC, PT, aPTT, and renal/hepatic function 1

• Assess for bleeding risk factors: concomitant antiplatelet agents or NSAIDs that increase bleeding risk 1

When to Stop the Parenteral Anticoagulant

Both of the following criteria must be met: 1

1. At least 5 days of overlap therapy with warfarin and parenteral anticoagulant completed
2. INR ≥2.0 for at least 24 hours (target INR 2.0-3.0)

Special Considerations for High-Risk Patients

• For patients at very high thrombotic risk (e.g., recent VTE, mechanical heart valve, severe hypercoagulable state), ensure absolutely no gap in anticoagulation coverage by starting the parenteral agent at the exact time the next apixaban dose would have been due 1

• Monitor renal function during the transition, as changes in kidney function affect both apixaban clearance and warfarin dosing requirements 1

Common Pitfalls to Avoid

• Do not rely on INR measurements during the first few days of transition, as apixaban interferes with INR testing 2

• Do not stop the parenteral anticoagulant prematurely before meeting both the 5-day minimum overlap AND therapeutic INR criteria 1

• Do not use a warfarin loading dose, as this increases bleeding risk without achieving therapeutic anticoagulation more safely 3

• Do not allow any gap in anticoagulation coverage, especially in high-risk patients 1

Ongoing Warfarin Management

• After stopping the parenteral anticoagulant, continue INR monitoring initially twice or three times weekly during the first 2 weeks, then once weekly, and eventually every 4 weeks once stable 3

• Target INR range is 2.0-3.0 for most indications 3, 1

• Continue warfarin for the duration appropriate to the indication: minimum 3 months for VTE, indefinite for atrial fibrillation or recurrent VTE 1