Transitioning from Eliquis (Apixaban) to Coumadin (Warfarin)
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 the parenteral agent and warfarin for at least 5 days until INR ≥2.0 for at least 24 hours, then discontinue the parenteral bridge. 1
Critical Transition Protocol
Timing and Initiation
- Discontinue apixaban and immediately start both warfarin and a parenteral anticoagulant at the exact time the next apixaban dose would have been due 1, 2
- Do not use a loading dose of warfarin; the expected maintenance dose (typically 5 mg daily) is more appropriate and safer 1
- Never start warfarin alone without bridging, as it takes 5-7 days to achieve therapeutic anticoagulation and initially causes a transient hypercoagulable state by depleting protein C before depleting clotting factors 1
Parenteral Bridge Options
Low Molecular Weight Heparin (LMWH):
- Dalteparin 200 units/kg subcutaneously daily, OR
- Enoxaparin 1 mg/kg subcutaneously every 12 hours 1
Unfractionated Heparin (UFH):
- IV bolus of 80 units/kg followed by infusion of 18 units/kg/hour, OR
- Subcutaneous loading dose of 333 units/kg followed by 250 units/kg every 12 hours 1
Duration of Bridge Therapy
- Continue both the parenteral anticoagulant and warfarin for at least 5 days AND until INR ≥2.0 for at least 24 hours 1
- Once INR is therapeutic (≥2.0) for 24 hours and at least 5 days have passed, discontinue the parenteral agent 1
Monitoring Requirements
During Transition Period
- Obtain baseline labs before transition: complete blood count (CBC), prothrombin time (PT), activated partial thromboplastin time (aPTT), and renal/hepatic function 1
- Daily INR monitoring during the transition period 1
- Monitor renal function during transition, as changes in kidney function affect both apixaban clearance and warfarin dosing requirements 1
Long-Term INR Monitoring
- Target INR range: 2.0-3.0 for most indications 1
- Initially check INR twice or three times weekly during the first 2 weeks 1
- Then once weekly after stabilization 1
- Eventually every 4 weeks once stable 1
Special Considerations for High-Risk Patients
Patients Requiring Absolute Anticoagulation Coverage
For patients at very high thrombotic risk (recent VTE, mechanical heart valve, or 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
- This is critical because apixaban has a half-life of 9-14 hours, meaning missed doses leave patients without protection 3
Renal Dysfunction Considerations
- For end-stage CKD on dialysis, warfarin is preferred over apixaban if anticoagulation is necessary 1
- Monitor renal function closely as it affects both drug clearances 1
Critical Pitfalls to Avoid
Common Errors
- Never start warfarin alone without bridging - this creates a dangerous gap in coverage and initial hypercoagulable state 1
- Do not discontinue the parenteral bridge too early - must continue for at least 5 days AND until INR ≥2.0 for 24 hours 1
- Avoid using warfarin loading doses - use maintenance dosing from the start 1
Concomitant Medications
- Consider whether antiplatelet agents or NSAIDs that increase bleeding risk can be safely discontinued during the transition 1
- The duration of action of irreversible antiplatelet agents (aspirin, clopidogrel, prasugrel) means temporary discontinuation may not have clinical effect for several days 4