What is the protocol for transitioning from warfarin to Xarelto (rivaroxaban)

Protocol for Transitioning from Warfarin to Rivaroxaban (Xarelto)

When transitioning patients from warfarin to rivaroxaban, discontinue warfarin and start rivaroxaban as soon as the International Normalized Ratio (INR) is below 3.0 in adults.

Step-by-Step Transition Protocol

Initial Assessment

• Verify the indication for anticoagulation therapy
• Confirm rivaroxaban is appropriate for the patient's condition
• Check for contraindications to rivaroxaban:
  • Mechanical heart valves (contraindicated) 1
  • Antiphospholipid syndrome (especially triple-positive patients) 2
  • Severe renal impairment (CrCl <15 mL/min)

Transition Process

1. Stop warfarin and check INR daily or every other day
2. Start rivaroxaban when INR <3.0:
   • For atrial fibrillation: 20 mg once daily with food
   • For venous thromboembolism: 15 mg twice daily with food for 21 days, then 20 mg once daily 3
   • Dose adjustments for renal impairment:
     • For CrCl 15-50 mL/min: 15 mg once daily for atrial fibrillation
     • Avoid use if CrCl <15 mL/min

Monitoring During Transition

• No routine coagulation monitoring is required for rivaroxaban
• INR values will be unreliable after starting rivaroxaban and should not be used to assess rivaroxaban's anticoagulant effect
• Monitor for signs of bleeding or thrombosis during the transition period

Special Considerations

Renal Function

• Assess renal function before transition
• For patients with moderate renal impairment (CrCl 15-50 mL/min), use reduced dosing
• Avoid rivaroxaban in severe renal impairment (CrCl <15 mL/min)

High-Risk Patients

• For patients at high thrombotic risk:
  • Consider more frequent INR monitoring during the transition period
  • Minimize the time between stopping warfarin and starting rivaroxaban
  • If INR falls below therapeutic range before reaching <3.0, consider bridging with parenteral anticoagulant

Medication Interactions

• Assess for medications that interact with rivaroxaban:
  • Strong CYP3A4 and P-glycoprotein inhibitors or inducers
  • Other anticoagulants, antiplatelets, or NSAIDs

Common Pitfalls and Caveats

1. Do not overlap warfarin and rivaroxaban therapy - unlike transitioning to warfarin, no overlap period is needed when switching from warfarin to rivaroxaban 3

2. Avoid rivaroxaban in patients with mechanical heart valves - rivaroxaban is contraindicated in this population 1

3. Be cautious in patients with antiphospholipid syndrome - rivaroxaban has been associated with increased thromboembolic events compared to warfarin in high-risk triple-positive patients 2

4. Ensure patient adherence - unlike warfarin, rivaroxaban:

   • Has no routine monitoring requirement
   • Has a shorter half-life (missed doses can quickly lead to loss of anticoagulation)
   • Must be taken with food (rivaroxaban 15 mg and 20 mg doses)

5. Provide clear discharge instructions - include indication, dosing, duration of therapy, and follow-up plans to ensure safe transitions of care 4

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