What is the dosage equivalent of Xarelto (rivaroxaban) to Eliquis (apixaban)?

Dosage Equivalence Between Xarelto (Rivaroxaban) and Eliquis (Apixaban)

There is no direct dosage equivalence between Xarelto (rivaroxaban) and Eliquis (apixaban) as they have different pharmacokinetic profiles and dosing regimens, but for atrial fibrillation, rivaroxaban 20 mg once daily is generally considered therapeutically equivalent to apixaban 5 mg twice daily.

Pharmacokinetic Differences

The two medications have significant differences that prevent a simple milligram-to-milligram conversion:

• Half-life:

  • Apixaban: 12 hours 1
  • Rivaroxaban: 5-9 hours 1

• Bioavailability:

  • Apixaban: 50% 2
  • Rivaroxaban: 60-80% 1

• Renal excretion:

  • Apixaban: 27% renal, 73% biliary and intestinal 1
  • Rivaroxaban: 66% renal, 28% feces 1

Standard Dosing in Atrial Fibrillation

Rivaroxaban (Xarelto)

• Standard dose: 20 mg once daily 1
• Reduced dose: 15 mg once daily for CrCl 15-50 mL/min 1

Apixaban (Eliquis)

• Standard dose: 5 mg twice daily 1, 3
• Reduced dose: 2.5 mg twice daily if patient has at least 2 of the following: age ≥80 years, weight ≤60 kg, or serum creatinine ≥1.5 mg/dL 1, 3

Comparative Effectiveness and Safety

Recent evidence suggests important differences in clinical outcomes between these medications:

• A large retrospective cohort study of Medicare beneficiaries found that rivaroxaban was associated with increased risk of major ischemic and hemorrhagic events compared to apixaban (HR 1.18,95% CI 1.12-1.24) 4

• Meta-analysis data indicates apixaban is associated with:

  • Lower risk of stroke/systemic embolism (HR 0.88,95% CI 0.81-0.95)
  • Lower risk of major bleeding (HR 0.62,95% CI 0.56-0.69)
  • Lower risk of gastrointestinal bleeding (HR 0.57,95% CI 0.50-0.64) compared to rivaroxaban 5

Special Considerations for Switching Between Agents

When switching between these medications:

1. From rivaroxaban to apixaban:

   • Discontinue rivaroxaban
   • Start apixaban at the time the next rivaroxaban dose would have been taken

2. From apixaban to rivaroxaban:

   • Discontinue apixaban
   • Start rivaroxaban at the time the next apixaban dose would have been taken

Perioperative Management Differences

For elective procedures with significant bleeding risk:

• Apixaban: Discontinue 48 hours before procedure 3
• Rivaroxaban: Discontinue 48 hours before procedure 3

For procedures with low bleeding risk:

• For both medications, discontinue 24 hours before the procedure 1

Important Caveats

• No direct conversion: There is no FDA-approved conversion formula between these medications
• Renal function: Apixaban is less dependent on renal clearance than rivaroxaban, making it potentially safer in patients with renal impairment
• Bleeding risk: Multiple studies show apixaban has a more favorable bleeding profile compared to rivaroxaban 4, 6, 5
• Dosing frequency: Rivaroxaban is once daily while apixaban is twice daily, which may affect adherence

Clinical Decision-Making

When deciding between these agents or switching from one to another, consider:

1. Renal function (apixaban preferred in renal impairment)
2. Bleeding risk (apixaban associated with lower bleeding rates)
3. Medication adherence (once-daily rivaroxaban may be easier for some patients)
4. Comorbidities and concomitant medications (drug-drug interactions)

The choice between these medications should be based on these clinical factors rather than attempting to find a direct dosage equivalence.