What is the dose of Apixaban for atrial fibrillation or deep vein thrombosis?

Apixaban Dosing for Atrial Fibrillation and Deep Vein Thrombosis

For atrial fibrillation, apixaban is dosed at 5 mg twice daily, with dose reduction to 2.5 mg twice daily for patients with at least two of the following: age ≥80 years, body weight ≤60 kg, or serum creatinine ≥1.5 mg/dL. For DVT treatment, apixaban is dosed at 10 mg twice daily for 7 days followed by 5 mg twice daily. 1

Dosing for Atrial Fibrillation

Standard Dosing

• Standard dose: 5 mg orally twice daily 2, 1
• This dosing has demonstrated superior efficacy compared to warfarin with:
  • 21% relative risk reduction in stroke or systemic embolism 2
  • 31% reduction in major bleeding 2
  • 11% reduction in all-cause mortality 2

Dose Reduction Criteria

Reduce to 2.5 mg twice daily if patient has at least two of the following:

• Age ≥80 years
• Body weight ≤60 kg
• Serum creatinine ≥1.5 mg/dL 2, 1

Special Populations

• End-stage renal disease requiring hemodialysis: 5 mg twice daily, reduce to 2.5 mg twice daily if age ≥80 years or body weight ≤60 kg 2
• Canadian labeling specifies: 2.5 mg twice daily if serum creatinine ≥133 μmol/L and either age ≥80 years or body weight ≤60 kg 2

Dosing for Deep Vein Thrombosis/Pulmonary Embolism

Initial Treatment

• 10 mg orally twice daily for the first 7 days of therapy 2, 1
• Then 5 mg orally twice daily for continued treatment 2, 1

Secondary Prevention

• After at least 6 months of initial therapy, either:
  • Continue 5 mg orally twice daily, or
  • Reduce to 2.5 mg orally twice daily for extended treatment 2, 1

Clinical Considerations

Efficacy and Safety

• In the ARISTOTLE trial, apixaban demonstrated superior efficacy and safety compared to warfarin 2
• Patients with one dose-reduction criterion still showed consistent benefits with the standard 5 mg twice daily dose compared to warfarin 3

Missed Dose Management

• If a dose is missed, take it as soon as possible on the same day
• Resume twice-daily administration schedule
• Do not double the dose to make up for a missed dose 1

Temporary Interruption for Surgery

• Discontinue apixaban at least 48 hours prior to elective surgery with moderate/high bleeding risk
• Discontinue at least 24 hours prior to procedures with low bleeding risk 1

Common Pitfalls to Avoid

1. Inappropriate dose reduction: Studies show that approximately 57% of patients receiving reduced-dose apixaban don't meet the dose reduction criteria 4, 5. This may lead to suboptimal stroke prevention.

2. Failure to adjust dose when criteria change: Regularly reassess patients for changes in weight, age, or renal function that might necessitate dose adjustment.

3. Abrupt discontinuation: Premature discontinuation increases thrombotic risk. If discontinuation is necessary (other than for bleeding), consider alternative anticoagulation 1.

4. Drug interactions: Be aware of potential interactions with drugs affecting CYP3A4 and P-glycoprotein pathways, which may require dose adjustments.

5. Inappropriate use in mechanical heart valves: Apixaban is contraindicated in patients with mechanical heart valves 2.

By following these evidence-based dosing guidelines, clinicians can optimize the benefits of apixaban while minimizing risks in patients with atrial fibrillation or venous thromboembolism.