What is the dosage of apixaban for atrial fibrillation?

Apixaban Dosing for Atrial Fibrillation

The standard recommended dose of apixaban for atrial fibrillation is 5 mg taken orally twice daily, with a reduced dose of 2.5 mg twice daily required for patients who have at least two of the following characteristics: age ≥80 years, body weight ≤60 kg, or serum creatinine ≥1.5 mg/dL. 1, 2, 3

Standard Dosing Algorithm

1. Standard dose: 5 mg twice daily

   • For most patients with non-valvular atrial fibrillation
   • Demonstrated superior efficacy compared to warfarin with:
     • 21% reduction in stroke or systemic embolism
     • 31% reduction in major bleeding
     • 11% reduction in all-cause mortality 2

2. Reduced dose: 2.5 mg twice daily

   • Required when patient has ≥2 of these criteria:
     • Age ≥80 years
     • Body weight ≤60 kg
     • Serum creatinine ≥1.5 mg/dL 1, 3
   • Also recommended for patients with severe renal impairment (CrCl 15-29 mL/min) 2

Special Populations

Renal Function Considerations

• Unlike other DOACs, apixaban can be used across the spectrum of renal function, including:
  • Patients with end-stage renal disease
  • Patients on hemodialysis 1, 2
• No dose adjustment needed for mild to moderate renal impairment when used alone 1

Elderly Patients

• Age alone does not warrant dose reduction unless combined with other factors
• Studies show the 5 mg twice daily dose remains safe and effective in elderly patients with only one dose-reduction criterion 4

Common Dosing Errors to Avoid

• Inappropriate dose reduction is common in clinical practice, with studies showing up to 60.8% of patients receiving reduced doses without meeting criteria 5
• Underdosing can compromise stroke prevention efficacy
• Using only one criterion for dose reduction when two are required 4

Perioperative Management

• Discontinue apixaban at least 48 hours before elective surgery with moderate/high bleeding risk
• Discontinue at least 24 hours before procedures with low bleeding risk
• Resume once adequate hemostasis is established 3

Drug Interactions

• Monitor for interactions with strong inhibitors of both CYP3A4 and P-glycoprotein
• No routine coagulation monitoring required 2

Missed Dose Instructions

• If a dose is missed, take as soon as possible on the same day
• Resume twice-daily schedule
• Do not double the dose to make up for a missed dose 3

Apixaban has demonstrated significant benefits in reducing stroke, systemic embolism, and mortality while maintaining a favorable bleeding profile compared to warfarin, making it an excellent choice for stroke prevention in atrial fibrillation when dosed appropriately 2.