Apixaban Dosing for Atrial Fibrillation
The standard dose of apixaban for stroke prevention in atrial fibrillation is 5 mg orally twice daily, with dose reduction to 2.5 mg twice daily ONLY when the patient meets at least TWO of the following criteria: age ≥80 years, body weight ≤60 kg, or serum creatinine ≥1.5 mg/dL (133 μmol/L). 1, 2
Standard Dosing Regimen
The 5 mg twice daily dose is appropriate for the vast majority of patients with nonvalvular atrial fibrillation, including those with a single dose-reduction criterion such as isolated advanced age, low body weight, or renal dysfunction 3, 4
This dosing was established in the ARISTOTLE trial, which demonstrated a 21% reduction in stroke or systemic embolism compared to warfarin (HR 0.79,95% CI 0.66-0.95), along with a 31% reduction in major bleeding and an 11% reduction in all-cause mortality 2, 4
Critical Dose Reduction Criteria
You must apply the dose reduction criteria correctly—this is where errors commonly occur in clinical practice:
Reduce to 2.5 mg twice daily ONLY when at least TWO of these three criteria are present simultaneously 1, 2:
- Age ≥80 years
- Body weight ≤60 kg
- Serum creatinine ≥1.5 mg/dL (133 μmol/L)
Patients with only ONE dose-reduction criterion should receive the full 5 mg twice daily dose, as they demonstrate consistent efficacy and safety with this regimen compared to warfarin 3, 4
Common pitfall: In real-world practice, approximately 60% of patients receiving the reduced 2.5 mg dose do not actually meet the labeling criteria for dose reduction, with inappropriate underdosing driven by the presence of a single criterion rather than the required two 5
Renal Function Considerations
For patients with CrCl >30 mL/min, apply the standard dosing algorithm above 4, 6
For patients with severe renal impairment (CrCl 15-30 mL/min), use 5 mg twice daily unless ≥2 dose-reduction criteria are met, then use 2.5 mg twice daily 2, 4
For patients with end-stage renal disease on hemodialysis, start with 5 mg twice daily, reducing to 2.5 mg twice daily only if age ≥80 years OR body weight ≤60 kg 4, 7
Apixaban is contraindicated in patients with CrCl <15 mL/min who are NOT on dialysis 1, 4
Administration Details
No loading dose is required when initiating therapy 4
No bridging anticoagulation is needed when starting apixaban 4
Doses should be taken approximately 12 hours apart 1
If a dose is missed, take it as soon as possible on the same day, but do not double the dose 1
Monitoring Requirements
Assess renal function before starting and at least annually thereafter 4, 6
Monitor renal function more frequently (every 3-6 months) if CrCl 30-50 mL/min or if other risk factors for renal deterioration exist 6
Evaluate body weight periodically, particularly in patients near the 60 kg threshold, as weight changes may affect dosing criteria 6
Assess clinically for signs of bleeding or thromboembolism 4