Apixaban Dosing for Atrial Fibrillation

Standard Dosing Algorithm

• The American College of Cardiology recommends a standard dose of apixaban of 5 mg orally twice daily for patients with 0 or 1 dose-reduction criteria, with a reduced dose of 2.5 mg twice daily only when at least 2 of the following 3 criteria are met: age ≥80 years, body weight ≤60 kg, or serum creatinine ≥1.5 mg/dL 1, 2, 3
• The European Heart Society supports the use of a three-criteria rule to determine the dose of apixaban, including age ≥80 years, body weight ≤60 kg, and serum creatinine ≥1.5 mg/dL 1, 2, 3

Renal Function Considerations

• The American College of Cardiology recommends applying the standard three-criteria dosing algorithm for patients with CrCl >25 mL/min 1
• For patients with CrCl 15-29 mL/min, the recommended dose is 2.5 mg twice daily, which automatically meets dose-reduction criteria 1
• For patients with end-stage renal disease on hemodialysis, the recommended starting dose is 5 mg twice daily, with a reduction to 2.5 mg twice daily if age ≥80 years or body weight ≤60 kg 1, 5

Clinical Evidence Supporting These Recommendations

• The ARISTOTLE trial demonstrated a 21% reduction in stroke or systemic embolism compared to warfarin (HR 0.79, 95% CI 0.66-0.95) 5
• The ARISTOTLE trial also showed a 31% reduction in major bleeding compared to warfarin 5

Monitoring Requirements

• The American College of Cardiology recommends assessing renal function at least annually, and monitoring every 3-6 months if CrCl <60 mL/min or evidence of declining renal function 1, 5
• No routine coagulation monitoring (INR) is required, but patients should be monitored for signs of bleeding or thromboembolism clinically 5, 4

Perioperative Management

• When interrupting apixaban for surgery or procedures, the American College of Cardiology recommends holding for 1 day (24 hours) before low bleeding risk procedures, and 2 days (48 hours) before high bleeding risk procedures, with consideration of holding for an additional 1-3 days for patients with CrCl <25 mL/min 1

Switching from Warfarin to Apixaban

• The American College of Cardiology recommends discontinuing warfarin, starting apixaban when INR drops below 2.0, and applying the standard three-criteria dosing algorithm to determine the dose of apixaban 1, 4

Drug Interactions Requiring Dose Adjustment

• The American College of Cardiology recommends reducing apixaban to 2.5 mg twice daily when using combined P-glycoprotein and strong CYP3A4 inhibitors in patients otherwise receiving 5 mg twice daily, such as ketoconazole 1, 4