What is the recommended dosing of Eliquis (apixaban) compared to Pradaxa (dabigatran) for patients with non-valvular atrial fibrillation?

Eliquis vs Pradaxa Dosing for Atrial Fibrillation

For nonvalvular atrial fibrillation, Eliquis (apixaban) is dosed at 5 mg twice daily (reduced to 2.5 mg twice daily if ≥2 dose-reduction criteria are met), while Pradaxa (dabigatran) is dosed at 150 mg twice daily (or 110 mg twice daily where available for high bleeding risk patients). 1, 2, 3

Standard Dosing Regimens

Eliquis (Apixaban)

• Standard dose: 5 mg orally twice daily for most patients with nonvalvular atrial fibrillation 2, 4, 3
• Reduced dose: 2.5 mg twice daily only when the patient meets at least TWO of the following criteria: 3
  • Age ≥80 years
  • Body weight ≤60 kg
  • Serum creatinine ≥1.5 mg/dL

Pradaxa (Dabigatran)

• Standard dose: 150 mg orally twice daily for patients with CrCl >30 mL/min 1
• Lower dose: 110 mg twice daily (where available) for patients at high risk of bleeding 1
• Reduced dose: 75 mg twice daily may be considered for CrCl 15-30 mL/min, though safety and efficacy are not established 1

Key Dosing Differences

The critical distinction is that apixaban requires TWO dose-reduction criteria to be met simultaneously, while dabigatran dosing is primarily driven by renal function and bleeding risk assessment. 2, 3

Renal Function Considerations

Apixaban:

• Can be used across a wide range of renal function, including severe impairment (CrCl 15-30 mL/min) 3
• For end-stage renal disease on hemodialysis: start with 5 mg twice daily, reduce to 2.5 mg twice daily only if age ≥80 years OR body weight ≤60 kg 2, 3
• Contraindicated if CrCl <15 mL/min and NOT on dialysis 2

Dabigatran:

• Not recommended for patients with CrCl <30 mL/min in most guidelines 1
• For CrCl 15-30 mL/min, 75 mg twice daily may be considered but lacks established safety data 1
• Should not be used in more severe renal failure 1

Efficacy and Safety Profile

Stroke Prevention

• Dabigatran 150 mg twice daily is the only NOAC dose with superior efficacy compared to warfarin for stroke prevention (HR 0.66,95% CI 0.53-0.82) 1
• Apixaban 5 mg twice daily demonstrated a 21% reduction in stroke or systemic embolism compared to warfarin (HR 0.79,95% CI 0.66-0.95) 1, 2, 3

Bleeding Risk

• Apixaban showed a 31% reduction in major bleeding compared to warfarin (2.1% vs 3.1% per year) 1, 2
• Dabigatran 150 mg had similar major bleeding rates to warfarin (3.1% vs 3.4%) 1
• For patients with prior GI bleeding, apixaban or dabigatran 110 mg are preferable as they are not associated with increased GI bleeding compared to warfarin 1

Clinical Decision Algorithm

For high stroke risk patients (high CHADS₂ score):

• Consider dabigatran 150 mg twice daily as it is the only agent with superior stroke prevention efficacy compared to warfarin 1
• However, bleeding risk must be carefully assessed 1

For high bleeding risk patients:

• Prefer apixaban 5 mg twice daily (with dose reduction if criteria met), edoxaban, or dabigatran 110 mg (where available) as all demonstrate significantly less major bleeding than warfarin 1
• Apixaban specifically showed the lowest major bleeding rates in indirect comparisons 5

For patients with moderate renal impairment (CrCl 30-50 mL/min):

• Apixaban is preferred as it can be safely used with standard dosing algorithm 3
• Dabigatran becomes more problematic as renal function declines 1

For patients with severe renal impairment (CrCl 15-30 mL/min):

• Apixaban is the clear choice as it can be used with appropriate dose adjustment 2, 3
• Dabigatran should generally be avoided 1

Common Pitfalls to Avoid

Inappropriate apixaban dose reduction: Approximately 40% of elderly patients receive inappropriately reduced doses of apixaban 6. Do not reduce to 2.5 mg twice daily unless the patient meets at least TWO dose-reduction criteria - underdosing increases thromboembolic risk 4, 3

Overlooking renal function: Both agents require careful renal assessment before initiation and at least annually thereafter, with more frequent monitoring if CrCl 30-50 mL/min 3

Dosing frequency adherence: Dabigatran and apixaban are both twice-daily medications, which may affect adherence differently than once-daily alternatives 7. Missing a dose has significant anticoagulation implications 7

Assuming lower dose is always safer: The reduced apixaban dose (2.5 mg twice daily) maintains efficacy when appropriately prescribed, but inappropriate dose reduction compromises stroke prevention without necessarily reducing bleeding risk 4, 8