What is the dose of Pradaxa (dabigatran) for atrial fibrillation (AFib)?

Dosage of Pradaxa (Dabigatran) for Atrial Fibrillation

The standard dose of Pradaxa (dabigatran) for atrial fibrillation is 150 mg twice daily for patients with creatinine clearance >30 mL/min, with a reduced dose of 75 mg twice daily for patients with creatinine clearance 15-30 mL/min. 1

Standard Dosing

For most patients with non-valvular atrial fibrillation:

• 150 mg twice daily for patients with CrCl >30 mL/min 2, 1

Dose Adjustments Based on Renal Function

Renal function significantly impacts dabigatran dosing:

• CrCl >30 mL/min: 150 mg twice daily
• CrCl 15-30 mL/min: 75 mg twice daily
• CrCl <15 mL/min or dialysis: Contraindicated 2, 1

Special Considerations for Dose Reduction

Dose reduction to 75 mg twice daily is also required in the following scenarios:

• Patients with CrCl 30-50 mL/min who are taking dronedarone or ketoconazole (P-gp inhibitors) 2, 1
• Patients with severe renal impairment (CrCl 15-30 mL/min) 1, 3

Contraindications

Dabigatran is contraindicated in:

• Patients with mechanical prosthetic heart valves 1
• Patients with CrCl <15 mL/min or on dialysis 2
• Patients with triple-positive antiphospholipid syndrome 1

Clinical Evidence Supporting Dosing

The RE-LY trial established the efficacy and safety of dabigatran in non-valvular AF:

• 150 mg twice daily reduced stroke/systemic embolism by 34% compared to warfarin (1.11% vs 1.71% per year) 2
• This dose showed similar rates of major bleeding compared to warfarin (3.32% vs 3.57% per year) 2
• Significantly reduced rates of hemorrhagic stroke and intracranial bleeding 2

Important Monitoring Considerations

Unlike warfarin, dabigatran does not require routine coagulation monitoring. However:

• Regular monitoring of renal function is essential 4
• Assess for drug interactions, particularly P-glycoprotein inhibitors 1
• Monitor for bleeding complications, especially gastrointestinal bleeding (higher risk with dabigatran 150 mg compared to warfarin) 2

Common Pitfalls to Avoid

1. Failure to adjust dose based on renal function: Renal impairment significantly increases dabigatran exposure and bleeding risk 1

2. Inappropriate discontinuation: Abrupt discontinuation increases thrombotic risk; plan transitions carefully 1

3. Overlooking drug interactions: P-gp inhibitors (dronedarone, ketoconazole) require dose adjustment 1

4. Missing contraindications: Dabigatran should not be used in patients with mechanical heart valves due to increased thrombotic and bleeding risk 1

5. Inadequate patient education: Twice-daily dosing requires good adherence; missed doses can significantly impact efficacy 2

When transitioning from warfarin to dabigatran, discontinue warfarin and start dabigatran when INR is below 2.0 to minimize bleeding risk 1.