What is the dosage of Xarelto (rivaroxaban) for stroke prevention in atrial fibrillation?

Rivaroxaban Dosage for Atrial Fibrillation

For stroke prevention in atrial fibrillation, rivaroxaban (Xarelto) should be administered at a dose of 20 mg once daily with the evening meal for patients with normal to mildly impaired renal function (CrCl >50 mL/min), and reduced to 15 mg once daily with the evening meal for patients with moderate to severe renal impairment (CrCl 15-50 mL/min). 1, 2

Standard Dosing Algorithm

1. Normal to mild renal impairment (CrCl >50 mL/min):

   • 20 mg once daily with the evening meal

2. Moderate to severe renal impairment (CrCl 15-50 mL/min):

   • 15 mg once daily with the evening meal

3. End-stage renal disease or dialysis (CrCl <15 mL/min):

   • Not recommended 1

Administration Requirements

• Rivaroxaban must be taken with food, specifically with the evening meal, to ensure adequate absorption 1, 2
• The tablet can be crushed and mixed with applesauce for patients who cannot swallow tablets whole 2
• For patients with NG tubes, the tablet can be crushed and mixed with water before administration 2

Clinical Evidence

Rivaroxaban was evaluated in the ROCKET AF trial, which compared it to warfarin in patients with nonvalvular atrial fibrillation. The trial demonstrated noninferiority for rivaroxaban compared to warfarin for prevention of stroke and systemic embolism 1, 3.

Key findings from clinical trials:

• Rivaroxaban showed similar efficacy to warfarin with HR 0.88 (95% CI, 0.74-1.03) for stroke or systemic embolism 1
• Less intracranial hemorrhage compared to warfarin 1, 3
• Similar rates of major bleeding compared to warfarin, but with less fatal bleeding 1

Special Considerations

Renal Function

• Renal function should be evaluated prior to initiation of rivaroxaban and reassessed at least annually 1
• The reduced dose of 15 mg once daily is specifically for patients with CrCl 15-50 mL/min 1
• Rivaroxaban is not recommended for patients with end-stage CKD or on dialysis due to lack of evidence 1

Drug Interactions

• Concomitant use of dual P-glycoprotein and strong CYP3A4 inducers or inhibitors may require dosing adjustment or avoidance 1

Common Pitfalls to Avoid

1. Inappropriate underdosing: Studies show that rivaroxaban is often prescribed at reduced doses even when not indicated by renal function, which may compromise stroke prevention 4

2. Missing the evening meal requirement: Unlike some other anticoagulants, rivaroxaban must be taken with food, specifically the evening meal, to ensure proper absorption 1, 2

3. Failure to adjust for renal function: Not reducing the dose for patients with moderate renal impairment can increase bleeding risk 1

4. Discontinuation without consultation: Patients should be advised never to discontinue rivaroxaban without first consulting their healthcare provider due to increased stroke risk 2

5. Improper monitoring: While routine coagulation monitoring is not required, renal function should be assessed regularly 1

By following these dosing recommendations, clinicians can optimize the balance between stroke prevention and bleeding risk in patients with atrial fibrillation requiring anticoagulation.