Rivaroxaban Dosing for New Cardioembolic Stroke
For a new cardioembolic stroke in the setting of atrial fibrillation, use rivaroxaban 20 mg once daily with the evening meal (or 15 mg once daily if creatinine clearance is 30-49 mL/min). 1, 2
Standard Dosing for Stroke Prevention in Atrial Fibrillation
The established stroke prevention dose is rivaroxaban 20 mg once daily, taken with food (specifically the evening meal) to ensure adequate absorption and consistent anticoagulant effect. 1, 2 This dosing was validated in the ROCKET-AF trial, which demonstrated non-inferiority to warfarin for preventing stroke and systemic embolism in patients with nonvalvular atrial fibrillation. 1, 3
Lower doses are not recommended unless specifically indicated by renal impairment or other tested criteria. 1 The guideline explicitly states that NOACs should be used at established stroke prevention doses, not at reduced doses. 1
Renal Function-Based Dose Adjustment
If creatinine clearance is 30-49 mL/min, reduce the dose to 15 mg once daily. 1, 2, 4 This dose adjustment was specifically tested in the ROCKET-AF trial and showed consistent treatment effects compared to the standard 20 mg dose in patients with normal renal function. 4
Rivaroxaban is contraindicated if creatinine clearance is <30 mL/min. 1
Critical Timing Consideration
Do not confuse this with embolic stroke of undetermined source (ESUS). For ESUS specifically, rivaroxaban 15 mg daily was tested in the NAVIGATE ESUS trial and was NOT superior to aspirin, with significantly higher bleeding risk (hazard ratio 2.72). 5 However, your question specifies a cardioembolic stroke, which implies a known cardioembolic source (atrial fibrillation), not ESUS.
Monitoring Requirements
- Assess renal function before initiating therapy and periodically during treatment, especially in elderly patients or those with fluctuating renal function. 2
- No routine coagulation monitoring is required, unlike warfarin. 2
Common Pitfall to Avoid
Do not use the DVT/PE dosing regimen (15 mg twice daily for 21 days, then 20 mg once daily) for stroke prevention. 6 That regimen is specifically for acute venous thromboembolism treatment, not cardioembolic stroke prevention. For atrial fibrillation-related stroke prevention, use the single daily dose from the outset. 1, 2