What is the recommended use and dosage of Rivaroxaban (Xarelto) for thromboembolic disorders?

Rivaroxaban Dosing for Thromboembolic Disorders

For thromboembolic disorders, rivaroxaban should be dosed at 15 mg orally twice daily with food for the first 21 days followed by 20 mg daily with food for continued treatment of venous thromboembolism (VTE). 1

Initial Treatment Phase

The dosing regimen for rivaroxaban in thromboembolic disorders follows a specific pattern:

• Acute VTE treatment (first 21 days): 15 mg orally twice daily with food 1
• Maintenance treatment (after 21 days): 20 mg orally once daily with food 1

This dosing schedule was specifically designed to provide strong anticoagulation during the acute phase when thrombus burden is highest, followed by an appropriate maintenance dose to prevent recurrence.

Secondary Prevention After Initial Therapy

After completing at least 6 months of initial therapy, dosing options include:

• Continue 20 mg orally daily with food, OR
• Reduce to 10 mg orally daily with or without food 1

The American Society of Hematology provides a conditional recommendation that either the standard dose (20 mg daily) or the reduced dose (10 mg daily) may be used for secondary prevention of VTE after the initial 6-month treatment period 1.

Important Administration Considerations

• Food requirement: The 15 mg and 20 mg doses must be taken with food to maximize absorption 2
• Missed doses:
  • For twice-daily dosing (15 mg): Take immediately to ensure 30 mg total daily intake; two 15 mg tablets may be taken at once if needed 2
  • For once-daily dosing (20 mg or 10 mg): Take the missed dose immediately on the same day; do not double the dose 2

Special Populations and Considerations

Renal Function

• Severe renal impairment (CrCl <30 mL/min): Rivaroxaban should be avoided 1
• Moderate renal impairment (CrCl 30-50 mL/min): Use with caution 1

Hepatic Function

• Avoid in patients with hepatic disease associated with coagulopathy 1

Drug Interactions

• Avoid concomitant use with azole-antimycotics or HIV protease inhibitors 1
• P-glycoprotein interactions should be considered when prescribing 3

Transitioning Between Anticoagulants

From Rivaroxaban to Warfarin

• For adult patients: Discontinue rivaroxaban and begin both parenteral anticoagulant and warfarin when the next rivaroxaban dose would have been taken 2
• For pediatric patients: Continue rivaroxaban for at least 2 days after first warfarin dose, then check INR prior to next scheduled rivaroxaban dose 2

From Other Anticoagulants to Rivaroxaban

• From parenteral anticoagulants: Start rivaroxaban 0-2 hours before next scheduled dose of the parenteral agent 2
• From continuous infusion heparin: Stop infusion and start rivaroxaban at the same time 2

Perioperative Management

• Discontinue rivaroxaban at least 24 hours before elective procedures to reduce bleeding risk 2
• Restart after adequate hemostasis has been established 2

Clinical Pitfalls to Avoid

1. Incorrect dosing: Using the atrial fibrillation dose (15 mg daily) instead of the VTE-specific dose (20 mg daily) for maintenance treatment 1

2. Inadequate patient education: Patients must understand the importance of taking the 15 mg and 20 mg doses with food to ensure proper absorption 2

3. Inappropriate monitoring: Unlike warfarin, routine coagulation monitoring (PT/INR) is not required or recommended for rivaroxaban 1

4. Failure to consider drug interactions: Rivaroxaban has fewer drug interactions than warfarin but still has important interactions with P-glycoprotein and CYP3A4 inhibitors/inducers 3

5. Improper transitioning between anticoagulants: Following specific protocols when switching to or from rivaroxaban is essential to maintain adequate anticoagulation 2