What is the recommended approach for transitioning from fondaparinux to rivaroxaban (Xarelto) for outpatient Deep Vein Thrombosis (DVT) prophylaxis?

Transitioning from Fondaparinux to Rivaroxaban for Outpatient DVT Prophylaxis

When transitioning from fondaparinux to rivaroxaban for outpatient DVT prophylaxis, rivaroxaban can be started immediately after discontinuing fondaparinux with no overlap period required, as rivaroxaban has demonstrated non-inferiority to fondaparinux in efficacy with a similar safety profile. 1, 2

Evidence Supporting Direct Transition

• Rivaroxaban has been directly compared to fondaparinux in the SURPRISE trial, which demonstrated non-inferiority for the treatment of superficial vein thrombosis with similar efficacy outcomes (3% vs 2% composite endpoint) 2
• The direct transition from fondaparinux to rivaroxaban is supported by their similar mechanisms as factor Xa inhibitors, with rivaroxaban being an oral direct factor Xa inhibitor and fondaparinux being a parenteral indirect factor Xa inhibitor 1
• Unlike transitions to dabigatran or edoxaban which require parenteral anticoagulation first, rivaroxaban can be used as a single-drug regimen without the need for initial parenteral anticoagulation 3

Dosing Protocol for Transition

• For DVT prophylaxis, start rivaroxaban at 10 mg once daily after discontinuing fondaparinux 1, 4
• For therapeutic treatment of established DVT, start rivaroxaban at 15 mg twice daily for the first 21 days, then transition to 20 mg once daily 4, 3
• Administer rivaroxaban with food to improve absorption, especially during the initial treatment phase 4

Special Considerations

• For patients with superficial vein thrombosis >5 cm in length or extending above the knee, prophylactic dosing of rivaroxaban 10 mg daily for 45 days is appropriate 1, 2
• For superficial vein thrombosis within 3 cm of the saphenofemoral junction, therapeutic dosing of rivaroxaban is recommended for at least 3 months 1
• In patients with cancer-associated thrombosis, rivaroxaban has demonstrated efficacy similar to standard therapy with potentially lower rates of major bleeding 4

Monitoring After Transition

• No routine coagulation monitoring is required with rivaroxaban, unlike vitamin K antagonists 4, 3
• Baseline laboratory testing should include CBC, renal and hepatic function panel, aPTT, and PT/INR 4
• Avoid rivaroxaban in patients with severe renal impairment (creatinine clearance <15 mL/min) 4
• For patients with gastric or gastroesophageal tumors, consider continuing fondaparinux or switching to apixaban instead, as these patients have increased risk of hemorrhage with rivaroxaban 1

Clinical Outcomes

• The SURPRISE trial showed that rivaroxaban was non-inferior to fondaparinux for preventing thromboembolic complications with no major bleeding events in either treatment group 2
• Rivaroxaban offers advantages over fondaparinux including oral administration (versus subcutaneous injection), potentially improving patient adherence and reducing treatment burden 1, 2
• Extended treatment with rivaroxaban for isolated distal DVT (additional 6 weeks after initial 6-week treatment) has been shown to reduce recurrent venous thromboembolism without increasing bleeding risk 5

By following this approach to transitioning from fondaparinux to rivaroxaban, clinicians can maintain effective DVT prophylaxis while potentially improving patient convenience and adherence.