Yes, rivaroxaban 2.5 mg twice daily should be discontinued when starting enoxaparin 40 mg daily for DVT prophylaxis
The patient is already receiving therapeutic antithrombotic therapy with rivaroxaban 2.5 mg twice daily plus aspirin for peripheral arterial disease, which provides both cardiovascular and venous thromboembolism protection—adding enoxaparin would create dangerous dual anticoagulation without additional benefit.
Rationale for Discontinuation
The rivaroxaban 2.5 mg twice daily regimen (combined with aspirin) is specifically designed for PAD patients to reduce major adverse cardiovascular events and major adverse limb events 1, 2. This dose, while lower than treatment doses for acute VTE, still provides anticoagulant activity through factor Xa inhibition 3.
Adding enoxaparin 40 mg daily on top of rivaroxaban would result in:
- Dual anticoagulation with overlapping mechanisms (both inhibit the coagulation cascade)
- Significantly increased bleeding risk without proven incremental benefit
- Violation of FDA labeling, which warns that "concomitant use of other drugs that impair hemostasis increases the risk of bleeding. These include...other antithrombotic agents" 3
The Correct Approach
Continue rivaroxaban 2.5 mg twice daily (with aspirin) as the sole antithrombotic regimen. This provides:
Adequate VTE prophylaxis: The MAGELLAN trial demonstrated that rivaroxaban 10 mg daily (a higher dose than your patient is receiving) was effective for VTE prophylaxis in acutely ill medical patients 3. While your patient receives 2.5 mg twice daily (5 mg total daily), this still provides anticoagulant effect.
Continued PAD protection: Discontinuing rivaroxaban would eliminate the proven cardiovascular and limb protection in PAD patients, with guidelines specifically warning that "premature discontinuation of any oral anticoagulant, including XARELTO, in the absence of adequate alternative anticoagulation increases the risk of thrombotic events" 3.
Avoidance of bleeding complications: The FDA label explicitly notes increased bleeding risk with combined anticoagulants 3, and the 2024 ESC guidelines emphasize careful bleeding risk assessment when using rivaroxaban in PAD 2.
Important Caveats
If the clinical team believes the current rivaroxaban dose is insufficient for VTE prophylaxis in this immobile patient, the alternative would be:
- Temporarily discontinue rivaroxaban 2.5 mg twice daily
- Start therapeutic anticoagulation with enoxaparin 1 mg/kg twice daily (treatment dose, not prophylactic 40 mg) OR rivaroxaban 15 mg twice daily for 3 weeks then 20 mg daily (standard VTE treatment dosing)
- This approach is supported by evidence showing safe transitions between enoxaparin and rivaroxaban 4, 5
However, this creates a new problem: loss of the proven PAD protection from the rivaroxaban 2.5 mg + aspirin regimen, and the need to eventually transition back after the immobility period resolves.
The risk of rebound hypercoagulability after rivaroxaban withdrawal is real 6, making abrupt discontinuation particularly hazardous in a PAD patient with existing thrombotic risk.
Bottom Line
Do not add enoxaparin 40 mg to existing rivaroxaban 2.5 mg twice daily. The patient is already anticoagulated. If higher-intensity anticoagulation is deemed necessary due to exceptional VTE risk from immobility, switch entirely to treatment-dose anticoagulation (not prophylactic dose), but recognize this sacrifices the specific PAD benefits of the current regimen 1, 2.