What dose of Eliquis (apixaban) is equivalent to 2.5mg of warfarin for a patient with pulmonary embolism (PE)?

Equivalent Apixaban Dosing for Pulmonary Embolism Treatment

For a patient currently taking warfarin 2.5mg for pulmonary embolism (PE), the equivalent apixaban dosing regimen is 10mg twice daily for the first 7 days followed by 5mg twice daily for long-term treatment.

Initial Treatment Phase

• Apixaban should be initiated with a loading dose of 10mg twice daily for the first 7 days of therapy for PE treatment 1
• Unlike warfarin, apixaban does not require initial parenteral anticoagulation and can be started immediately upon diagnosis 1
• This higher initial dose ensures rapid therapeutic anticoagulation for the acute phase of PE treatment 2

Maintenance Phase

• After the initial 7-day period, the dose should be reduced to 5mg twice daily for continued treatment 2, 1
• This maintenance dose should be continued for at least 3 months for PE treatment 1
• For patients with unprovoked PE or ongoing risk factors, extended anticoagulation beyond 3 months may be necessary 1

Dosing Considerations

• Apixaban dosing for PE is standardized and not INR-dependent like warfarin 2
• The 2.5mg twice daily reduced dose of apixaban is not equivalent to warfarin 2.5mg and is only recommended for extended secondary prevention after completing at least 6 months of initial therapy 2
• The American Society of Hematology guidelines suggest that after 6 months of initial therapy, either 5mg twice daily or 2.5mg twice daily can be considered for extended secondary prevention 2

Efficacy and Safety Comparison

• Apixaban has been shown to be noninferior to warfarin for PE treatment with significantly less bleeding risk 3, 4
• In real-world studies, apixaban demonstrated 27-39% lower risk of major bleeding and 25-39% lower risk of recurrent VTE compared to warfarin 4
• Apixaban has a more predictable anticoagulant effect without the need for routine monitoring that warfarin requires 5

Special Considerations

• Apixaban should be used with caution in patients with severe renal impairment (creatinine clearance <30 mL/min) 1
• Dose adjustment may be necessary for patients with specific characteristics such as age ≥80 years, body weight ≤60 kg, or serum creatinine ≥1.5 mg/dL 2
• Unlike warfarin, which requires frequent INR monitoring (initially every 1-2 days), apixaban does not require routine coagulation monitoring 2

Common Pitfalls to Avoid

• Do not continue the initial higher dose (10mg twice daily) beyond the first 7 days as this increases bleeding risk 1
• Do not administer parenteral anticoagulants when initiating apixaban, as this can increase bleeding risk 1
• Do not use the 2.5mg twice daily dose for initial PE treatment as this is inadequate for acute management 2, 1
• Avoid assuming direct dose equivalence between warfarin and apixaban as they have different mechanisms of action and dosing strategies 5