Transitioning from Heparin to Apixaban for Acute VTE
Yes, you should transition directly to apixaban 10 mg twice daily for 7 days, then 5 mg twice daily, without requiring additional heparin overlap. 1, 2
Direct Transition Protocol
Apixaban can be started immediately after discontinuing heparin without any bridging period. This is a key advantage over warfarin or other DOACs like dabigatran/edoxaban that require 5 days of parenteral lead-in therapy. 3, 2
Specific Dosing Regimen
- Days 1-7: Apixaban 10 mg orally twice daily (loading dose) 1, 2
- Day 8 onwards: Apixaban 5 mg orally twice daily for at least 3 months (provoked VTE) or longer (unprovoked VTE) 1, 4
- Extended therapy (>6 months): Consider reducing to 2.5 mg twice daily for secondary prevention to minimize bleeding risk 3, 1
Evidence Supporting This Approach
The AMPLIFY trial validated this exact regimen, demonstrating that apixaban 10 mg twice daily for 7 days followed by 5 mg twice daily was noninferior to enoxaparin/warfarin for preventing recurrent VTE (2.3% vs 2.7%), with significantly superior safety profile showing major bleeding of only 0.6% versus 1.8% with conventional therapy. 3, 5
This loading dose achieves rapid anticoagulation without requiring initial parenteral anticoagulation, making the transition from your heparin drip straightforward. 1
Critical Exclusion Criteria to Check
Before transitioning, verify the patient does NOT have:
- Severe renal impairment: CrCl <15 mL/min (absolute contraindication); use caution if CrCl <25 mL/min 1, 6
- Significant hepatic impairment: Transaminases >2x upper limit of normal or total bilirubin >1.5x upper limit of normal 3, 1
- Active bleeding or high bleeding risk requiring continued monitoring with adjustable anticoagulation 2
Advantages Over Warfarin Transition
Unlike warfarin, which requires 5+ days of heparin overlap until INR reaches 2-3, apixaban's loading dose provides immediate therapeutic anticoagulation. 3 This eliminates:
- Extended hospitalization for heparin monitoring
- INR monitoring requirements
- Risk of subtherapeutic anticoagulation during transition
- Drug-food interactions associated with warfarin
Special Populations
Cancer-associated VTE: DOACs including apixaban are now preferred over LMWH due to better compliance and ease of use, though patients with GI or genitourinary malignancies may have higher bleeding risk. 3 The Caravaggio trial demonstrated non-inferiority of apixaban versus dalteparin in cancer patients. 7
No dose adjustment needed for mild to moderate renal impairment (CrCl ≥15 mL/min), as apixaban has only 27% renal elimination. 6
Common Pitfall to Avoid
Do not confuse VTE dosing with atrial fibrillation dosing. The AF indication has different dose reduction criteria (age ≥80, weight ≤60 kg, or creatinine ≥1.5 mg/dL = 2.5 mg twice daily). For acute VTE, always use the full 10 mg twice daily loading dose regardless of these factors, unless CrCl <25 mL/min. 6