Transitioning from Enoxaparin to Apixaban
When switching from enoxaparin to apixaban for VTE treatment, discontinue enoxaparin and immediately start apixaban at 10 mg orally twice daily for 7 days, followed by 5 mg orally twice daily—no overlap or bridging period is required. 1, 2
Standard Dosing Protocol
The transition is straightforward and does not require the 5-10 day parenteral anticoagulation lead-in that other DOACs like dabigatran and edoxaban require 1:
- Stop enoxaparin at the time of the next scheduled dose
- Start apixaban immediately at 10 mg orally twice daily for the first 7 days 1, 2
- Continue with 5 mg orally twice daily after the initial 7-day period for at least 3 months 1, 2
- Extended therapy beyond 6 months: Either continue 5 mg twice daily or consider dose reduction to 2.5 mg twice daily 1, 2
This represents a key advantage of apixaban over edoxaban and dabigatran, which both require at least 5-10 days of parenteral anticoagulation before initiation 1.
Dose Adjustments for Special Populations
Renal Impairment
Unlike enoxaparin, apixaban does not require routine dose adjustment for renal impairment in VTE treatment 1. However:
- CrCl 25-30 mL/min: Standard dosing (10 mg twice daily for 7 days, then 5 mg twice daily) appears safe based on pharmacokinetic data showing acceptable drug exposure 3
- CrCl <25 mL/min or dialysis: Apixaban 2.5 mg twice daily achieves therapeutic levels comparable to 5 mg twice daily in patients with normal renal function 4
- Avoid 5 mg twice daily in dialysis patients as this leads to supratherapeutic levels 4
This contrasts with enoxaparin, which requires dose reduction to 1 mg/kg once daily when CrCl <30 mL/min 1, 5.
Dose Reduction Criteria
Consider apixaban 2.5 mg twice daily (after the initial 7-day treatment period) if the patient meets at least 2 of the following 3 criteria 2, 6:
- Age ≥80 years
- Body weight ≤60 kg
- Serum creatinine ≥1.5 mg/dL
Patients with only one of these criteria should receive the standard 5 mg twice daily dose, as they demonstrate consistent benefit and safety compared to those without these characteristics 6.
Clinical Context and Evidence Quality
The AMPLIFY trial demonstrated apixaban's noninferiority to enoxaparin/warfarin for VTE treatment, with superior bleeding outcomes (0.6% vs 1.8% major bleeding, P<0.001) 1. However, only 2.7% of enrolled patients had cancer 1.
Important Caveats
Cancer patients with gastric or gastroesophageal lesions: LMWH (enoxaparin or dalteparin) is preferred over DOACs due to increased hemorrhage risk 1. If a DOAC must be used, apixaban may be safer than edoxaban or rivaroxaban in this population 1.
Avoid switching back and forth: Once transitioned to apixaban, do not switch back to enoxaparin or to UFH, as this increases bleeding risk 1.
Drug interactions: Apixaban is metabolized via CYP3A4 and is a P-glycoprotein substrate 1. Strong inducers or inhibitors of these pathways require careful consideration and potential dose adjustment 1.