What is the duration of treatment with enoxaparin (Low Molecular Weight Heparin) and apixaban (Factor Xa inhibitor) for Deep Vein Thrombosis (DVT)?

Duration of Enoxaparin and Apixaban for DVT Treatment

For uncomplicated DVT, you do not need enoxaparin at all—start apixaban 10 mg orally twice daily for 7 days, then transition to 5 mg twice daily for at least 3 months, with extended therapy considered based on risk factors. 1

Standard Treatment Regimen

Apixaban Monotherapy (Preferred Approach)

• Apixaban can be initiated directly without any parenteral anticoagulation for DVT treatment 1
• Initial phase: 10 mg orally twice daily for the first 7 days 1
• Maintenance phase: 5 mg orally twice daily starting on day 8 1
• Minimum duration: 3 months for provoked DVT 1
• Extended therapy: After 6 months of initial therapy, either continue 5 mg twice daily or reduce to 2.5 mg twice daily for secondary prevention 1

When Enoxaparin Is Actually Needed

Enoxaparin is only required in specific circumstances:

• Cancer-associated DVT: Enoxaparin 1 mg/kg subcutaneously every 12 hours or 1.5 mg/kg once daily is preferred for the first 6 months 1
• Severe renal impairment (CrCl <30 mL/min): Use enoxaparin instead of apixaban 1
• Inability to take oral medications: Enoxaparin 1 mg/kg every 12 hours or 1.5 mg/kg once daily until oral therapy is feasible 1

Duration of Anticoagulation

Minimum Treatment Duration

• All DVT patients: At least 3 months of anticoagulation 1
• Provoked DVT (surgery, trauma, temporary risk factor): 3 months is typically sufficient 1

Extended Anticoagulation Indications

• Unprovoked DVT: Consider indefinite anticoagulation with annual reassessment 1, 2
• Recurrent VTE: Indefinite anticoagulation recommended 1
• Active cancer: Continue anticoagulation for at least 6 months, often indefinitely while cancer is active 1
• Persistent risk factors: Continue anticoagulation as long as risk factors remain 2

Dose Reduction for Extended Therapy

• After 6 months of standard-dose apixaban (5 mg twice daily): Can reduce to 2.5 mg twice daily for extended secondary prevention 1
• This reduced dose maintains efficacy while potentially lowering bleeding risk 1

Special Populations

Cancer Patients

• LMWH (enoxaparin or dalteparin) is preferred over apixaban for the first 6 months 1
• Enoxaparin: 1 mg/kg every 12 hours (long-term dosing at this level not extensively tested in cancer) 1
• Dalteparin: 200 units/kg daily for 1 month, then 150 units/kg daily for months 2-6 (Category 1 evidence) 1

Renal Impairment

• CrCl 15-30 mL/min: Apixaban can be used with caution at standard initial dosing (10 mg twice daily × 7 days, then 5 mg twice daily), but consider 2.5 mg twice daily for extended therapy 2
• CrCl <15 mL/min: Apixaban is contraindicated; use enoxaparin with anti-Xa monitoring or unfractionated heparin 1, 2

Common Pitfalls to Avoid

• Do not unnecessarily bridge with enoxaparin before starting apixaban—apixaban has a built-in loading dose regimen that eliminates this need for most patients 1
• Do not use enoxaparin 1.5 mg/kg once daily for long-term cancer-associated DVT treatment—this dosing has not been adequately studied for extended therapy in cancer patients 1
• Do not stop anticoagulation at 3 months without assessing for unprovoked DVT or persistent risk factors—these patients benefit from extended therapy 1, 2
• Monitor renal function periodically in patients with borderline renal impairment—deterioration below CrCl 15 mL/min contraindicates apixaban 2