What is the recommended dose and treatment duration of Lovenox (enoxaparin) for the prevention of Deep Vein Thrombosis (DVT) and Pulmonary Embolism (PE)?

Lovenox (Enoxaparin) Dosing for DVT/PE Prevention and Treatment

Prophylactic Dosing

For DVT prophylaxis in hospitalized medical and surgical patients, administer enoxaparin 40 mg subcutaneously once daily, starting 2 hours preoperatively for surgical patients or upon admission for medical patients, and continue until hospital discharge or full ambulation. 1

Standard Prophylaxis Regimen

• 40 mg subcutaneously once daily is the recommended dose for most patients requiring thromboprophylaxis 2, 1
• Duration: Continue for the length of hospital stay or until fully ambulatory for medical patients 1
• For surgical patients: Minimum 7-10 days post-procedure 1, 3
• Timing: Start 2-4 hours preoperatively or 10-12 hours preoperatively for surgical patients 1

Special Population Adjustments

Renal Impairment:

• Reduce dose to 30 mg subcutaneously once daily for creatinine clearance <30 mL/min 1, 3
• Renal clearance is reduced by 31% in moderate renal impairment and 44% in severe renal impairment 1
• Consider anti-Xa monitoring (target 0.5-1.5 IU/mL) for prolonged therapy in severe renal impairment 1

Obesity (BMI >30 kg/m²):

• Consider intermediate doses: 40 mg subcutaneously every 12 hours or weight-based dosing at 0.5 mg/kg subcutaneously every 12 hours 1

Pregnancy with Class III Obesity:

• Use intermediate doses of 0.5 mg/kg subcutaneously every 12 hours 1

---

Therapeutic Dosing for Acute DVT/PE Treatment

For treatment of established DVT or PE, use enoxaparin 1 mg/kg subcutaneously every 12 hours or 1.5 mg/kg subcutaneously once daily, overlapping with warfarin for minimum 5 days until INR exceeds 2.0 for at least 24 hours. 2, 1

Standard Treatment Regimens

• 1 mg/kg subcutaneously every 12 hours (preferred for large PE) 2, 1
• 1.5 mg/kg subcutaneously once daily (acceptable alternative, particularly for outpatient DVT treatment) 2, 4
• Both regimens demonstrate equivalent efficacy and safety 4

Dosing by Body Weight

Standard Weight (BMI <40 kg/m²):

• 1 mg/kg every 12 hours or 1.5 mg/kg once daily 1

Obesity (BMI ≥40 kg/m²):

• Reduce to 0.8 mg/kg subcutaneously every 12 hours 1

Severe Renal Insufficiency (CrCl <30 mL/min):

• Dose adjustment required; avoid standard dosing 2, 1
• Consider alternative anticoagulation or anti-Xa monitoring 1

Treatment Duration

• Initial phase: 5-10 days minimum 2, 1
• Standard DVT: Minimum 3-6 months 2
• PE: 6-12 months 2
• Cancer patients: Extended treatment for at least 3-6 months, with LMWH monotherapy preferred over warfarin 2, 1
• Consider dose reduction after first month in cancer patients on long-term therapy 1

---

Monitoring Recommendations

Baseline Testing

• CBC, renal and hepatic function panel, aPTT, PT/INR 1

Ongoing Monitoring

• Platelet count every 2-3 days from day 4 to day 14 for patients at risk of heparin-induced thrombocytopenia (HIT) 2
• Hemoglobin, hematocrit, and platelet count at least every 2-3 days for first 14 days, then every 2 weeks 1
• Anti-Xa monitoring is NOT routinely required for standard prophylactic or therapeutic dosing 1

When to Monitor Anti-Xa Levels

• Severe renal impairment on prolonged therapy 1
• Pregnant patients on therapeutic doses 1
• Measure 4-6 hours after dosing, after 3-4 doses 1
• Target peak anti-Xa levels:
  • Once-daily therapeutic: 1.0-1.5 IU/mL 1
  • Twice-daily therapeutic: 0.6-1.0 IU/mL 1
  • Prophylactic monitoring (if needed): 0.5-1.5 IU/mL 1

---

Critical Safety Considerations

Neuraxial Anesthesia Timing

• Avoid administration within 10-12 hours before spinal/epidural procedures 1
• For prophylactic doses after neuraxial anesthesia, may start as early as 4 hours after catheter removal but not earlier than 12 hours after the block 1
• Failure to properly time administration increases risk of spinal hematoma 1

Bleeding Risk Management

• Enoxaparin carries 2-3 fold increased bleeding risk when standard doses are used in renal insufficiency 3
• Avoid concomitant NSAIDs and antiplatelet drugs unless specifically indicated 2
• Do not switch between enoxaparin and unfractionated heparin due to increased bleeding risk 1

Advantages Over Unfractionated Heparin

• Better bioavailability and longer half-life 1
• More predictable anticoagulation effect 1, 3
• Significantly lower risk of HIT (platelet monitoring not required for most patients) 2, 1
• Once-daily dosing improves compliance and reduces healthcare costs 1

---

Common Pitfalls to Avoid

1. Not adjusting dose in renal impairment leads to drug accumulation and increased bleeding risk 1, 3
2. Using standard fixed dosing in obese patients may result in inadequate prophylaxis 1
3. Improper timing with neuraxial procedures significantly increases spinal hematoma risk 1
4. Failure to overlap with warfarin for minimum 5 days or until INR therapeutic for 24 hours 2
5. Not monitoring elderly patients with fluctuating renal function 3