What is Lovenox (enoxaparin)?

Lovenox (Enoxaparin)

Lovenox (enoxaparin) is a low-molecular-weight heparin (LMWH) with greater activity against Factor Xa than thrombin, providing more predictable anticoagulation than unfractionated heparin with reduced risk of heparin-induced thrombocytopenia. 1

Mechanism of Action

• Binds to and potentiates the action of antithrombin
• Inhibits coagulation factors XIa, IXa, Xa, and IIa (thrombin)
• Has an ex vivo 4:1 ratio of Factor Xa to thrombin activity 1
• Prevents formation of blood clots through this inhibitory action 2

Pharmacological Advantages Over Unfractionated Heparin

• Reduced binding to plasma proteins resulting in more predictable anticoagulant effect
• Longer half-life (requires less frequent dosing)
• Higher bioavailability when administered subcutaneously
• Linear dose-response relationship
• Reduced risk of heparin-induced thrombocytopenia 1
• No requirement for routine laboratory monitoring 3

Clinical Applications

Enoxaparin is FDA-approved for:

• Prevention of venous thromboembolism (VTE) in surgical and medical patients
• Treatment of acute deep vein thrombosis (DVT) with or without pulmonary embolism (PE)
• Treatment of ST-segment elevation myocardial infarction (STEMI) 2
• Extended treatment of symptomatic VTE in cancer patients 1

Standard Dosing Regimens

VTE Prophylaxis:

• Standard prophylaxis: 40 mg subcutaneously once daily 4
• High-risk surgical patients: 30 mg subcutaneously twice daily 4

VTE Treatment:

• 1.0 mg/kg subcutaneously every 12 hours (preferred for higher thrombotic risk) 1
• 1.5 mg/kg subcutaneously once daily (preferred for higher bleeding risk) 1, 4

Special Populations:

• Renal impairment (CrCl <30 mL/min):
  • Prophylactic: 30 mg subcutaneously once daily
  • Therapeutic: 1 mg/kg subcutaneously once daily 4
• Elderly patients (≥75 years) with STEMI: No initial bolus, reduced dose of 0.75 mg/kg every 12 hours 2

Safety Considerations

Contraindications:

• Active major bleeding at any site, tissue, or organ
• Thrombocytopenia with positive in vitro test for antiplatelet antibody
• Known sensitivity to enoxaparin, heparin, sulfites, benzyl alcohol, or pork products
• Severe renal impairment (requires dose adjustment) 1

Monitoring:

• Unlike unfractionated heparin, routine laboratory monitoring is not required
• Platelet count monitoring is not indicated for most patients due to lower risk of HIT 1
• Consider monitoring anti-Xa levels in patients with severe renal impairment, obesity, or pregnancy 1

Comparative Efficacy

• Enoxaparin has demonstrated superior efficacy compared to unfractionated heparin in:

  • Acute coronary syndromes (ESSENCE trial showed reduction in death, MI, or recurrent angina) 1
  • STEMI with fibrinolytic therapy (ExTRACT-TIMI 25 trial showed reduced mortality and recurrent MI) 2
  • Cancer, orthopedic, and vascular surgery patients 3

• For DVT/PE treatment, efficacy is similar to unfractionated heparin but with the advantage of outpatient administration 3

Practical Advantages

• Can be administered at home without laboratory monitoring
• Fixed or weight-based dosing
• Once or twice daily administration
• Cost-effective compared to unfractionated heparin in many clinical scenarios 3

Enoxaparin represents an important advance in anticoagulation therapy with improved efficacy, safety, and convenience compared to traditional unfractionated heparin in multiple clinical settings.