Overview
Enoxaparin sodium is a low molecular weight heparin anticoagulant used to prevent and treat thrombotic conditions. It works by inhibiting Factor Xa and Factor IIa (thrombin) in the coagulation cascade, with a higher anti-Factor Xa to anti-Factor IIa activity ratio compared to unfractionated heparin. It is administered subcutaneously and requires monitoring for bleeding risks.
Mechanism of Action
Enoxaparin sodium is a low molecular weight heparin that binds to antithrombin III, enhancing its inhibition of Factor Xa and Factor IIa (thrombin) in the coagulation cascade. It has a higher ratio of anti-Factor Xa to anti-Factor IIa activity (approximately 14:1) compared to unfractionated heparin (approximately 1.2:1), providing more predictable anticoagulant effects with less effect on global clotting tests like aPTT.
Indications
- Prophylaxis of deep vein thrombosis (DVT) in patients undergoing hip or knee replacement surgery
- Prophylaxis of DVT in medical patients at risk due to severely restricted mobility during acute illness
- Treatment of acute DVT with or without pulmonary embolism
- Prophylaxis of ischemic complications in unstable angina and non-Q-wave myocardial infarction
- Treatment of acute ST-segment elevation myocardial infarction (STEMI) managed medically or with percutaneous coronary intervention
Common Doses
- 30 mg/0.3 mL
- 40 mg/0.4 mL
- 60 mg/0.6 mL
- 80 mg/0.8 mL
- 100 mg/1 mL
- 120 mg/0.8 mL
- 150 mg/1 mL
Dosage
Dosage varies by indication, typically administered subcutaneously. Common regimens include 40 mg once daily for DVT prophylaxis, 1 mg/kg every 12 hours or 1.5 mg/kg once daily for DVT treatment, and weight-based dosing for acute coronary syndromes. Dose adjustments are required for renal impairment.
Contraindications
- Active major bleeding
- History of immune-mediated heparin-induced thrombocytopenia (HIT) within the past 100 days or presence of circulating antibodies
- Known hypersensitivity to enoxaparin sodium, heparin, or pork products
- Known hypersensitivity to benzyl alcohol (in multiple-dose formulation only)
Side Effects
- Bleeding complications (e.g., hematoma, epistaxis, hematuria)
- Thrombocytopenia
- Elevated liver enzymes
- Injection site reactions (pain, erythema, hematoma)
- Hypersensitivity reactions (pruritus, urticaria, anaphylaxis)
Interactions
- Increased risk of hemorrhage with anticoagulants (e.g., warfarin), antiplatelet agents (e.g., aspirin, clopidogrel), NSAIDs (e.g., ibuprofen, ketorolac), and thrombolytics
- Close monitoring required if coadministration is essential
Counseling Points
- Administer by subcutaneous injection, typically in the abdomen, avoiding the navel
- Rotate injection sites to minimize bruising
- Monitor for signs of bleeding (e.g., unusual bruising, blood in urine/stool) and report immediately
- Inform all healthcare providers of enoxaparin use before any procedures
- Do not discontinue without medical advice