Overview
Enoxaparin is a low molecular weight heparin anticoagulant used for prevention and treatment of thromboembolic disorders. It works by enhancing antithrombin III activity to inhibit Factor Xa and thrombin, with a higher anti-Factor Xa to anti-Factor IIa ratio than unfractionated heparin. It is administered subcutaneously and requires monitoring for bleeding risks.
Mechanism of Action
Enoxaparin enhances antithrombin III activity, primarily inhibiting Factor Xa with some anti-Factor IIa (thrombin) activity. It has a higher anti-Factor Xa to anti-Factor IIa ratio (approximately 14:1) compared to unfractionated heparin (approximately 1.2:1), resulting in more predictable anticoagulant effects with less effect on aPTT.
Indications
- Prophylaxis of deep vein thrombosis (DVT) following hip or knee replacement surgery
- Prophylaxis of DVT in abdominal surgery patients at risk
- Treatment of acute DVT with or without pulmonary embolism
- Prevention of ischemic complications in unstable angina and non-Q-wave myocardial infarction
- Prophylaxis of DVT in medical patients during acute illness
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
Dosing varies by indication, typically administered subcutaneously. Common regimens include 30 mg twice daily or 40 mg once daily for prophylaxis, and 1 mg/kg every 12 hours for treatment of DVT/PE. Dose adjustments required for renal impairment and in obese patients.
Contraindications
- Active major bleeding
- History of immune-mediated heparin-induced thrombocytopenia (HIT) within past 100 days or presence of circulating antibodies
- Known hypersensitivity to enoxaparin sodium
- Known hypersensitivity to heparin or pork products
- Known hypersensitivity to benzyl alcohol (in multiple-dose formulation only)
Side Effects
- Bleeding complications
- Thrombocytopenia
- Injection site reactions
- Elevated liver enzymes
- Allergic reactions including anaphylaxis
- Hematoma at injection site
- Fever
- Nausea
Interactions
- Anticoagulants (warfarin, other heparins)
- Anti-platelet agents (aspirin, clopidogrel)
- NSAIDs including ketorolac
- Thrombolytics
- Other medications affecting hemostasis
- Close monitoring required if coadministration essential
Counseling Points
- Administer by subcutaneous injection only
- Rotate injection sites to prevent bruising
- Monitor for signs of bleeding or unusual bruising
- Do not massage injection site
- Inform all healthcare providers of enoxaparin use
- Carry identification indicating anticoagulant therapy
- Report any signs of allergic reaction immediately