LOVENOX
Clinical safety rating: caution
Comprehensive clinical and safety monograph for LOVENOX (LOVENOX).
Low molecular weight heparin (LMWH) that binds to antithrombin III, enhancing its inhibition of factor Xa and thrombin, thereby preventing thrombus formation.
| Metabolism | Primarily metabolized in the liver by desulfation and depolymerization to lower molecular weight fragments with reduced anticoagulant activity. |
| Excretion | Renal: 40-60% as active and inactive fragments via glomerular filtration and tubular secretion; biliary/fecal: minimal, <10%. |
| Half-life | Terminal half-life: 4.5-7 hours after subcutaneous administration; prolonged in renal impairment (up to 16 hours with CrCl <30 mL/min), requiring dose adjustment. |
| Protein binding | Antithrombin III (ATIII) binding: ~100% (enoxaparin is an ATIII-dependent inhibitor); nonspecific protein binding: negligible (<1%). |
| Volume of Distribution | Vd: 0.1-0.2 L/kg; confined mainly to intravascular space, with limited extravascular distribution; reflects low tissue penetration. |
| Bioavailability | Subcutaneous: 92-100% (nearly complete). |
| Onset of Action | Subcutaneous: 3-5 hours; intravenous: immediate, within minutes. |
| Duration of Action | Subcutaneous: 12-24 hours (anti-Factor Xa activity persists up to 24 hours; clinical effect may last 12 hours); intravenous: shorter duration, typically 6-8 hours for clinical effect. |
1 mg/kg subcutaneously every 12 hours or 1.5 mg/kg subcutaneously once daily for treatment of venous thromboembolism; 40 mg subcutaneously once daily for prophylaxis in abdominal surgery, hip or knee replacement; 30 mg subcutaneously every 12 hours for prophylaxis in medical patients; 0.5 mg/kg subcutaneously once daily for prophylaxis in patients with acute coronary syndrome.
| Dosage form | INJECTABLE |
| Renal impairment | For CrCl <30 mL/min: treatment dose 1 mg/kg subcutaneously once daily; prophylaxis dose 30 mg subcutaneously once daily. No adjustment for CrCl 30-50 mL/min but monitor closely. |
| Liver impairment | No specific dosing adjustment recommended for hepatic impairment based on Child-Pugh score; use with caution in severe hepatic impairment due to increased risk of bleeding. |
| Pediatric use | Prophylaxis: 0.5 mg/kg subcutaneously every 12 hours. Treatment: 1 mg/kg subcutaneously every 12 hours. Maximum single dose 120 mg. Weight must be >5 kg. |
| Geriatric use | Elderly patients >75 years old: increased risk of bleeding; consider lower doses (e.g., 0.75 mg/kg every 12 hours for treatment) and monitor renal function closely; no specific dose adjustment solely by age but use with caution. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for LOVENOX (LOVENOX).
| Breastfeeding | Excreted in human milk in negligible amounts; M/P ratio not established. Considered compatible with breastfeeding; monitor infant for signs of bruising or bleeding. |
| Teratogenic Risk | FDA Pregnancy Category B. No evidence of teratogenicity in animal studies. First trimester: No known increased risk of major malformations. Second/Third trimesters: Risk of maternal hemorrhage, placental abruption, and fetal hemorrhage due to anticoagulant effect. Use only if clearly needed. |
| Fetal Monitoring |
■ FDA Black Box Warning
Spinal/epidural hematomas may occur in patients anticoagulated with LMWH or heparinoids who receive neuraxial anesthesia or undergo spinal puncture. These hematomas can result in long-term or permanent paralysis.
| Serious Effects |
["Active major bleeding","History of heparin-induced thrombocytopenia (HIT)","Hypersensitivity to enoxaparin, heparin, or pork products","Use of indwelling epidural catheter for analgesia or therapy"]
| Precautions | ["Risk of bleeding, especially with invasive procedures or concomitant use of antiplatelet agents","Heparin-induced thrombocytopenia (HIT) and heparin-induced thrombocytopenia with thrombosis (HITTS)","Increased risk of spinal/epidural hematoma with neuraxial anesthesia","Use with caution in patients with renal impairment (creatinine clearance <30 mL/min) due to reduced clearance","Monitor for signs of bleeding and thrombocytopenia"] |
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| Monitor maternal CBC (platelets), anti-Xa levels (if prolonged use or high-risk), signs of bleeding or thrombosis. Fetal monitoring: ultrasound for growth and placental evaluation if bleeding occurs. |
| Fertility Effects | No known adverse effects on fertility in animal studies. Limited human data; unlikely to impair fertility at therapeutic doses. |