LOVENOX
Clinical safety rating
cautionComprehensive 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. |
| Molecular Weight | 4500 |
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 | Use only if clearly needed; no teratogenic effects reported in animal studies, limited human data. |
| 2nd trimester | Use only if clearly needed; known risk of maternal hemorrhage, preterm labor if used near delivery. |
| 3rd trimester | Use with caution; increased risk of bleeding, especially during delivery. Consider timing of discontinuation. |
Clinical note
Comprehensive clinical and safety monograph for LOVENOX (LOVENOX).
| Placental transfer | Enoxaparin does not cross the placenta due to high molecular weight; no evidence of placental transfer. |
| Breastfeeding | Excreted in breast milk in minimal amounts; unlikely to cause adverse effects in infants. Monitor for bleeding in infant if high maternal doses. |
| Lactation Rating | L2 (Probably Compatible) |
| 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 | 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. |
■ 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 bleedingHistory of heparin-induced thrombocytopeniaHypersensitivity to enoxaparin or heparinThrombocytopenia (platelet count <100,000/mm³)
| 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 |
| Food/Dietary | No specific food restrictions; avoid excessive alcohol consumption as it may increase bleeding risk. |
| Clinical Pearls | Enoxaparin is a low molecular weight heparin (LMWH) with predictable pharmacokinetics, eliminating the need for routine monitoring of anti-Xa activity in most patients. Dosing is based on weight and renal function; adjust for CrCl <30 mL/min (e.g., 30 mg once daily for VTE prophylaxis). Protamine sulfate partially reverses anticoagulant effect (60% neutralization). Avoid in patients with history of heparin-induced thrombocytopenia (HIT); check platelet counts every 2-3 days during therapy. Subcutaneous injection technique: administer in lateral abdominal wall, pinch skin, insert needle at 45-90° angle, do not rub site. Spinal/epidural hematoma risk with neuraxial anesthesia — remove indwelling catheter at least 12 hours after last prophylactic dose (24 hours for treatment doses). |
| Patient Advice | Inject enoxaparin exactly as prescribed; do not skip doses. · Rotate injection sites (left/right side of abdomen) to reduce bruising. · Do not massage the injection site after administration. · Watch for signs of bleeding: unusual bruising, black/tarry stools, pink/red urine, coughing up blood, or severe headache. · Seek emergency care for sudden back pain, numbness, or leg weakness (possible spinal hematoma). · Tell all healthcare providers you are taking this blood thinner before procedures or surgeries. · Use soft toothbrush and electric razor to minimize bleeding risk. · Avoid aspirin, NSAIDs, and other blood thinners unless prescribed by your doctor. |
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