Low-molecular-weight heparin (LMWH)
Brand names: Clexane, Lovenox, Enoxalem
Updated · Methodology
First line
In acute deep vein thrombosis and pulmonary embolism, LMWHs are first-line initial anticoagulation with transition to oral anticoagulants (DOACs or warfarin) after 5–10 days. Dose 1 mg/kg subcutaneously twice daily or 1.5 mg/kg once daily. In cancer-associated venous thromboembolism, enoxaparin remains the preferred long-term option for the first 6 months per ASCO 2023.
Sources
ICD-10: I82 · ICD-11: BD71
First line
First-line for venous thromboembolism prophylaxis after major surgery and in hospitalized acutely ill medical patients per ACCP 2021 and 2024. Standard dose: 40 mg subcutaneously once daily in general surgery; 30 mg twice daily or 40 mg once daily in orthopedic surgery. Duration: 7–10 days in general surgery, up to 35 days after major orthopedic procedures (hip and knee replacement, hip fracture).
Sources
ICD-10: Z79.0
The drug is promoted for these uses outside international guidelines. Each entry below is analyzed against AEMPS, FDA, EMA, Cochrane and major RCTs.
Not recommended
Enoxaparin is a low-molecular-weight heparin. It is used for prevention and treatment of venous thromboembolism, for acute coronary syndrome, and during surgery with high thrombotic risk (ACCP 2024, 2023). In anti-aging regimens, enoxaparin is used for blood thinning in people without confirmed thrombotic risk. In healthy adults, no clinical studies of prophylactic use exist. The drug raises the risk of major bleeding and heparin-induced thrombocytopenia (HIT, which can cause paradoxical thrombosis) and requires subcutaneous injection. If enoxaparin was prescribed for blood thinning in a healthy person, consider seeking a second opinion.
A low-molecular-weight heparin with mean mass 4500 Da. Potentiates antithrombin III and inactivates factor Xa and, to a lesser extent, thrombin (factor IIa); anti-Xa/anti-IIa ratio is about 3.8:1. Predictable action without routine coagulation monitoring. Subcutaneous bioavailability 92%; half-life 4–5 hours. Renal elimination – adjust dose in severe renal impairment.
Boxed warning
FDA boxed warning: epidural or spinal hematomas with paralysis risk in patients receiving LMWH around neuraxial anesthesia or spinal puncture. Respect dosing intervals between LMWH and the procedure.
AEMPS summary of product characteristics (section 4.6): in humans there is no evidence that enoxaparin crosses the placenta in the second and third trimesters, and there are no data for the first trimester. Animal studies showed no fetotoxicity or teratogenicity, and placental transfer was minimal. Enoxaparin is used in pregnancy only if the physician has established a clear need; pregnant women on enoxaparin are monitored closely for bleeding or excessive anticoagulation and warned about the risk of haemorrhage. Overall, the data show no increase in the risk of haemorrhage, thrombocytopenia or osteoporosis compared with non-pregnant women, other than that seen in pregnant women with prosthetic heart valves. If epidural anaesthesia is planned, enoxaparin is stopped beforehand.
Compatible with breastfeeding. Enoxaparin essentially does not pass into milk and is not absorbed from the infant GI tract.
Reference information, not a clinical decision. Discuss feeding pauses or changes with your physician or an IBCLC.
1 pair found. Sorted from critical to minor.
Mechanism
Enoxaparin blocks factor Xa and ticagrelor blocks platelet aggregation, so two separate points of haemostasis are hit at once. The enoxaparin label asks for medical supervision and laboratory monitoring when it is combined with antiplatelets, anti-inflammatory doses of salicylates and NSAIDs, and it also names thrombolytics and other anticoagulants.
Symptoms
Extensive bruising at injection sites, gum and nose bleeding, black stools, pink urine, unexplained back or abdominal pain that may indicate internal bleeding. Progressive anaemia shows as fatigue and pallor.
Management
The combination exists in hospital protocols for acute coronary syndrome, with defined doses, duration and monitoring. Outside that setting they are not stacked on personal initiative, still less with an NSAID on top. Monitor haemoglobin, platelets and renal function, since enoxaparin accumulates when filtration falls.
Sources
Verbatim lines from the interaction sections, in the language of the label
«- Salicilatos sistémicos, ácido acetilsalicílico a dosis antiinflamatorias y AINEs, incluyendo ketorolaco;»AEMPS, section 4.5 · Open on CIMA
«DRUG INTERACTIONS: Whenever possible, agents which may enhance the risk of hemorrhage should be discontinued prior to initiation of Lovenox therapy. These agents include medications such as…»FDA, section 7 · Open on DailyMed
«- Salicilatos sistémicos, ácido acetilsalicílico a dosis antiinflamatorias y AINEs, incluyendo ketorolaco;»AEMPS, section 4.5 · Open on CIMA
«- Salicilatos sistémicos, ácido acetilsalicílico a dosis antiinflamatorias y AINEs, incluyendo ketorolaco;»AEMPS, section 4.5 · Open on CIMA
«DRUG INTERACTIONS: Whenever possible, agents which may enhance the risk of hemorrhage should be discontinued prior to initiation of Lovenox therapy. These agents include medications such as…»FDA, section 7 · Open on DailyMed
«DRUG INTERACTIONS: Whenever possible, agents which may enhance the risk of hemorrhage should be discontinued prior to initiation of Lovenox therapy. These agents include medications such as…»FDA, section 7 · Open on DailyMed
«- Inhibidores de la agregación plaquetaria, incluyendo ácido acetilsalicílico a dosis antiagregantes (cardioprotección), clopidogrel, ticlopidina, antagonistas de la glucoproteína IIb/AEMPS, section 4.5 · Open on CIMA
«- Inhibidores de la agregación plaquetaria, incluyendo ácido acetilsalicílico a dosis antiagregantes (cardioprotección), clopidogrel, ticlopidina, antagonistas de la glucoproteína IIb/AEMPS, section 4.5 · Open on CIMA
«- Glucocorticoides sistémicos.»AEMPS, section 4.5 · Open on CIMA
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Enoxaparin sodium is evaluated for the following indications with varying evidence strength: Venous thromboembolism prophylaxis (evidence tier A), Venous thromboembolism (evidence tier A), Anti-aging and longevity (evidence tier F). See the full indication matrix with dosing and citations above on this page.
Common side effects of Enoxaparin sodium (≥ 1 in 100): Injection site hematoma and pain, Minor bleeding, Transient thrombocytopenia, Elevated liver enzymes. See the Safety section for uncommon and serious reactions.
AEMPS summary of product characteristics (section 4.6): in humans there is no evidence that enoxaparin crosses the placenta in the second and third trimesters, and there are no data for the first trimester. Animal studies showed no fetotoxicity or teratogenicity, and placental transfer was minimal. Enoxaparin is used in pregnancy only if the physician has established a clear need; pregnant women on enoxaparin are monitored closely for bleeding or excessive anticoagulation and warned about the risk of haemorrhage. Overall, the data show no increase in the risk of haemorrhage, thrombocytopenia or osteoporosis compared with non-pregnant women, other than that seen in pregnant women with prosthetic heart valves. If epidural anaesthesia is planned, enoxaparin is stopped beforehand.
Compatible with breastfeeding. Enoxaparin essentially does not pass into milk and is not absorbed from the infant GI tract.
Enoxaparin sodium is contraindicated in: Enoxaparin or heparin hypersensitivity; Active clinically significant bleeding; History of heparin-induced thrombocytopenia; Platelet count under 50×10⁹/L; Severe uncontrolled hypertension. Full list in the Safety section.
FDA boxed warning: epidural or spinal hematomas with paralysis risk in patients receiving LMWH around neuraxial anesthesia or spinal puncture. Respect dosing intervals between LMWH and the procedure.
Direct links to regulator labels. Open in a new tab.
Acetylsalicylic acid, Apixaban, Clopidogrel, Dabigatran, Nattokinase (serine protease from fermented soybean natto, Bacillus subtilis var. natto), Rivaroxaban, Ticagrelor, Warfarin