Low-molecular-weight heparin (antithrombotic)
Enoxaparin is an anticoagulant (low molecular weight heparin) given by subcutaneous injection, used to prevent and treat blood clots (deep vein thrombosis and pulmonary embolism) and in acute coronary syndromes. The injections are usually given by the patient or a family member after training.
Also known as: Clexane, Lovenox, enoxaparin
Enoxaparin with aspirin increases bleeding risk.
Aspirin and enoxaparin (low-molecular-weight heparin) act on complementary haemostatic pathways — platelet antiaggregation and anti-Xa/antithrombin — and the combination is used intentionally in acute coronary syndrome. The bleeding risk (particularly digestive and at puncture sites) is additive, especially in the elderly, renal impairment, low body weight or with other antiplatelet/anticoagulant agents. Monitor signs of bleeding, renal function and platelet count (risk of heparin-induced thrombocytopenia, especially with enoxaparin), and consider gastroprotection.
Aspirin + enoxaparin: additive bleeding risk. Use only with a clear indication (ACS) and monitor bleeding, renal function and thrombocytopenia.
LMWH potentiates antithrombin and aspirin blocks thromboxane; additive bleeding risk.
Monitor injection-site bleeding, bruising and blood count.
Large haematoma, melaena, prolonged bleeding.
Use the combination only when indicated (e.g. ACS); monitor for bleeding.
DailyMed (FDA) — approved Enoxaparin label: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=5017a927-2a24-4f27-89f9-27c805bf7d59 ; approved Aspirin label: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=3ba0a9f2-062a-401e-82eb-54383a822366 — additional reference: Prontuário Terapêutico do INFARMED (11th ed., 2012)
Enoxaparin with clopidogrel increases the risk of major bleeding.
Clopidogrel (a P2Y12 inhibitor) and enoxaparin (a low molecular weight heparin) act on different haemostasis pathways and the bleeding risk is additive: the clopidogrel label states that "P2Y12 inhibitors, including clopidogrel, increase the risk of bleeding" and that the risk increases "with the concomitant use of other drugs that increase the risk of bleeding"; the enoxaparin label warns that the risk of epidural haematomas increases with "the concomitant use of other drugs that affect haemostasis, such as NSAIDs, platelet inhibitors and other anticoagulants" and recommends extreme caution with platelet inhibitors. The combination is used in specific settings (e.g. acute coronary syndromes under intervention, during a short transition period), but requires: monitoring for bleeding (including retroperitoneal and intracranial), blood count monitoring, and respecting the recommended intervals between doses around procedures (e.g. epidural catheter removal 12–24h after the enoxaparin dose).
Clopidogrel + enoxaparina: additive bleeding (antiplatelet + anticoagulant). Watch for bleeding signs; use with extreme caution.
Anticoagulant (LMWH) + antiplatelet (P2Y12), with additive bleeding.
Monitor blood count and clinical signs of bleeding.
Intracranial or GI bleeding; spontaneous bruising.
Use with caution in high bleeding-risk patients; monitor.
DailyMed (FDA) — approved Enoxaparin label: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=5017a927-2a24-4f27-89f9-27c805bf7d59 ; approved Clopidogrel label: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=55731d95-0c99-ff61-e063-6394a90a1ab5 — additional reference: Prontuário Terapêutico do INFARMED (11th ed., 2012)
Tranexamic acid combined with enoxaparin increases thrombotic risk; assess the indication carefully.
There is no documented pharmacokinetic interaction between tranexamic acid (an antifibrinolytic — it inhibits fibrin dissolution by plasmin) and enoxaparin (an anticoagulant); the problem is the combination of opposing haemostasis mechanisms: the tranexamic acid label contraindicates the drug in patients with active thromboembolic disease or an intrinsic risk of thrombosis, and the enoxaparin label warns about the bleeding risk with drugs that affect haemostasis. The combination occurs in acute bleeding situations in anticoagulated patients (e.g. trauma, major haemorrhage) where the antifibrinolytic is used for bleeding control — a clinical risk/benefit decision. During the combination, watch for bleeding and thrombosis signs (DVT, PE, vascular occlusion) and monitor the blood count; tranexamic acid should be stopped if visual symptoms or suspected retinal occlusion occur.
Tranexamic acid + enoxaparin: antifibrinolytic + anticoagulant — opposing haemostasis mechanisms. Assess risk/benefit and watch thrombosis/bleeding.
The antifibrinolytic reduces clot lysis while LMWH enhances anticoagulation; the balance is paradoxical and thrombotic risk is additive in at-risk patients.
Monitor for signs of DVT, pulmonary embolism and bleeding.
Limb pain or swelling, sudden dyspnoea, persistent bleeding.
Use only when bleeding outweighs thrombotic risk; monitor for signs of thrombosis.
DailyMed (FDA) — approved Tranexamic acid label: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=4877eacd-fda7-4708-93a5-81052c1d2e14 ; approved Enoxaparin label: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=5017a927-2a24-4f27-89f9-27c805bf7d59 — additional reference: Prontuário Terapêutico do INFARMED (11th ed., 2012)
Alcohol increases the bleeding risk in patients treated with enoxaparin.
Limit alcohol intake during treatment.
EMC-UK (MHRA) — approved Enoxaparin SmPC: https://www.medicines.org.uk/emc/product/9329/smpc
Enoxaparin elimination is renal; at CrCl < 30 ml/min the risk of accumulation and bleeding is high.
At CrCl < 30 ml/min, use with extreme caution or an alternative; adjust the dose per the SmPC.
EMC-UK (MHRA) — approved Enoxaparin SmPC: https://www.medicines.org.uk/emc/product/9329/smpc
Enoxaparin is contraindicated in HIT (current or previous) because of the risk of antibody-mediated thrombosis.
Do not use enoxaparin (or other LMWH/heparins) in HIT; consider an alternative anticoagulant.
EMC-UK (MHRA) — approved Enoxaparin SmPC: https://www.medicines.org.uk/emc/product/9329/smpc
Enoxaparin is the anticoagulant of choice in pregnancy when indicated; use under medical supervision.
Can be used in the trimesters in which anticoagulation is needed, with monitoring (anti-Xa if indicated).
Enoxaparin is not excreted in significant amounts into breast milk; compatible with breastfeeding.
No specific additional contraception; the anticoagulant indication dominates.
EMC-UK (MHRA) — approved Enoxaparin SmPC: https://www.medicines.org.uk/emc/product/9329/smpc
Clinical and educational support tool. The information does not replace a medical prescription or the opinion of a qualified healthcare professional.
Low molecular weight heparin (LMWH) that potentiates antithrombin III, inhibiting preferentially factor Xa (anti-Xa activity) and, to a lesser extent, factor IIa (thrombin). Peak anti-Xa and anti-IIa activities occur 3–5 hours after subcutaneous injection; the anti-Xa/anti-IIa ratio is ~3.6:1.
Enoxaparin binds to antithrombin III, accelerating the inactivation of factor Xa (main effect) and of thrombin (factor IIa). Preferential factor Xa inhibition, with less plasma protein binding than unfractionated heparin, confers more predictable pharmacokinetics and a lower risk of thrombocytopenia.
Absolute bioavailability after subcutaneous injection (1.5 mg/kg) is approximately 100%. Peak anti-Xa activity occurs 3–5 hours after injection; steady state is reached on day 2 (40 mg/day and 1.5 mg/kg/day regimens) or day 4 (1 mg/kg twice daily). The volume of distribution of anti-Xa activity is ~4.3 L.
Enoxaparin is metabolised primarily in the liver by desulfation and/or depolymerisation to lower molecular weight species with much reduced biological potency. Renal clearance of active fragments represents ~10% of the dose; total renal excretion (active and inactive) is ~40% of the dose.
Elimination half-life based on anti-Xa activity is ~4.5 hours after a single subcutaneous dose, increasing to ~7 hours after repeated dosing. Significant anti-Xa activity persists in plasma for ~12 hours after a 40 mg once-daily dose.
Medicines from the same therapeutic group (ATC classification) or the same pharmacological class.
