Enoxaparin

Pronunciation: ee-nox-a-PAIR-in.

Generic name
enoxaparin sodium
Drug class
Anticoagulant (low molecular weight heparin, LMWH)
Form
Solution for injection, pre-filled syringe or multi-dose vial (20 mg-150 mg depending on market, strength, and indication)
Route
Subcutaneous injection (some hospital indications use intravenous administration)
Legal status
Prescription-only, hospital/specialist-administered injectable

Availability and supply rules vary by country

Trade names by country: United States · United Kingdom · Canada · Australia · New Zealand

Australia: Clexane / Clexane Forte (5) · Full directory

What enoxaparin sodium is and how it works

Enoxaparin is an injectable anticoagulant (blood thinner) called a low molecular weight heparin (LMWH). It is used to prevent and treat blood clots in the veins (venous thromboembolism), including after certain types of surgery or during periods of restricted mobility, and as part of treatment for certain heart attacks and unstable angina. (1)

Enoxaparin carries a genuine, serious risk of major bleeding, and a specific boxed-warning risk of a spinal or epidural blood clot if it is given around the time of spinal or epidural anesthesia or a spinal puncture, which can cause long-term or permanent paralysis. It also carries a risk of a drop in platelet count, including a rarer but serious form (heparin-induced thrombocytopenia with thrombosis), and its dose depends on your body weight, kidney function, and the reason you are taking it. It should only ever be given and monitored by a healthcare professional -- never adjust the dose or timing yourself.

Mechanism of action: how enoxaparin sodium works

Enoxaparin is a low molecular weight heparin produced by controlled depolymerisation of heparin, which potentiates antithrombin's inhibition of factor Xa and, to a lesser extent, thrombin (factor IIa), interrupting the coagulation cascade. (1)

What enoxaparin sodium is used for

Prevention of blood clots after surgery or during restricted mobility

Used to prevent deep vein thrombosis (DVT) in adults having abdominal surgery, hip replacement surgery, or knee replacement surgery, and in medical patients whose mobility is severely restricted during an acute illness. (1)

Treatment of deep vein thrombosis and pulmonary embolism

Used to treat an acute deep vein thrombosis or pulmonary embolism (a blood clot in the lungs) in adults, as an inpatient or, in some cases, as an outpatient. (1)

Certain heart attacks and unstable angina (acute coronary syndrome)

Used to prevent complications of unstable angina and certain heart attacks (non-Q-wave myocardial infarction), and to treat acute ST-segment elevation myocardial infarction (STEMI) in people managed medically or with a coronary procedure (PCI). (1)

Extended treatment of cancer-associated blood clots and dialysis circuit anticoagulation

In the UK, also used for extended treatment of blood clots associated with cancer, and to help prevent clotting in the tubing (extracorporeal circuit) during hemodialysis. (2)

Before taking enoxaparin sodium

Do not take / not appropriate for

  • Do not use enoxaparin if you have active, clinically significant bleeding. (all countries) (1) (2)
  • Do not use enoxaparin if you have thrombocytopenia (a low platelet count) together with a positive blood test for antibodies against platelets in the presence of enoxaparin, or a history of heparin-induced thrombocytopenia within the past 100 days. (all countries) (1) (2)
  • Do not use enoxaparin if you have a known allergy to enoxaparin, heparin, other low molecular weight heparins, or (for some formulations) pork products or benzyl alcohol. (all countries) (1) (4)
  • In the UK, spinal or epidural anesthesia must not be performed within 24 hours of a therapeutic (treatment-level) dose of enoxaparin. (United Kingdom) (2)

Tell your clinician about

  • Any history of bleeding problems, stomach ulcers, endocarditis, or recent surgery, especially recent brain, spine, or eye surgery.
  • Your kidney function and body weight, since dosing and safety depend heavily on both, particularly in severe kidney impairment.
  • Any planned spinal or epidural anesthesia, spinal puncture (such as a lumbar puncture), or spinal catheter, and any history of spine problems or spinal surgery.
  • All other medicines that affect bleeding or clotting, including NSAIDs, aspirin, other blood thinners, and antiplatelet medicines.
  • Whether you are pregnant, planning pregnancy, or breastfeeding, especially if you have a mechanical heart valve.
  • Your age, since older adults (especially those 80 years and older) have an increased bleeding risk.
(1) (2) (4)

How to take enoxaparin sodium

  • Enoxaparin is given as an injection just under the skin (subcutaneously) in most uses, though some hospital indications use an intravenous injection -- always by or under the direction of a healthcare professional.
  • It must never be given by intramuscular injection.
  • Your exact dose and timing are individualised based on why you are taking it, your body weight, and your kidney function -- never adjust the dose or timing yourself.
  • If you are scheduled for spinal or epidural anesthesia or a spinal puncture, your care team will plan the timing of your enoxaparin doses carefully around the procedure because of the boxed-warning spinal/epidural blood clot risk -- in the UK, therapeutic doses require at least 24 hours before such a procedure, and in New Zealand the required gap is at least 12 hours after lower prophylactic doses or 24 hours after higher treatment doses.
(1)

Procedures and treatment changes

Tell the treating team before surgery, procedures, or any medicine change. Do not alter treatment without the responsible clinician. (1) (2) (3) (4) (5) (6)

Missed dose

Contact your care team immediately for guidance if a dose is missed -- do not give an extra dose or change the schedule yourself.

Overdose

Seek urgent medical attention for a suspected overdose. Signs of too much anticoagulant effect include unusual bruising, nosebleeds, blood in urine or stool, or unusually heavy bleeding from a cut or injection site. (1)

Side effects

Side effects and their urgency vary; report severe, persistent, or concerning symptoms.

Bruising, bleeding, or irritation at the injection site.

What to notice: Bruising, bleeding, or irritation at the injection site.

What to do: Discuss persistent or troublesome symptoms with the treating clinician or pharmacist. (1)

Low blood count (anemia).

What to notice: Low blood count (anemia).

What to do: Discuss persistent or troublesome symptoms with the treating clinician or pharmacist. (1)

Nausea and diarrhea.

What to notice: Nausea and diarrhea.

What to do: Discuss persistent or troublesome symptoms with the treating clinician or pharmacist. (1)

Elevation of liver enzyme (aminotransferase) blood test results.

What to notice: Elevation of liver enzyme (aminotransferase) blood test results.

What to do: Discuss persistent or troublesome symptoms with the treating clinician or pharmacist. (1)

Serious warnings

Signs of a spinal or epidural blood clot (hematoma) — boxed_warning

Symptoms: New or worsening back pain, numbness, tingling, weakness in the legs, or loss of control of bowel or bladder function, especially after spinal or epidural anesthesia or a spinal puncture.

Action: Seek emergency medical help immediately -- this can indicate a spinal or epidural blood clot pressing on the spinal cord, which can cause long-term or permanent paralysis if not treated urgently. (1)

Signs of major bleeding — boxed_warning_adjacent_serious

Symptoms: Unusual bruising, nosebleeds that won't stop, blood in urine or stool, coughing up blood, severe headache or sudden confusion (possible signs of bleeding in the brain), severe back or abdominal pain (possible sign of bleeding behind the abdomen), or bleeding from the gums.

Action: Contact your clinician or seek emergency care immediately -- enoxaparin carries a genuine risk of major hemorrhage, including fatal bleeding in the brain or abdomen. (1)

Signs of a low platelet count (thrombocytopenia), including heparin-induced thrombocytopenia (HIT/HITT) — high caution

Symptoms: Unusual bruising or small red/purple spots on the skin, unexplained bleeding, or new pain, swelling, discoloration, or coldness in an arm or leg (possible sign of a new clot).

Action: Your platelet count will be monitored before and during treatment; enoxaparin is generally stopped if the platelet count falls below 100,000/mm3. Report any unusual bruising, bleeding, or new limb symptoms to your care team promptly -- heparin-induced thrombocytopenia with thrombosis can cause organ damage, limb loss, or death if untreated. (1) (2)

Signs of a serious allergic reaction — emergency

Symptoms: Swelling of the face, lips, tongue, or throat; difficulty breathing; widespread rash or hives.

Action: Seek emergency medical help immediately. (1)

Interactions

  • Other medicines that affect bleeding or clotting -- including NSAIDs, aspirin and other antiplatelet medicines, warfarin, and other anticoagulants -- increase bleeding risk and increase the spinal/epidural hematoma risk if combined around the time of a spinal procedure. (1)
  • Enoxaparin must not be interchanged, unit for unit, with heparin or other low molecular weight heparins -- each has its own specific dosing. (1)

Pregnancy, breastfeeding, kidney/liver function, age

Pregnancy

Discuss with your clinician; pregnant women with a mechanical heart valve require especially close monitoring, since inadequate anticoagulation has been reported in this situation. (1) (2) (3) (4) (5) (6)

Breastfeeding

Discuss with your clinician before use while breastfeeding. (1) (2) (3) (4) (5) (6)

Children

Safety and efficacy have not been established in the pediatric population per UK regulator sources reviewed for this dossier. (1) (2) (3) (4) (5) (6)

Elderly

Older adults, especially those 80 years of age and older, have an increased risk of bleeding with enoxaparin and other low molecular weight heparins and should be monitored closely. (1) (2) (3) (4) (5) (6)

Hepatic Impairment

Use with caution and clinician guidance; not specifically quantified in the sources reviewed for this dossier. (1) (2) (3) (4) (5) (6)

Renal Impairment

Severe renal impairment (creatinine clearance under 30 mL/min) significantly increases enoxaparin exposure (approximately 65% higher) and requires dose reduction; bleeding risk rises as kidney function declines. (1) (2) (3) (4) (5) (6)

Monitoring

Before starting

  • Kidney function (creatinine clearance)
  • Body weight
  • Baseline platelet count
  • Review of other medicines affecting bleeding/clotting
  • Review of any planned spinal/epidural procedure

During treatment

  • Platelet count monitored before starting and regularly during treatment; enoxaparin generally discontinued if it falls below 100,000/mm3, since heparin-induced thrombocytopenia typically appears between the 5th and 21st day of treatment.
  • Kidney function reassessed as needed, since bleeding risk rises as kidney function declines.
  • Close monitoring for neurological signs (back pain, numbness, weakness, bowel/bladder changes) around the time of any spinal or epidural procedure.
(1) (2)

Storage

Store pre-filled syringes or vials as directed on the product label, typically at room temperature, protected from light, out of reach of children.

Study the drug class: Heparins and related parenteral anticoagulants

Professional information

Clinician-facing context only, sourced from the current US FDA prescribing information and UK/Canada regulator sources reviewed for this dossier; verify against the current full label before prescribing.

United States

Indication: VTE prophylaxis and treatment; acute coronary syndrome (adults)

Dose summary: Prophylaxis 40 mg SC once daily or 30 mg SC every 12 hours depending on surgery type; treatment 1 mg/kg SC every 12 hours or 1.5 mg/kg once daily; acute STEMI 30 mg IV bolus plus 1 mg/kg SC (under 75 years) or 0.75 mg/kg SC every 12 hours with no bolus (75 years and older).

Renal context: Severe renal impairment (CrCl <30 mL/min): reduce to 30 mg SC once daily (prophylaxis) or 1 mg/kg SC once daily (treatment). (1)

United Kingdom

Indication: VTE prophylaxis and treatment; acute coronary syndromes; hemodialysis circuit anticoagulation

Dose summary: Indication- and weight-based dosing per the current Clexane SmPC; spinal/epidural anesthesia contraindicated within 24 hours of a therapeutic dose.

Renal context: Severe renal impairment significantly increases exposure (approximately 65% higher); dose adjustment required. Not given intramuscularly. (2)

Mechanism of action

Hepatic guidance

Not specifically quantified in the sources reviewed for this dossier.

Overdose note

No specific universal antidote; protamine sulfate partially neutralises enoxaparin's anticoagulant effect (more effective against anti-IIa than anti-Xa activity); manage with supportive care and close monitoring for bleeding. (1)

Frequently asked questions

Why does enoxaparin have a boxed warning about spinal procedures?

Because, like other low molecular weight heparins, enoxaparin carries a genuine risk that a blood clot can form in or around the spine if it is given around the time of spinal or epidural anesthesia or a spinal puncture. This clot can press on the spinal cord and cause long-term or permanent paralysis, which is why your care team carefully times enoxaparin doses around any such procedure (with specific minimum gaps required in some countries) and monitors you closely afterward for warning signs. (1) (2)

Why is enoxaparin dosed by body weight and kidney function?

Because both affect how much enoxaparin stays in your body and how much bleeding risk you have. Severe kidney impairment significantly increases enoxaparin exposure, requiring a lower dose, and body weight affects dosing for the treatment indications. (1) (2)

Why do I need blood tests while taking enoxaparin?

Your platelet count is checked before starting and during treatment because enoxaparin can, in some people, cause a drop in platelets, including a rarer but serious form (heparin-induced thrombocytopenia with thrombosis) that typically appears between the 5th and 21st day of treatment. Treatment is generally stopped if the count falls below 100,000/mm3. (1) (2)

What is the mechanism of action of enoxaparin sodium?

Enoxaparin is a low molecular weight heparin produced by controlled depolymerisation of heparin, which potentiates antithrombin's inhibition of factor Xa and, to a lesser extent, thrombin (factor IIa), interrupting the coagulation cascade. (1)

What is the generic name of Enoxaparin?

The generic name is enoxaparin sodium. (1) (3)

What class of drug is enoxaparin sodium?

Enoxaparin is classed as: Anticoagulant (low molecular weight heparin, LMWH). (1) (3)

References

  1. LOVENOX (enoxaparin sodium injection) for subcutaneous and intravenous use -- full prescribing informationU.S. Food and Drug Administration / DailyMed (NIH), full prescribing information, Sanofi-Aventis · United States · accessed 2026-07-30 · source 1
  2. Clexane Pre-filled Syringes (enoxaparin sodium) -- Summary of Product Characteristicselectronic medicines compendium (emc), United Kingdom -- Sanofi · United Kingdom · accessed 2026-07-30 · source 2
  3. Inhixa, INN-enoxaparin sodium -- EPAR (centralised biosimilar authorisation)European Medicines Agency (EMA) -- centralised EU marketing authorisation, EPAR (biosimilar enoxaparin) · European Union · accessed 2026-07-30 · source 3
  4. LOVENOX (enoxaparin sodium) -- Product MonographHealth Canada product monograph, Sanofi-Aventis Canada · Canada · accessed 2026-07-30 · source 4
  5. CLEXANE enoxaparin sodium injection syringes -- multiple ARTG entries (e.g. 56711, 56709, 42965, 42962, 74173)Therapeutic Goods Administration (TGA), Australia · Australia · accessed 2026-07-30 · source 5
  6. Clexane/Clexane Forte -- New Zealand Data Sheet (CCDSv14/DSv22, 20 June 2022)Medsafe (New Zealand Medicines and Medical Devices Safety Authority) · New Zealand · accessed 2026-07-30 · source 6

Brand names by country

Single-ingredient enoxaparin sodium names are shown separately by country. Product availability, strengths, and supply rules can change; combination products are not included here.

Priority countries

United States

  • Lovenox60 mg/.6mL, 40 mg/.4mL, 30 mg/.3mL, 300 mg/3mL, 120 mg/.8mL, 80 mg/.8mL, 150 mg/mL, 100 mg/mL · sanofi-aventis u.s. llc

United Kingdom

  • Clexane / Clexane Forte (2)MHRA licensed emc smpc confirmed · 20 mg, 40 mg, 60 mg, 80 mg, 100 mg, 120 mg, 150 mg · Sanofi, Reading, UK (PL 04425/0187)

Canada

  • LOVENOX
  • LOVENOX HP

Australia

  • Clexane / Clexane Forte (5)TGA ARTG registered 1993-02-12 confirmed · 20 mg/0.2 mL, 40 mg/0.4 mL, 60 mg/0.6 mL, 100 mg/1 mL, 120 mg/0.8 mL, 80 mg/0.8 mL, 150 mg/1 mL · Sanofi-Aventis Australia Pty Ltd

New Zealand

  • Clexane / Clexane Forte (6)Medsafe current datasheet confirmed · 20 mg, 40 mg, 60 mg, 80 mg, 100 mg · Sanofi
View brands in additional countries.

European Union

Clexane (nationally authorised originator) (3), Inhixa (EMA-centralised biosimilar) (3)

This page provides general reference information about enoxaparin and is not a substitute for advice from the clinician managing your treatment. All dosing, timing around spinal/epidural procedures, and monitoring decisions should be made with your prescriber or care team.

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