Heparin Injection (Heparin Sodium)

Complete patient guide for uses, dosage, side effects, and safety information

Prescription Required

Quick Facts

Generic Name
heparin sodium
Drug Class
anticoagulant (blood thinner)
Used For
preventing and treating blood clots
How Taken
injection under the skin, into a vein, or as a slow drip into a vein

What Is Heparin Injection Used For?

Heparin Injection contains heparin sodium, which is derived from pig products. It belongs to a group of medicines called anticoagulants that work by decreasing your blood’s ability to clot, helping to prevent blood clots from forming.

Primary Uses

Heparin is used to prevent and treat blood clots in vessels that have started to clog up, including conditions like deep vein thrombosis (DVT) and other blood vessel, heart and lung conditions. It’s also used to prevent blood clots from forming during and after surgery, kidney dialysis, blood transfusions or similar procedures.

How It Works

Anticoagulants are sometimes called ‘blood thinners’, although they don’t actually thin your blood. Heparin won’t dissolve blood clots that have already formed, but it may prevent existing clots from becoming larger and causing serious problems.

Good to know: Heparin doesn’t actually thin your blood – it just reduces its ability to form clots

How to Take Heparin Injection

Heparin Injection is given by a doctor or nurse in a hospital setting. It cannot be self-administered at home.

Administration Methods

Heparin may be given as an injection under the skin (subcutaneously), by injection into a vein, or through a slow infusion ‘drip’ into a vein (intravenously). It should never be injected into muscle. Your doctor will decide what dose you receive, how often, and for how long you’ll receive treatment.

Important: Heparin must only be given by a doctor or nurse – it’s not for self-administration

Available Tablet Strengths

5,000 IU / 5 mL
5,000 IU / 5 mL Tablet Clear, colourless to straw-coloured, Solution in plastic ampoules • AUST R 49232
25,000 IU / 5 mL
25,000 IU / 5 mL Tablet Clear, colourless to straw-coloured, Solution in plastic ampoules • AUST R 49236

Side Effects

Like all medications, this medicine can cause side effects. Most are mild and temporary, but some require medical attention.

Common Side Effects

These side effects occur relatively frequently and usually don’t require emergency care:

  • Pain or bruising at injection site
  • Small lumps under the skin
  • Hair loss
  • Increased cholesterol
  • Receding gums
  • Brittle nails
  • Weaker hand grip
  • Back pain
  • Stooping posture (early signs of osteoporosis)

Seek immediate medical attention if you experience:

  • Allergic reactions (rash, swelling, breathing difficulties)
  • Unusual or increased bleeding (nosebleeds, heavy periods, bleeding gums)
  • Blood in urine or stool
  • Severe back pain with weakness or numbness
  • Severe headache with nausea, vomiting, confusion
  • Chest tightness or pain
  • Difficulty breathing
  • Signs of stroke (numbness, weakness, speech problems)
  • Very low blood pressure (shock)
  • Muscle weakness with heart rhythm problems
  • Severe abdominal pain

Important Warnings

There are several important conditions and situations where heparin should not be used or requires special caution.

Who Should Not Take Heparin Injection

Do not use heparin if you’re allergic to heparin, medicines derived from heparin, pork products, or any ingredients in the medicine. Also avoid if you have conditions where bleeding may be a problem, such as hemophilia, fragile capillaries, tumors, stroke (bleeding on the brain), heart inflammation, very high blood pressure, low blood platelet count, stomach or gut ulcers, severe kidney or liver disease, or very recent major surgery involving the eyes, brain or spinal cord.

Medical Conditions to Discuss

Tell your doctor if you have asthma or allergies, high blood pressure, ulcers, heart problems, cancer, diabetes, blood disorders, infections, liver or kidney disease, eye diseases, recent medical/surgical/dental procedures, scheduled procedures in coming weeks, gut drainage tubes, or heavy/unusual menstrual periods.

Pregnancy and Breastfeeding

Tell your doctor if you’re pregnant or breastfeeding. When used in pregnant women, heparin may cause premature delivery or harm your baby. Discuss the risks and benefits with your doctor. Tell your doctor if you have a history of miscarriage or recently had a baby.

Elderly Patients: Heparin should be used with caution in elderly patients, especially those 60 years and above, as they may be at increased risk of bleeding complications

Drug Interactions

Many medicines can interfere with heparin and affect how it works. Heparin treatment may also increase potassium levels in your blood.

Alcohol and smoking: Tell your doctor if you’re a smoker or heavy drinker, as these can affect heparin’s effectiveness and increase bleeding risk

  • Other heparin-derived medicines (dalteparin sodium, enoxaparin sodium)
  • Other blood thinners (warfarin)
  • NSAIDs (aspirin, naproxen, ibuprofen, diclofenac)
  • Platelet inhibitors (clopidogrel, prasugrel, ticagrelor)
  • Clot-dissolving medicines (alteplase, tenecteplase, apixaban, rivaroxaban, dabigatran)
  • Corticosteroids (prednisone, prednisolone, dexamethasone)
  • Hydroxychloroquine
  • Cancer medicines (cytarabine, daunorubicin, fluorouracil, methotrexate)
  • Some antibiotics (penicillin, cefamandole, tetracyclines)
  • Antihistamines (especially diphenhydramine)
  • Digoxin
  • Potassium-raising medicines
  • Diabetes medicines (sulfonylureas)
  • Benzodiazepines (diazepam, oxazepam, midazolam)

Alcohol & Driving

Heparin can affect your ability to drive and may interact dangerously with alcohol.

Alcohol

If you’re a heavy alcohol drinker, you have a greater risk of major bleeding associated with heparin compared to moderate drinkers or non-drinkers. Always tell your doctor about your alcohol consumption.

Driving and Operating Machinery

Don’t drive or use machines until you know how heparin affects you. In some cases, heparin may cause drowsiness, tiredness, dizziness, confusion, or anxiety/agitation.

Storage

Heparin Injection will be stored in the hospital pharmacy or on the ward under the correct conditions. You don’t need to worry about storage as this medication is only given in healthcare settings.

Overdose Information

Since heparin is given in a hospital under close medical supervision, overdose is very unlikely. However, if you’re concerned you may have received too much, tell your doctor or nurse immediately. Signs of overdose include abnormal bleeding from bowel movements, urine, under the skin, from the nose, unusual bruising, or coughing up blood.

Frequently Asked Questions

Heparin works quickly to prevent blood clots from forming, but it won’t dissolve clots that have already formed. Your doctor will monitor your blood clotting factors to ensure it’s working effectively.

No, Heparin Injection must only be given by a doctor or nurse in a healthcare setting. It cannot be self-administered at home.

Heparin may cause premature delivery or harm your baby when used during pregnancy. You must discuss the risks and benefits with your doctor, especially if you have a history of miscarriage.

Watch for unusual bleeding such as nosebleeds, bleeding gums, blood in urine or stool, excessive bleeding from wounds, or unusual bruising. Also report severe headaches, numbness, or vision changes immediately.

Heavy alcohol drinking increases your risk of major bleeding with heparin. Tell your doctor about your alcohol consumption so they can monitor you appropriately.

Some patients may experience osteoporosis (bone weakening) with long-term use, which can cause symptoms like back pain, stooping posture, weaker grip, and brittle nails.

Always tell any doctor, dentist, or healthcare provider that you’ve recently received heparin, as it affects blood clotting and may interfere with procedures or other medications.

Important Disclaimer

This information is intended for general educational purposes only and should not be considered medical advice. Always consult your healthcare provider or pharmacist before starting, stopping, or changing any medication.

If you think you may have a medical emergency, call your doctor or emergency services immediately.