Consumer medicine information


Heparin sodium

Consumer Medicine Information

What is in this leaflet

This leaflet answers some common questions about Heparin Injection. It does not contain all the available information. It does not take the place of talking to your doctor or pharmacist.

All medicines have benefits and risks. Your doctor has weighed the risks of you using Heparin Injection against the benefits they expect it will have for you.

This medicine is likely to be used while you are at the clinic or in hospital. If possible, please read this leaflet carefully before this medicine is given to you. In some cases, this leaflet may be given to you after the medicine has been used.

If you have any concerns about using this medicine, ask your doctor or pharmacist.

Keep this leaflet. You may need to read it again.

What HEPARIN INJECTION is used for

Heparin Injection belongs to a group of medicines known as anticoagulants. Anticoagulants work by decreasing the clotting ability of your blood and help stop clots forming in the blood vessels.

Anticoagulants are sometimes called “blood thinners”, although they do not actually thin the blood. Heparin will not dissolve blood clots that have already formed, but it may prevent any clots that have already formed from becoming larger and causing serious problems.

Heparin Injection is used for prevention and treatment of diseases caused by blood clots such as in certain blood vessel, heart and lung conditions. It is also used to prevent blood clots from forming during surgery, dialysis or blood transfusions.

Heparin Injection may be used for the treatment of other conditions that are not mentioned above. Your doctor will be able to tell you about the specific condition for which you have been prescribed Heparin Injection.

This medicine is available only with a doctor’s prescription.

This medicine is not addictive.

Before you are given HEPARIN INJECTION

When you must not be given it

Do not use Heparin Injection if you:

  • have an allergy to heparin or pork products
  • have, or may have, a bleeding disease or a problem with your blood vessels
  • have a low blood platelet count

If you are not sure whether any of these apply to you, check with your doctor.

Before you are given it

Tell your doctor if:

  1. you have any allergies to:
  • any other medicine
  • any other substances, such as foods, preservatives or dyes
  1. you are pregnant or intend to become pregnant

When heparin is used in pregnant women, it can cause premature (early) delivery or harm your baby. Your doctor will discuss the possible risks and benefits of being given heparin during pregnancy.

  1. you are breast-feeding or plan to breast feed

Your doctor will discuss the possible risks and benefits of being given heparin whilst breast-feeding.

  1. you have or have had any medical conditions or procedures, especially the following:
  • heart problems or high blood pressure
  • blood diseases or bleeding problems
  • heavy or unusual menstrual periods
  • medical, surgical or dental procedure
  • stomach ulcer
  • liver disease
  • kidney disease
  • diabetes

Taking other medicines

Tell your doctor if you are taking any other medicines, including any that you buy without a prescription from your pharmacy, supermarket or health food shop.

Some medicines and heparin may interfere with each other. These include:

  • pain relieving medicines such as aspirin and ibuprofen
  • medicines for heart and circulation problems such as digitalis, glyceryl trinitrate, dipyridamole and epoprostenol
  • medicines for hayfever such as anti-histamines
  • medicines for rheumatoid arthritis such as hydroxychloroquine
  • anti-inflammatory medicines such as indometacin and phenylbutazone
  • nicotine
  • anti-clotting medicines such as aprotinin, warfarin, dextran, abciximab, eptifibatide, tirofiban, streptokinase, urokinase or alteplase
  • medicines which cause increased volume of urine (diuretics) such as spironolactone, triamterene and amiloride
  • potassium supplements including potassium containing salt substitutes
  • medicines for treating gout such as probenecid
  • medicines for reducing swelling of the body such as etacrynic acid
  • medicines for cancer treatment such as cytostatic drugs and asparaginase (colaspase)
  • antibiotics such as tetracyclines, cefamandole and penicillins
  • medicines used for epilepsy (seizures) such as valproic acid
  • medicines used for thyroid problems such as propylthiouracil
  • substances used to enhance the contrast of structures or fluids within the body in medical imaging
  • corticosteroids
  • insulin or other medicines used to treat diabetes known as “sulfonylureas” such as glipizide, glimepiride, glyburide, tolazamide and tolbutamide
  • medicines known as “benzodiazepines” such as chlordiazepoxide, diazepam, oxazepam
  • propanolol.

Your doctor and pharmacist have more information on medicines to be careful with or avoid while using this medicine.

Your doctor will advise you about continuing to take other medicines while you are receiving Heparin Injection.


How it is given

Heparin Injection can be injected under the skin or into a vein. Sometimes it may be diluted and given to you as a slow injection into one of your veins (this is called an intravenous infusion). Heparin Injection must only be given by a doctor or nurse.

How much is given

Your doctor will decide what dose, how often and how long you will receive Heparin Injection. This depends on your condition and other factors, such as age, blood tests, method it is being given and whether or not other medicines are being given at the same time.

To prevent clots forming, you will usually be given a deep injection under the skin 2 hours before surgery and every 8 – 12 hours for up to a week after surgery. This will depend on your condition.

To help clots that have already formed, you will be given Heparin Injection either as a continuous or intermittent infusion into the vein. Your doctor may also choose to inject Heparin Injection under the skin after giving you the first dose by an intravenous injection.

If you are given too much (overdose)

This rarely happens as Heparin Injection is administered under the care of a highly trained doctor.

However, if you are given too much heparin, you may experience some of the effects listed under “Side effects” below.

Your doctor has information on how to recognise and treat an overdose. Ask your doctor if you have any concerns.

In the case of an overdose, immediately tell your doctor or telephone the Poisons Information Centre (phone 13 11 26) for advice, or go to Accident and Emergency at your nearest hospital if you have side effects after being given Heparin Injection. You may need urgent medical attention.

While you are given HEPARIN INJECTION

Things you must do

If you are about to be started on any new medicine, remind your doctor and pharmacist that you are being given Heparin Injection.

Tell any other doctors, dentists, and pharmacists who treat you that you are being given this medicine.

If you are going to have surgery, tell the surgeon or anaesthetist that you are being given this medicine. It may affect other medicines used during surgery.

If you are about to have any blood tests, tell your doctor that you are being given this medicine. It may interfere with the results of some tests.

Things to be careful of

Be careful driving or operating machinery until you know how Heparin Injection affects you. This medicine is not expected to affect your ability to drive a car or operate machinery. However, if you experience dizziness, light-headedness, tiredness or drowsiness, do not drive, operate machinery or do anything else that could be dangerous.

If you have any serious, physical accidents once you leave hospital, advise your treating doctor or nurse that you have been given this medicine recently.

Side effects

Tell your doctor or nurse as soon as possible if you do not feel well while you are being given heparin. Like other medicines, heparin can cause some side effects. If they occur, most are likely to be minor or temporary. However, some may be serious and need medical attention.

Ask your doctor or nurse to answer any questions you may have.

Do not be alarmed by this list of possible side effects. You may not experience any of them.

Tell your doctor or nurse as soon as possible if you notice any of the following:

  • change in skin colour, or pain around the injection site
  • fever
  • chills
  • runny nose
  • watering eyes
  • nausea and vomiting
  • headache
  • itchy soles of the feet

These are side effects of heparin. Mostly these are mild and short-lived.

Tell your doctor or nurse immediately if you experience any of the following:

  • any changes in skin colour or pain around the injection site, or the skin starts to swell, gets warm/red, becomes numb or starts to blister
  • bleeding or bruising more easily than normal e.g. unexplained nosebleeds, heavy menstrual periods, bleeding from gums when brushing teeth
  • blood in urine or stools, vomiting of blood
  • If you drink heavily you have a greater risk of bleeding compared to moderate drinkers or non-drinkers. Elderly patients (older than 60 years of age), particularly women, have a greater risk of bleeding.
  • abdominal or stomach pain, chest pain, irregular, fast or fluttering heartbeat, muscle weakness or numbness in limbs, nausea and vomiting
  • signs of allergy such as a rash, itching, hives on the skin, swelling of the face, lips, tongue or other parts of the body, shortness of breath, wheezing or trouble breathing
  • numbness, pain, tingling or muscle weakness, abnormal function or loss of control of your bowel or urine
  • persistent painful erection

These side effects are serious. You may need urgent medical attention.

Other side effects not listed above may also occur in some patients. If you notice any other effects, check with your doctor. Some side effects may only be seen by your doctor.



Heparin Injection will be stored in the pharmacy or on the ward. The injection is kept in a cool dry place, where the temperature stays below 25°C.

Product description

What it looks like

Heparin Injection is a clear, colourless to straw coloured solution in a plastic ampoule.


Heparin Injection contains heparin sodium 1000IU/mL or 5000IU/mL in water for injections. It does not contain a preservative.


Pfizer Australia Pty Ltd
Sydney NSW
Toll Free Number: 1800 675 229

This leaflet was prepared in March 2021.

AUST R 49232 – Heparin Injection – 5,000IU/5mL (sterile) – Steriluer® ampoule (50’s)

AUST R 49232 – Heparin Injection – 5,000IU/5mL (sterile) – Steriluer® ampoule (10’s)

AUST R 49236 – Heparin Injection – 25,000IU/5mL (sterile) – Steriluer® ampoule (50’s)

® Registered trademark.

Published by MIMS May 2021