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How to administer heparin injections at home using a pre-filled syringe

Patient information A-Z

Who is the leaflet for? What is its aim?

This leaflet explains how you should go about injecting heparin yourself. Your doctor has prescribed the medicine for you and you will have been given permission to do so. You should read the Patient Information Leaflet included in the medication pack before administering the heparin. A member of your household or your friend can help you in giving this medication.

What is heparin?

Heparin is a type of medication that stops the blood from clotting. You administer heparin to yourself at home by injection directly into the fleshy part of your stomach or thigh.

Why have I been prescribed heparin?

You are taking warfarin to thin your blood and avoid clot formation and are going to undergo an operation. Some examples of these procedures are:

  • Tenckhoff insertion
  • Arterio Venous Fistula creation
  • Central venous catheter (or neckline) insertion as access for haemodialysis.

We don’t want you to bleed. So, instead of taking Warfarin, you can have a heparin injection.


You have to stop taking warfarin and inject the heparin for five days before the operation. The operating surgeon or the renal doctor will give you instructions about when you should re-start taking warfarin. You should clarify with the doctor or nurses in the hospital before going home when this will be. You can normally restart warfarin is on the day after the operation, depending on the outcome.

Why do I need heparin injections?

Developing a blood clot can be dangerous. Sometimes these clots can move and travel to your lungs, which may result in a life-threatening condition.

How does heparin work?

The heparin injections work by slightly decreasing the chances of your blood clotting and thus minimising the risk of a clot forming

Other medications

If you are taking other blood thinning medication, please tell the doctor who prescribed the heparin.

How is it given?

Before giving the injection, make sure you wash your hands with soap and water. Dry your hands well.


1. Get yourself into a comfortable position sitting down where you can see your tummy.

figure lying down

2. Choose an injection site on either your tummy or outer areas of your left or right thigh (see shaded areas). Your tummy is usually best as the injection site. It is important that you change the site each time.

Diagram of thighs

3. Pick up the syringe. Grasp the tip of the Needle-Trap and bend it away from the syringe.

Needle with guard on

4. Carefully remove the syringe from the plastic container. Remove the needle guard. Ensure the needle does not touch anything. It is now ready for use.

Needle with guard off

5. Do not attempt to replace the needle shield as damage to the needle may result. You will notice an air bubble in the syringe. It is supposed to be there and it is important not to press the plunger just yet, as some of the medicine may be lost.

Syringe being inserted

6. Hold the syringe in one hand and, with the other hand, gently pinch a fold of skin with its fatty tissue (see the shaded areas above) between your thumb and index finger. This will be the injection site.

Syringe with and without guard - side by side

7. Hold the syringe at a 90 degree angle and keep pinching the fold of skin. Ensure the needle is fully inserted and press the plunger to inject. Once all the medicine has been injected, release the fold of skin and pull the needle out. If there is any oozing of blood at the injection site, apply gentle pressure. Do not rub the injection site as this may encourage bruising.

Needle-Trap being activated

8. Once the injection is complete, activate the Needle-Trap with one hand by forcing the needle into the trap against a hard, stable surface so that it locks into place. An audible ‘click’ will be heard. The needle is bent until the syringe exceeds a 45 degree angle with the flat surface to render it permanently unusable.

9. Dispose of the syringe immediately into your yellow sharps bin. Keep your sharps bin out of reach of other people. When the sharps bin is almost full, please speak to your GP or the clinic for disposal.

Syringe being dumped in bin

Risks and complications

It is normal to find that small bruises or small lumps are caused where the injection is given; these will disappear. Avoid any sore, red or bruised areas when giving injections, and try to alternate sites for the injections. If you do get any local skin rash at the site of the injection, please inform your doctor or nurse.

Important information

It is still important to be aware of the symptoms of blood clots. These are:

  • swollen area of the leg
  • pain / tenderness of the leg
  • increased warmth to the leg
  • red or discoloured area to the leg
  • acute shortness of breath
  • chest pain worsening on taking a deep breath
  • coughing up blood

It is important that if you can move around, you do so as much as possible. If you experience any of the above symptoms, please get medical advice immediately. To reduce the chance of your developing a blood clot, it is essential that you complete the full course of injections.

Please make sure that the container that you have been given for the disposal of your syringes is returned to the hospital or chemist for safe disposal after your course of treatment has finished.

Who do I contact if I have any concerns?

If you have any concerns or questions, please contact the doctor or a nurse who prescribed the medication. Telephone the inpatient dialysis unit here at Addenbrooke’s Hospital on 01223 245342.Tell the nurse that you would like to speak to the renal doctor. Be ready to give your hospital or NHS number. Alternatively, contact 01223 400182 and speak to the renal clinical nurse specialist.

You can also report side effects directly via the Yellow Card Scheme at By reporting the side effects, you can help provide more information on the safety of this medicine.

Prescribed Medication: ____________________

Dose: _________________________________

Day 1 Day 2 Day 3 Day 4 Day 5 Day 6 Day 7
Day 1 Day 2 Day 3 Day 4 Day 5 Day 6 Day 7

We are smoke-free

Smoking is not allowed anywhere on the hospital campus. For advice and support in quitting, contact your GP or the free NHS stop smoking helpline on 0800 169 0 169.

Other formats

Help accessing this information in other formats is available. To find out more about the services we provide, please visit our patient information help page (see link below) or telephone 01223 256998.

Contact us

Cambridge University Hospitals
NHS Foundation Trust
Hills Road, Cambridge

Telephone +44 (0)1223 245151