Sounds like 'HEP-a-rin'

Key points about heparin

  • Heparin is an anticoagulant. It is used to treat and prevent blood clots, which can block your blood vessels.
  • Heparin is mostly used in hospital.
  • Find out how to use it safely and possible side effects.
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Heparin is known as an anticoagulantAnticoagulants are often referred to as ‘blood thinners’ but they actually work by interrupting the clot-forming process and increasing the time it takes for blood clots to form. This helps prevent blood clots from forming and stops existing clots from growing bigger.

Heparin is used to prevent blood clots after major surgeries such as hip or knee surgery, or abdominal surgery. It is also used if a blood clot has already formed, such as in your heart (heart attack), leg (deep vein thrombosis) or lung (pulmonary embolism).      

Heparin is also used to prevent blood clots from forming in intravenous (IV) catheters. It is usually used when the catheter is first put in place and every time blood is drawn out of the catheter or medicine is given through the catheter.

Heparin is given by injection into a vein (intravenous) or under your skin (subcutaneous).  

Heparin is mostly used in hospital. If you are given heparin to inject yourself at home, your healthcare professional will teach you how to prepare and use it. Here are a few tips on how to use heparin safely:

  • Use the exact dose your doctor tells you to.
  • You will be shown where the injection can be given. 
  • Use a different place each time you give yourself an injection to stop your skin from hardening. 
  • Call your doctor or nurse if you have redness, swelling, burning or pain where you injected the heparin.
  • Use a new needle and syringe each time.
  • If you miss a dose contact your doctor right away. 
  • It is important to let health professionals know that you are taking heparin. This includes your dentist, pharmacist, podiatrist and nurse.
  • You may need to stop using this medicine for several days before having surgery, dental appointments or medical tests.
  • You will need to have regular blood tests and doctor's visits while you are using heparin. 

Like all medicines, heparin can causes side effects, but not everyone gets them. 

Side effects What should I do?
  • You will bleed easily
  • Use a soft toothbrush, waxed dental floss and an electric razor.
  • Avoid sharp objects and fall risks (such as climbing a ladder).
  • Pain or bruising at the injection site 
  • Call your doctor if you have redness, swelling, burning or pain where you injected the medicine.
  • Signs of bleeding, such as dark urine (pee), black stools (poo), bad headache, confusion, vision changes, dizziness, fainting, weakness or numbness
  • Tell your doctor immediately or phone Healthline 0800 611 116.
  • Signs of an allergic reaction, such as skin rashes, itching, blisters, swelling of your face, lips or mouth, or problems breathing
  • Tell your doctor immediately or phone Healthline 0800 611 116.
Did you know that you can report a side effect to a medicine to CARM (Centre for Adverse Reactions Monitoring)? Report a side effect to a product(external link)

Heparin should not be taken with some other medicines and herbal supplements. Tell your doctor or pharmacist about all medicines you are taking (including over-the-counter medicines), herbal and complementary medicines, and recreational drugs. Your doctor or pharmacist will be able to check for any interactions. 

The following links provide further information on heparin. Be aware that websites from other countries may contain information that differs from New Zealand recommendations.

Heparin Injection(external link) Medsafe Consumer Information, NZ
Heparin (intravenous route, subcutaneous route)(external link) Mayo Clinic, US

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Credits: Sandra Ponen, Pharmacist, Healthify He Puna Waiora. Healthify is brought to you by Health Navigator Charitable Trust.

Reviewed by: Maya Patel, MPharm PGDipClinPharm, Auckland

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