Heparin (By injection)

Heparin (HEP-a-rin)

Prevents and treats blood clots. Also helps diagnose and treat bleeding disorders. This medicine is a blood thinner.

Brand Name(s):

BD PosiFlush Heparin Lock, Heparin Sodium Novaplus, Hepflush-10, PosiFlush Heparin, Simplist Heparin Sodium, Vasceze Heparin Lock Flush

There may be other brand names for this medicine.

When This Medicine Should Not Be Used:

This medicine is not right for everyone. You should not receive it if you had an allergic reaction to heparin, corn, or pork products. Tell your doctor if you have received heparin before and it caused immune system problems (HIT or HITT).

How to Use This Medicine:


  • Your doctor will prescribe your exact dose and tell you how often it should be given. This medicine is given through a needle placed in one of your veins or as a shot under your skin.
  • A nurse or other trained health professional will give you this medicine.
  • You may be taught how to give your medicine at home. Make sure you understand all instructions before giving yourself an injection. Do not use more medicine or use it more often than your doctor tells you to.
  • You will be shown the body areas where this shot can be given. Use a different body area each time you give yourself a shot. Keep track of where you give each shot to make sure you rotate body areas.
  • Use a new needle and syringe each time you inject your medicine.
  • Missed dose: Take a dose as soon as you remember. If it is almost time for your next dose, wait until then and take a regular dose. Do not take extra medicine to make up for a missed dose.
  • If you store this medicine at home, keep it at room temperature, away from heat, moisture, and direct light.
  • Throw away used needles in a hard, closed container that the needles cannot poke through. Keep this container away from children and pets.

Drugs and Foods to Avoid:

Ask your doctor or pharmacist before using any other medicine, including over-the-counter medicines, vitamins, and herbal products.

  • Some medicines and foods can affect how heparin works. Tell your doctor if you are using any of the following:
    • Digitalis, nicotine, nitrates, or nitroglycerin
    • Allergy medicine, including diphenhydramine
    • Blood thinner, including dicumarol or warfarin
    • NSAID or similar medicine that might cause bleeding, including aspirin, diclofenac, ibuprofen, indomethacin, naproxen, phenylbutazone, or celecoxib

Warnings While Using This Medicine:

  • Tell your doctor if you are pregnant or breastfeeding, or if you have liver disease, kidney disease, high blood pressure, a bleeding disorder, ulcers, diabetes, or cancer. Tell your doctor if you are allergic to sulfites.
  • This medicine may cause the following problems:
    • Serious bleeding
    • Blood clots, which may lead to stroke or heart attack
    • Heparin-induced thrombocytopenia (HIT or HITT), an immune system reaction that could happen several weeks after treatment ends
  • This medicine lowers the number of certain blood cells, so you may bleed or bruise more easily. Be careful to avoid injuries.
  • Tell any doctor or dentist who treats you that you are using this medicine. You may need to stop using this medicine several days before you have surgery or medical tests.
  • Your doctor will do lab tests at regular visits to check on the effects of this medicine. Keep all appointments.
  • Tell any doctor or dentist who treats you that you are using this medicine. This medicine may affect certain medical test results.
  • Keep all medicine out of the reach of children. Never share your medicine with anyone.

Possible Side Effects While Using This Medicine:

Call your doctor right away if you notice any of these side effects:

  • Allergic reaction: Itching or hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, trouble breathing
  • Dizziness, lightheadedness, or fainting
  • Chest pain, trouble breathing, or coughing up blood
  • Increased menstrual bleeding
  • Numbness or weakness on one side of your body, sudden or severe headache, or problems with vision, speech, or walking
  • Redness, pain, swelling, itching, blistering, sores, or rash where the needle is placed
  • Severe stomach pain, vomiting blood, bloody or black, or tarry stools
  • Trouble breathing
  • Unusual bleeding, bruising, or weakness

If you notice other side effects that you think are caused by this medicine, tell your doctor

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088

Last Updated: 11/6/2020

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