Heparin - Use & side effects

Heparin is an anticoagulant (blood thinner) that prevents the formation of blood clots.

Heparin is injected under the skin or into a vein through an IV. You may be shown how to use injections at home.

Do not use heparin injection to flush (clean out) an intravenous (IV) catheter. A separate heparin product is available to use as catheter lock flush. Using the wrong type of heparin to flush a catheter can result in fatal bleeding.

You should not use heparin if you have uncontrolled bleeding or a severe lack of platelets in your blood.

Heparin increases your risk of bleeding, which can be severe or life-threatening. You will need frequent tests to measure your blood-clotting time.

Certain medicines can increase your risk of bleeding while you are using heparin, do not start to use a new medicine or supplement before talking to your doctor.

Call your doctor for instructions if you miss a dose of heparin.

Get emergency medical help if you have signs of an allergic reaction to heparin: nausea, vomiting, sweating, hives, itching, trouble breathing, swelling of your face, lips, tongue, or throat, or feeling like you might pass out.

Seek emergency medical attention if you have:

  • any unusual bleeding or bruising;
  • severe pain in your stomach, lower back, or groin;
  • swelling or bruising in your lower stomach or groin area;
  • nausea, vomiting, loss of appetite;
  • unusual tiredness;
  • any bleeding that will not stop; or
  • other signs of bleeding, such as a nosebleed, blood in your urine or stools, black or tarry stools, or coughing up blood or vomit that looks like coffee grounds.

Stop using heparin and call your doctor at once if you have:

  • signs of a blood clot – sudden numbness or weakness, severe headache, slurred speech, problems with speech or vision, chest pain, sudden cough, wheezing, swelling or warmth in one or both legs;
  • fever, chills, runny nose, or watery eyes;
  • trouble breathing; or
  • (in an infant) extreme drowsiness, weakness, or gasping for breath.

Women over 60 years of age may be more likely to have bleeding episodes while using heparin.

Common heparin side effects may include:

  • mild pain, redness, warmth, or skin changes where the medicine was injected;
  • mild itching of your feet; or
  • bluish-colored skin.
* The Content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.