Heparin Side Effects, Important Information, Before Taking & How to Inject

Heparin is an anticoagulant that is used to prevent and treat blood clots that can be a result of specific medical procedures or medical conditions. It is also given to patients before surgery to reduce the danger of blood clots. It is also used in those who have atrial fibrillation to treat blood clots in the lungs. Heparin is also helpful in treating specific blood clotting disorders.


It is also used to avoid blood clots during dialysis, after surgery, during blood transfusions, when a person is not able to move for a long time, or when collecting blood samples. Heparin is particularly helpful in keeping the blood flowing smoothly by improving the performance of the anti-clotting protein in your body.


Side effects

Stop using Heparin if you have an allergic reaction to it in the form of nausea, sweating, itching, and swelling in your face, hives, vomiting or feeling faint.

Use of Heparin can cause you to bleed more easily which can be life-threatening. There might also be some internal bleeding. Get immediate medical attention if you have:

  • Any bleeding that does not stop
  • Severe pain in lower back, groin, or stomach
  • Unusual tiredness
  • Any unusual bruising or bleeding
  • Nausea, vomiting
  • Loss of appetite

Other signs of bleeding like blood in stools or urine, coughing up blood, nosebleed, black or tarry stools, or vomit that is similar to coffee grounds

While using Heparin, you might have bleeding episodes that might run for several weeks even after you stop using it. The risk of such bleeding episodes is higher in women who are over 60.


Stop using Heparin and seek medical help if you have:

  • Extreme weakness, drowsiness, or gasping for breath in infants
  • Watery eyes, fever, runny nose, chills
  • Signs of a blood clot – chest pain, problems with vision or speech, severe headache, sudden weakness or numbness, warmth or swelling in one or both legs, and wheezing.

Women over 60 years of age are more likely to have bleeding episodes while using Heparin.

Some severe side effects of Heparin are:

  • Bone pain
  • Swelling at injection site
  • Easily broken bones


How to use Heparin

Before starting Heparin, read the information leaflet carefully. Heparin is injected under the skin or into the vein by an experienced health provider. Avoid injecting it into a muscle. Heparin is available in many strengths and taking the wrong strength could become fatal. Make sure that you are using the correct strength and dosage before injecting.

Before injecting Heparin into a vein, flush the catheter with normal saline to avoid a drug interaction. Clean the injection area with rubbing alcohol before injecting Heparin. Inject in a different area to lessen injury to the skin. Do not use Heparin if you can see particles in it or if there is any discoloration.



Avoid using Heparin if you are allergic to it, or have other allergies, or have a low tolerance for pork products.

If you have a medical history of the following conditions, be sure to discuss them with your doctor:

  • Blood problems such as hemophilia, low platelet count
  • Recent surgery
  • High blood pressure
  • Liver disease
  • Heart problems such as heart attack or heart infection
  • Intestinal or stomach ulcers or tube drainage



Use caution while using sharp objects like nail cutters and razors to lower the chance of getting injured, cut, or bruised. Also, avoid activities like contact sports.

Use of Heparin can cause stomach bleeding. Drinking alcohol daily while you are taking this medicine also increases the risk of stomach bleeding. Limit your alcohol intake.