Heparin is used to prevent blood clots from forming in people who have certain medical conditions or who are undergoing certain medical procedures that increase the chance that clots will form. Heparin is also used to stop the growth of clots that have already formed in the blood vessels, but it cannot be used to decrease the size of clots that have already formed. Heparin is also used in small amounts to prevent blood clots from forming in catheters (small plastic tubes through which medication can be administered or blood drawn) that are left in veins over a period of time. Heparin is in a class of medications called anticoagulants ('blood thinners'). It works by decreasing the clotting ability of the blood.
Heparin comes as a solution (liquid) to be injected intravenously (into a vein) or deeply under the skin and as a dilute (less concentrated) solution to be injected into intravenous catheters. Heparin should not be injected into a muscle. Heparin is sometimes injected one to six times a day and sometimes given as a slow, continuous injection into the vein. When heparin is used to prevent blood clots from forming in intravenous catheters, it is usually used when the catheter is first put in place, and every time that blood is drawn out of the catheter or medication is given through the catheter.
Heparin may be given to you by a nurse or other healthcare provider, or you may be told to inject the medication by yourself at home. If you will be injecting heparin yourself, a healthcare provider will show you how to inject the medication. Ask your doctor, nurse, or pharmacist if you do not understand these directions or have any questions about where on your body you should inject heparin, how to give the injection, or how to dispose of used needles and syringes after you inject the medication.
If you will be injecting heparin yourself, follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Use heparin exactly as directed. Do not use more or less of it or use it more often than prescribed by your doctor.
Heparin solution comes in different strengths, and using the wrong strength may cause serious problems. Before giving an injection of heparin, check the package label to make sure it is the strength of heparin solution that your doctor prescribed for you. If the strength of heparin is not correct do not use the heparin and call your doctor or pharmacist right away.
Your doctor may increase or decrease your dose during your heparin treatment. If you will be injecting heparin yourself, be sure you know how much medication you should use.
Heparin is also sometimes used alone or in combination with aspirin to prevent pregnancy loss and other problems in pregnant women who have certain medical conditions and who have experienced these problems in their earlier pregnancies. Talk to your doctor or pharmacist about the risks of using this medication to treat your condition.
This medication may be prescribed for other uses; ask your doctor or pharmacist for more information.
Unless your doctor tells you otherwise, continue your normal diet.
If you will be injecting heparin yourself at home, talk to your doctor about what you should do if you forget to inject a dose.
redness, pain, bruising, or sores at the spot where heparin was injected
unusual bruising or bleeding
vomit that is bloody or looks like coffee grounds
stool that contains bright red blood or is black and tarry
blood in urine
chest pain, pressure, or squeezing discomfort
discomfort in the arms, shoulder, jaw, neck, or back
coughing up blood
sudden severe headache
lightheadedness or fainting
sudden loss of balance or coordination
sudden trouble walking
sudden numbness or weakness of the face, arm or leg, especially on one side of the body
sudden confusion, or difficulty speaking or understanding speech
difficulty seeing in one or both eyes
purple or black skin discoloration
pain and blue or dark discoloration in the arms or legs
itching and burning, especially on the bottoms of the feet
shortness of breath
difficulty breathing or swallowing
painful erection that lasts for hours
Heparin may cause osteoporosis (condition in which the bones become weak and may break easily), especially in people who use the medication for a long time. Talk to your doctor about the risks of using this medication.
Heparin may cause other side effects. Call your doctor if you have any unusual problems while using this medication.
If you will be injecting heparin at home, your healthcare provider will tell you how to store the medication. Follow these directions carefully. Be sure to keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom). Do not freeze heparin. Throw away any medication that is outdated or no longer needed. Talk to your pharmacist about the proper disposal of your medication.
In case of overdose, call your local poison control center at 1-800-222-1222. If the victim has collapsed or is not breathing, call local emergency services at 911.
blood in urine
black, tarry stools
red blood in stools
vomit that is bloody or looks like coffee grounds
Keep all appointments with your doctor and the laboratory. Your doctor will order certain lab tests to check your body's response to heparin. Your doctor may ask you to check your stool for blood using an at-home test.
Before having any laboratory test, tell your doctor and the laboratory personnel that you are using heparin.
Do not let anyone else use your medication. Ask your pharmacist any questions you have about refilling your prescription.
It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.
Last Revised - 08/15/2013
AHFS® Consumer Medication Information. © Copyright, 2015. The American Society of Health-System Pharmacists, Inc., 7272 Wisconsin Avenue, Bethesda, Maryland. All Rights Reserved. Duplication for commercial use must be authorized by ASHP.