In the U.S.—

In Canada—

• Anticoagulant

Heparin ( HEP-a-rin) is an anticoagulant. It is used to decrease the clotting ability of the blood and help prevent harmful clots from forming in the blood vessels. This medicine is sometimes called a blood thinner, although it does not actually thin the blood. Heparin will not dissolve blood clots that have already formed, but it may prevent the clots from becoming larger and causing more serious problems.

Heparin is often used as a treatment for certain blood vessel, heart, and lung conditions. Heparin is also used to prevent blood clotting during open-heart surgery, bypass surgery, and dialysis. It is also used in low doses to prevent the formation of blood clots in certain patients, especially those who must have certain types of surgery or who must remain in bed for a long time.

Heparin is available only with your doctor's prescription, in the following dosage form:

Parenteral
• Injection (U.S. and Canada)

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For heparin, the following should be considered:

Allergies—Tell your doctor if you have ever had any unusual or allergic reaction to heparin, to beef, or to pork. Also tell your health care professional if you are allergic to any other substances, such as foods, preservatives, or dyes.

Pregnancy—Heparin has not been shown to cause birth defects or bleeding problems in the baby. However, use during the last 3 months of pregnancy or during the month following the baby's delivery may cause bleeding problems in the mother.

Breast-feeding—Heparin does not pass into the breast milk. However, heparin can rarely cause bone problems in the nursing mother. This effect has been reported to occur when heparin is used for 2 weeks or more. Be sure to discuss this with your doctor.

Children—Heparin has been tested in children and, in effective doses, has not been shown to cause different side effects or problems than it does in adults.

Older adults—Bleeding problems may be more likely to occur in elderly patients, especially women, who are usually more sensitive than younger adults to the effects of heparin.

Other medicines—Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking heparin, it is especially important that your health care professional know if you are taking any of the following:

• Aspirin or
• Carbenicillin by injection (e.g., Geopen) or
• Cefamandole (e.g., Mandol) or
• Cefoperazone (e.g., Cefobid) or
• Cefotetan (e.g., Cefotan) or
• Dipyridamole (e.g., Persantine) or
• Divalproex (e.g., Depakote) or
• Medicine for inflammation or pain, except narcotics, or
• Medicine for overactive thyroid or
• Pentoxifylline (e.g., Trental) or
• Plicamycin (e.g., Mithracin) or
• Probenecid (e.g., Benemid) or
• Sulfinpyrazone (e.g., Anturane) or
• Ticarcillin (e.g., Ticar) or
• Valproic acid (e.g., Depakene)—Using any of these medicines together with heparin may increase the risk of bleeding

• Also, tell your doctor if you are now receiving any kind of medicine by intramuscular (IM) injection.

• Allergies or asthma (history of)—The risk of an allergic reaction to heparin may be increased

• Blood disease or bleeding problems or
• Colitis or stomach ulcer (or history of) or
• Diabetes mellitus (sugar diabetes) (severe) or
• High blood pressure (hypertension) or
• Kidney disease or
• Liver disease or
• Tuberculosis (active)—The risk of bleeding may be increased

Also, tell your doctor if you have received heparin before and had a reaction to it called thrombocytopenia, or if new blood clots formed while you were receiving the medicine.

In addition, it is important that you tell your doctor if you have recently had any of the following conditions or medical procedures:

• Childbirth or
• Falls or blows to the body or head or
• Heavy or unusual menstrual bleeding or
• Insertion of intrauterine device (IUD) or
• Medical or dental surgery or
• Spinal anesthesia or
• X-ray (radiation) treatment—The risk of serious bleeding may be increased

If you are using these injections at home, make sure your doctor has explained exactly how this medicine is to be given.

To obtain the best results without causing serious bleeding, use this medicine exactly as directed by your doctor. Be certain that you are using the right amount of heparin, and that you use it according to schedule . Be especially careful that you do not use more of it, do not use it more often, and do not use it for a longer time than your doctor ordered.

Your doctor should check your progress at regular visits . A blood test must be taken regularly to see how fast your blood is clotting so that your doctor can decide on the proper amount of heparin you should be receiving each day.

Dosing—

The dose of heparin will be different for different patients and must be determined by your doctor. The dose you receive will be based on the type of heparin you receive, the condition for which you are receiving heparin, and your body weight.

Missed dose—

If you miss a dose of this medicine, use it as soon as possible. However, if it is almost time for your next dose, do not use the missed dose at all and do not double the next one. Doubling the dose may cause bleeding. Instead, go back to your regular dosing schedule. It is best to keep a record of each dose as you use it to avoid mistakes. Be sure to give your doctor a record of any doses you miss. If you have any questions about this, check with your doctor.

Storage—

To store this medicine:

• Keep out of the reach of children.
• Store away from heat and direct light.
• Keep the medicine from freezing.
• Do not keep outdated medicine or medicine no longer needed. Be sure that any discarded medicine is out of the reach of children.

Do not take aspirin while using this medicine. Many nonprescription (over-the-counter [OTC]) medicines and some prescription medicines contain aspirin. Check the labels of all medicines you take. Also, do not take ibuprofen unless it has been ordered by your doctor. In addition, there are many other medicines that may change the way heparin works or increase the chance of bleeding if they are used together with heparin. It is best to check with your health care professional before taking any other medicine while you are using heparin.

Tell all medical doctors and dentists you visit that you are using this medicine.

It is recommended that you carry identification stating that you are using heparin. If you have any questions about what kind of identification to carry, check with your health care professional.

While you are using this medicine, it is very important that you avoid sports and other activities that may cause you to be injured. Report to your doctor any falls, blows to the body or head, or other injuries, since serious bleeding inside the body may occur without your knowing about it.

Take special care in brushing your teeth and in shaving. Use a soft toothbrush and floss gently. Also, it is best to use an electric shaver rather than a blade.

Since many things can affect the way your body reacts to this medicine, you should always watch for signs of unusual bleeding. Unusual bleeding may mean that your body is getting more heparin than it needs.

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following signs and symptoms of bleeding inside the body occur:

• Abdominal or stomach pain or swelling;  back pain or backaches;  blood in urine;  bloody or black, tarry stools;  constipation ;  coughing up blood;  dizziness ;  headaches (severe or continuing);  joint pain, stiffness, or swelling;  vomiting of blood or material that looks like coffee grounds 

Also, check with your doctor immediately if any of the following side effects occur, since they may mean that you are having a serious allergic reaction to the medicine:

• Changes in the skin color of the face;  fast or irregular breathing;  puffiness or swelling of the eyelids or around the eyes;  shortness of breath, troubled breathing, tightness in chest, and/or wheezing;  skin rash, hives, and/or itching 

Also, check with your doctor as soon as possible if any of the following occur:

• Bleeding from gums when brushing teeth;  heavy bleeding or oozing from cuts or wounds;  unexplained bruising or purplish areas on skin;  unexplained nosebleeds ;  unusually heavy or unexpected menstrual bleeding  

Other side effects that may need medical attention may occur while you are using this medicine. Check with your doctor as soon as possible if any of the following side effects occur:

• Less common or rare
  • Back or rib pain (with long-term use only);  change in skin color, especially near the place of injection or in the fingers, toes, arms, or legs;  chest pain;  chills and/or fever;  collection of blood under skin (blood blister) at place of injection;  decrease in height (with long-term use only);  frequent or persistent erection;  irritation, pain, redness, or ulcers at place of injection;  itching and burning feeling, especially on the bottom of the feet;  nausea and/or vomiting;  numbness or tingling in hands or feet;  pain, coldness, or blue color of skin of arms or legs;  peeling of skin;  runny nose;  tearing of eyes;  unusual hair loss (with long-term use only) 
  
  

Other side effects not listed above may also occur in some patients. If you notice any other effects, check with your doctor.