Leukeran

Definition

Immunosuppressant drugs are medicines that reduce the body's natural defenses against foreign invaders or materials. Used in transplant patients, these drugs help prevent their bodies from rejecting transplanted organs.

Purpose

When an organ, such as a liver, a heart or a kidney, is transplanted from one person (the donor) into another (the recipient), the recipient's immune system has the same response it has to any foreign material. It attacks and tries to destroy the organ. Immunosuppressant drugs help prevent this from happening by subduing the natural immune response. The problem is that the drugs' action also makes the body more vulnerable to infection. For that reason, people who take this medicine need to be especially careful to avoid infections.

In addition to being used to prevent organ rejection, immunosuppressant drugs sometimes are used to treat severe skin disorders such as psoriasis and other diseases such as rheumatoid arthritis, Crohn's disease (chronic inflammation of the digestive tract) and patchy hair loss (alopecia areata).

Description

Immunosuppressant drugs are available only with a physician's prescription and come in tablet, capsule, liquid and injectable forms. Commonly used immunosuppressant drugs include azathioprine (Imuran), cyclosporine (Sandimmune) and tacrolimus (Prograf).

Recommended dosage

The recommended dosage depends on the type and form of immunosuppressant drug and the purpose for which it is being used. Doses may be different for different patients. Check with the physician who prescribed the drug or the pharmacist who filled the prescription for the correct dosage.

Taking this medicine exactly as directed is very important. Never take smaller, larger or more frequent doses, and do not take the drug for longer than directed. The physician will decide exactly how much of the medicine each patient needs. Taking too much may increase the risk of side effects, while taking too little may not do any good. Blood tests often are necessary to make sure that the right amount of the medicine is getting into the body.

Immunosuppressant drugs sometimes are given along with other medicines. Be sure to follow the directions for taking each medicine. If trying to remember when to take each medicine is confusing, ask a health care professional for tips on how to keep them straight.

Do not stop taking an immunosuppressant drug without checking with the physician who prescribed it.

Precautions

Seeing a physician regularly while taking immunosuppressant drugs is important. These regular check-ups will allow the physician to make sure the medicine is working as it should and to watch for unwanted effects. These medicines are very powerful and can cause serious side effects, such as high blood pressure, kidney problems and liver problems. Some side effects may not show up until years after the medicine is used. However, the good these drugs can do may outweigh the possible harm. Anyone who has been advised to take immunosuppressant drugs should thoroughly discuss the risks and benefits with his or her physician

Immunosuppressant drugs lower a person's resistance to infection and can make infections harder to treat. The drugs can also increase the chance of uncontrolled bleeding. Anyone who has a serious infection or injury while taking immunosuppressant drugs should get prompt medical attention and should make sure that the physician in charge knows about the medicine. Check with a physician immediately if signs of infection, such as fever or chills, cough or hoarseness, pain in the lower back or side, or painful or difficult urination, occur. Let the physician know about unusual bruising or bleeding; blood in the urine; bloody or black, tarry stools; or tiny red spots on the skin. Other ways of preventing infection and injury include washing the hands frequently, avoiding sports where injuries may occur, and being careful when using knives, razors, fingernail clippers or other sharp objects. Avoiding contact with people who have infections is also important. In addition, people who are taking or have been taking immunosuppressant drugs should not have immunizations, such as smallpox vaccinations, without checking with their physicians. Because of their low resistance to infection, people taking these drugs might get the disease that the vaccine is designed to prevent. People taking immunosuppressant drugs also should avoid contact with anyone who has taken the oral polio vaccine, as there is a chance the virus could be passed on to them. Other people living in their home should not take the oral polio vaccine.

Immunosuppressant drugs may cause the gums to become tender and swollen or to bleed. If this happens, check with a physician or dentist right away. Regular brushing, flossing, cleaning and gum massage may help prevent this problem. Ask the dentist for advice on how to clean the teeth and mouth without causing injury.

Special conditions

People who have certain medical conditions or who are taking certain other medicines may have problems if they take immunosuppressant drugs. Before taking these drugs, be sure to let the physician know about any of these conditions:

Anyone who has had unusual reactions to immunosuppressant drugs in the past should let his or her physician know before taking the drugs again. The physician should also be told about any allergies to foods, dyes, preservatives, or other substances.

Azathioprine may cause birth defects if used during pregnancy, or if either the male or female is using it when conception occurs. Anyone taking this medicine should use a barrier method of birth control, such as a diaphragm or condoms. Birth control pills should not be used without a physician's approval. Women who become pregnant while taking this medicine should check with their physicians immediately.

The medicine's effects have not been studied in humans during pregnancy. Women who are pregnant or who may become pregnant and who need to take this medicine should check with their physicians.

Breastfeeding

Immunosuppressant drugs pass into breast milk and may cause problems in nursing babies whose mothers take it. Breastfeeding is not recommended for women taking this medicine.

People who have certain medical conditions may have problems if they take immunosuppressant drugs. For example:

• People who have shingles (herpes zoster) or chickenpox or who have recently been exposed to chickenpox may develop severe disease in other parts of their bodies when they take this medicine.
• The medicine's effects may be greater in people with kidney disease or liver disease, because their bodies are slow to get rid of the medicine.
• The effects of oral forms of this medicine may be less in people with intestinal problems, because the medicine cannot be absorbed into the body.

Before using immunosuppressant drugs, people with these or other medical problems should make sure their physicians are aware of their conditions.

Taking immunosuppressant drugs with certain other drugs may affect the way the drugs work or may increase the chance of side effects.

Side effects

People who take immunosuppressant drugs may be at higher than normal risk of developing certain kinds of cancers later in life. However, the drugs may be necessary to prevent the failure of a life-saving transplant. The possible harm must be carefully weighed against the drugs' benefits. Discussing the medicine's good and bad points with a physician will help a patient decide about whether to take immunosuppressant drugs.

Some side effects of immunosuppressant drugs are minor and usually go away as the body adjusts to the medicine. These include loss of appetite, nausea or vomiting, increased hair growth, and trembling or shaking of the hands. Medical attention is not necessary unless these side effects continue or cause problems.

Check with a physician immediately if any of these side effects occur:

• Unusual tiredness or weakness
• Fever or chills
• Frequent need to urinate.

Interactions

Immunosuppressant drugs may interact with other medicines. When this happens, the effects of one or both drugs may change or the risk of side effects may be greater. For example:

• The effects of azathioprine may be greater in people who take allopurinol, a medicine used to treat gout.
• A number of medicines, including female hormones (estrogens), male hormones (androgens), the antifungal drug ketoconazole (Nizoral), the ulcer drug cimetidine (Tagamet) and the erythromycins (used to treat infections), may increase the effects of cyclosporine.
• The risk of cancer or infection may be greater when immunosuppressant drugs are combined with certain other drugs which also lower the body's ability to fight disease and infection. These drugs include corticosteroids such as prednisone; the anticancer drugs chlorambucil (Leukeran), cyclophosphamide (Cytoxan) and mercaptopurine (Purinethol); and the monoclonal antibody muromonab-CD3 (Orthoclone), which also is used to prevent transplanted organ rejection.

Not every drug that may interact with immunosuppressant drugs is listed here. Anyone who takes immunosuppressant drugs should let the physician know all other medicines he or she is taking and should ask whether the possible interactions can interfere with treatment.

Key Terms

Chronic

A word used to describe a long-lasting condition. Chronic conditions often develop gradually and involve slow changes.

Conception

The union of egg and sperm.

Fetus

A developing baby inside the womb.

Immune system

The body's natural defenses against disease and infection.

Inflammation

Pain, redness, swelling, and heat that usually develop in response to injury or illness.

Psoriasis

A skin disease in which people have itchy, scaly, red patches on the skin.

Further Reading

Gale Encyclopedia of Medicine. Gale Research, 1999.