Azathioprine Oral, Intravenous

ay-za-THYE-oh-preen

Oral routeTablet

Chronic immunosuppression with this purine antimetabolite increases risk of neoplasia in humans. Physicians using this drug should be very familiar with this risk as well as with the mutagenic potential to both men and women and with possible hematologic toxicities .

Chronic immunosuppression with this purine antimetabolite increases risk of neoplasia in humans. Physicians using this drug should be very familiar with this risk as well as with the mutagenic potential to both men and women and with possible hematologic toxicities .

Intravenous routePowder for Solution

Chronic immunosuppression with this purine antimetabolite increases risk of neoplasia in humans. Physicians using this drug should be very familiar with this risk as well as with the mutagenic potential to both men and women and with possible hematologic toxicities .

Chronic immunosuppression with this purine antimetabolite increases risk of neoplasia in humans. Physicians using this drug should be very familiar with this risk as well as with the mutagenic potential to both men and women and with possible hematologic toxicities .

Commonly used brand name(s):

In the U.S.

  • Azasan
  • Imuran

Available Dosage Forms:

  • Tablet
  • Powder for Solution

Therapeutic Class: Antirheumatic, Cytotoxic

Pharmacologic Class: Antimetabolite

Uses For azathioprine

Azathioprine belongs to the group of medicines known as immunosuppressive agents. It is used to reduce the body's natural immunity in patients who receive organ transplants. It is also used to treat rheumatoid arthritis. Azathioprine may also be used for other conditions as determined by your doctor.

Azathioprine is a very strong medicine. You and your doctor should talk about the need for azathioprine and its risks. Even though azathioprine may cause side effects that could be very serious, remember that it may be required to treat your medical problem.

Azathioprine is available only with your doctor's prescription.

Once a medicine has been approved for marketing for a certain use, experience may show that it is also useful for other medical problems. Although these uses are not included in product labeling, azathioprine is used in certain patients with the following medical conditions:

  • Bowel disease, inflammatory
  • Cirrhosis, biliary
  • Dermatomyositis, systemic
  • Glomerulonephritis
  • Hepatitis, chronic active
  • Lupus erythematosus, systemic
  • Myasthenia gravis
  • Myopathy, inflammatory
  • Nephrotic syndrome
  • Pemphigoid
  • Pemphigus

Before Using azathioprine

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 azathioprine, the following should be considered:

Allergies

Tell your doctor if you have ever had any unusual or allergic reaction to azathioprine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.

Pediatric

azathioprine 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.

Geriatric

Many medicines have not been studied specifically in older people. Therefore, it may not be known whether they work exactly the same way they do in younger adults. Although there is no specific information comparing use of azathioprine in the elderly with use in other age groups, azathioprine is not expected to cause different side effects or problems in older people than it does in younger adults.

Pregnancy

Pregnancy CategoryExplanation
All TrimestersDStudies in pregnant women have demonstrated a risk to the fetus. However, the benefits of therapy in a life threatening situation or a serious disease, may outweigh the potential risk.

Breast Feeding

There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.

Interactions with Medicines

Using azathioprine with any of the following medicines is not recommended. Your doctor may decide not to treat you with this medication or change some of the other medicines you take.

  • Febuxostat

Using azathioprine with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

  • Alacepril
  • Alfalfa
  • Allopurinol
  • Bacillus of Calmette and Guerin Vaccine, Live
  • Benazepril
  • Black Cohosh
  • Captopril
  • Cilazapril
  • Enalaprilat
  • Enalapril Maleate
  • Fosinopril
  • Lisinopril
  • Measles Virus Vaccine, Live
  • Mercaptopurine
  • Moexipril
  • Mumps Virus Vaccine, Live
  • Mycophenolic Acid
  • Pentopril
  • Perindopril
  • Poliovirus Vaccine, Live
  • Quinapril
  • Ramipril
  • Ribavirin
  • Rotavirus Vaccine, Live
  • Rubella Virus Vaccine, Live
  • Smallpox Vaccine
  • Spirapril
  • Trandolapril
  • Typhoid Vaccine
  • Varicella Virus Vaccine
  • Yellow Fever Vaccine
  • Zofenopril

Using azathioprine with any of the following medicines may cause an increased risk of certain side effects, but using both drugs may be the best treatment for you. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

  • Cyclosporine
  • Phenprocoumon
  • Warfarin

Interactions with Food/Tobacco/Alcohol

Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.

Other Medical Problems

The presence of other medical problems may affect the use of azathioprine. Make sure you tell your doctor if you have any other medical problems, especially:

  • Chickenpox (including recent exposure) or
  • Herpes zoster (shingles)—Risk of severe disease affecting other parts of the body
  • Gout—Allopurinol (used to treat gout) may increase wanted and unwanted effects of azathioprine
  • Infection—Azathioprine decreases your body's ability to fight infection
  • Kidney disease or
  • Liver disease—Effects of azathioprine may be increased because of slower removal from the body
  • Pancreatitis (inflammation of the pancreas)—Azathioprine can cause pancreatitis

Proper Use of azathioprine

Use azathioprine only as directed by your doctor. Do not use more or less of it, and do not use it more often than your doctor ordered. The exact amount of medicine you need has been carefully worked out. Taking too much may increase the chance of side effects, while taking too little may not properly treat your condition.

azathioprine is sometimes given together with certain other medicines. If you are using a combination of medicines, make sure that you take each one at the proper time and do not mix them up. Ask your health care professional to help you plan a way to remember to take your medicines at the right times.

Do not stop taking azathioprine without first checking with your doctor.

Azathioprine sometimes causes nausea or vomiting. Taking azathioprine after meals or at bedtime may lessen stomach upset. Ask your health care professional for other ways to lessen these effects.

If you vomit shortly after taking a dose of azathioprine, check with your doctor. You will be told whether to take the dose again or to wait until the next scheduled dose.

Dosing

The dose of azathioprine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of azathioprine. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

  • For oral dosage form (tablets):
    • For transplant rejection:
      • Adults, teenagers, and children: Dose is based on body weight or size. The usual beginning dose is 3 to 5 milligrams (mg) per kilogram (kg) (1.5 to 2 mg per pound) of body weight a day. As time goes on, your doctor may lower your dose to 1 to 3 mg per kg (0.5 to 1.5 mg per pound) of body weight a day.
    • For rheumatoid arthritis:
      • Adults, teenagers, and children: Dose is based on body weight or size. The usual beginning dose is 1 mg per kg (0.5 mg per pound) of body weight a day. Your doctor will increase this dose as needed. The highest dose is usually not more than 2.5 mg per kg (1 mg per pound) of body weight a day. Your doctor may then lower your dose as needed.
  • For injection dosage form:
    • For transplant rejection:
      • Adults, teenagers, and children: Dose is based on body weight or size. The usual beginning dose is 3 to 5 milligrams (mg) per kilogram (kg) (1.5 to 2 mg per pound) of body weight a day. As time goes on, your doctor may lower your dose to 1 to 3 mg per kg (0.5 to 1.5 mg per pound) of body weight a day.

Missed Dose

If you miss a dose of azathioprine, skip the missed dose and go back to your regular dosing schedule. Do not double doses.

If you are taking more than one dose a day, take the missed dose as soon as you remember it. If it is time for your next dose, take both doses together, then go back to your regular dosing schedule. If you miss more than one dose, check with your doctor.

Storage

Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing.

Keep out of the reach of children.

Do not keep outdated medicine or medicine no longer needed.

Precautions While Using azathioprine

It is very important that your doctor check your progress at regular visits to make sure that azathioprine is working properly and to check for unwanted effects.

While you are being treated with azathioprine, and after you stop treatment with it, it is important to see your doctor about the immunizations (vaccinations) you should receive. Do not get any immunizations without your doctor's approval. Azathioprine lowers your body's resistance to infections. For some immunizations, there is a chance you might get the infection the immunization is meant to prevent. For other immunizations, it may be especially important to receive the immunization to prevent a disease. In addition, other persons living in your household should not take oral polio vaccine since there is a chance they could pass the polio virus on to you. Also, avoid persons who have recently taken oral polio vaccine. Do not get close to them, and do not stay in the same room with them for very long. If you cannot take these precautions, you should consider wearing a protective face mask that covers the nose and mouth.

Azathioprine can temporarily lower the number of white blood cells in your blood, increasing the chance of getting an infection. It can also lower the number of platelets, which are necessary for proper blood clotting. If this occurs, there are certain precautions you can take, especially when your blood count is low, to reduce the risk of infection or bleeding:

  • If you can, avoid people with infections. Check with your doctor as soon as possible if you think you are getting an infection or if you get a fever or chills, cough or hoarseness, lower back or side pain, or painful or difficult urination.
  • Check with your doctor as soon as possible if you notice any unusual bleeding or bruising; black, tarry stools; blood in urine or stools; or pinpoint red spots on your skin.
  • Be careful when using a regular toothbrush, dental floss, or toothpick. Your medical doctor, dentist, or nurse may recommend other ways to clean your teeth and gums. Check with your health care professional before having any dental work done.
  • Do not touch your eyes or the inside of your nose unless you have just washed your hands and have not touched anything else in the meantime.
  • Be careful not to cut yourself when you are using sharp objects such as a safety razor or fingernail or toenail cutters.
  • Avoid contact sports or other situations where bruising or injury could occur.

The effects of azathioprine may cause increased infections and delayed healing. Dental work, whenever possible, should be completed prior to beginning azathioprine.

azathioprine Side Effects

Along with its needed effects, a medicine may cause some unwanted effects. Some side effects will have signs or symptoms that you can see or feel. Your doctor will watch for others by doing certain tests.

Also, because of the way azathioprine acts on the body, there is a chance that it might cause other unwanted effects that may not occur until months or years after the medicine is used. These delayed effects may include certain types of cancer, such as leukemia, lymphoma, or skin cancer. However, the risk of cancer seems to be lower in people taking azathioprine for arthritis. Discuss these possible effects with your doctor.

Check with your doctor as soon as possible if any of the following side effects occur:

More common
  • Cough or hoarseness
  • fever or chills
  • lower back or side pain
  • painful or difficult urination
  • unusual tiredness or weakness
Less common
  • Black, tarry stools
  • blood in urine or stools
  • pinpoint red spots on skin
  • unusual bleeding or bruising
Rare
  • Fast heartbeat
  • fever (sudden)
  • muscle or joint pain
  • nausea, vomiting, and diarrhea (severe)
  • redness or blisters on skin
  • shortness of breath
  • sores in mouth and on lips
  • stomach pain
  • swelling of feet or lower legs
  • unusual feeling of discomfort or illness (sudden)

azathioprine may also cause the following side effect that your doctor will watch for:

Less common
  • Liver problems

For patients taking azathioprine for rheumatoid arthritis:

Signs and symptoms of blood problems (black, tarry stools; blood in urine or stools; cough or hoarseness; fever or chills; lower back or side pain; painful or difficult urination; pinpoint red spots on skin; unusual tiredness or weakness; or unusual bleeding or bruising) are less likely to occur in patients taking azathioprine for rheumatoid arthritis than in patients taking azathioprine for transplant rejection. This is because lower doses are often used.

Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common
  • Loss of appetite
  • nausea or vomiting
Less common
  • Skin rash

After you stop using azathioprine, it may still produce some side effects that need attention. During this period of time, check with your doctor immediately if you notice the following side effects:

  • Black, tarry stools
  • blood in urine
  • cough or hoarseness
  • fever or chills
  • lower back or side pain
  • painful or difficult urination
  • pinpoint red spots on skin
  • unusual bleeding or bruising

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

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

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