AZATHIOPRINE (Systemic)
Some commonly used brand names are:
In the U.S.?
In Canada?
Generic name product may be available in the U.S.
Category
- Immunosuppressant
- antirheumatic (disease-modifying)
- bowel disease(inflammatory) suppressant
- lupus erythematosussuppressant
Description
Azathioprine (ay-za-THYE-oh-preen)belongs to the group of medicines known as immunosuppressive agents. It isused 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 usedfor other conditions as determined by your doctor.
Azathioprine is a very strong medicine. You and your doctor should talkabout the need for this medicine and its risks. Even though azathioprine maycause side effects that could be very serious, remember that it may be requiredto treat your medical problem.
Azathioprine is available only with your doctor's prescription, in thefollowing dosage forms:
Oral- Tablets (U.S. and Canada)
Parenteral- Injection (U.S. and Canada)
Before Using This Medicine
In deciding to use a medicine,the risks of taking the medicine must be weighed against the good it willdo. This is a decision you and your doctor will make. For azathioprine, thefollowing should be considered:
Allergies?Tell your doctor if you have ever had any unusual orallergic reaction to azathioprine. Also tell your health care professionalif you are allergic to any other substances, such as foods, preservatives,or dyes.
Pregnancy?Use of azathioprine is not recommended during pregnancy.It may cause birth defects if either the male or the female is using it atthe time of conception. The use of birth control methods is recommended. Ifyou have any questions about this, check with your doctor.
Breast-feeding?Azathioprine passes into breast milk. Because thismedicine may cause serious side effects, breast-feeding is generally not recommendedwhile you are using it.
Children?This medicine has been tested in children and, ineffective doses, has not been shown to cause different side effects or problemsthan it does in adults.
Older adults?Many medicines have not been studied specificallyin older people. Therefore, it may not be known whether they work exactlythe same way they do in younger adults. Although there is no specific informationcomparing use of azathioprine in the elderly with use in other age groups,this medicine is not expected to cause different side effects or problemsin older people than it does in younger adults.
Other medicines?Although certain medicines should not be usedtogether at all, in other cases two different medicines may be used togethereven if an interaction might occur. In these cases, your doctor may want tochange the dose, or other precautions may be necessary. When you are takingor receiving azathioprine it is especially important that your health careprofessional know if you are taking any of the following:
- Allopurinol (e.g., Zyloprim)?May interfere with removal ofazathioprine from the body; effects of azathioprine (including toxicity) maybe increased
- Chlorambucil (e.g., Leukeran) or
- Corticosteroids (cortisone-like medicine) or
- Cyclophosphamide (e.g., Cytoxan) or
- Cyclosporine (e.g., Sandimmune) or
- Mercaptopurine (e.g., Purinethol) or
- Muromonab-CD3 (monoclonal antibody) (e.g., Orthoclone OKT3)?Theremay be an increased risk of infection and cancer because azathioprine reducesthe body's ability to fight them
Other medical problems?The presence of other medicalproblems may affect the use of azathioprine. Make sure you tell your doctorif you have any other medical problems, especially:
- Chickenpox (including recent exposure) or
- Herpes zoster (shingles)?Risk of severe disease affecting otherparts of the body
- Gout?Allopurinol (used to treat gout) may increase wanted andunwanted effects of azathioprine
- Infection?Azathioprine decreases your body's ability to fightinfection
- Kidney disease or
- Liver disease?Effects of azathioprine may be increased becauseof slower removal from the body
- Pancreatitis (inflammation of the pancreas)?Azathioprine cancause pancreatitis
Proper Use of This Medicine
Use this medicine only as directed by your doctor. Do not use moreor less of it, and do not use it more often than your doctor ordered. Theexact amount of medicine you need has been carefully worked out. Taking toomuch may increase the chance of side effects, while taking too little maynot properly treat your condition.
This medicine is sometimes given together with certain other medicines.If you are using a combination of medicines, make sure that you take eachone at the proper time and do not mix them up. Ask your health care professionalto help you plan a way to remember to take your medicines at the right times.
Do not stop taking this medicine without first checkingwith your doctor.
Azathioprine sometimes causes nausea or vomiting. Taking this medicineafter meals or at bedtime may lessen stomach upset. Ask your health care professionalfor other ways to lessen these effects.
If you vomit shortly after taking a dose of azathioprine, check with yourdoctor. You will be told whether to take the dose again or to wait until thenext scheduled dose.
Dosing?The dose of azathioprine will be differentfor different patients. Follow your doctor's orders or the directions on thelabel. The following information includes only the average doses of azathioprine. If your dose is different, do not change it unlessyour doctor tells you to do so.
The number of doses you take each day, the time allowedbetween doses, and the length of time you take the medicine depend on themedical problem for which you are taking azathioprine.
- For oral dosage form (tablets):
- For transplant rejection:
- Adults, teenagers, and children: Dose is based on body weight orsize. 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 doctormay lower your dose to 1 to 3 mg per kg (0.5 to 1.5 mg per pound) of bodyweight a day.
- For rheumatoid arthritis:
- Adults, teenagers, and children: Dose is based on body weight orsize. The usual beginning dose is 1 mg per kg (0.5 mg per pound) of body weighta day. Your doctor will increase this dose as needed. The highest dose isusually 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 orsize. 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 doctormay lower your dose to 1 to 3 mg per kg (0.5 to 1.5 mg per pound) of bodyweight a day.
Missed dose?If you miss a dose of this medicine and your dosingschedule is:
- One dose a day?Do not take the missed dose at all and do notdouble the next one. Instead, go back to your regular dosing schedule andcheck with your doctor.
- More than one dose a day?Take the missed dose as soon as youremember it. If it is time for your next dose, take both doses together, thengo back to your regular dosing schedule. If you miss more than one dose, checkwith your doctor.
Storage?To store this medicine:
- Keep out of the reach of children.
- Store away from heat and direct light.
- Do not store in the bathroom, near the kitchen sink, or in otherdamp places. Heat or moisture may cause the medicine to break down.
- Do not keep outdated medicine or medicine no longer needed. Be surethat any discarded medicine is out of the reach of children.
Precautions While Using This Medicine
It is very important that your doctor check your progress atregular visits to make sure that this medicine is working properlyand to check for unwanted effects.
While you are being treated with azathioprine, and after you stop treatmentwith it, it is important to see your doctor about theimmunizations (vaccinations) you should receive. Do not get any immunizationswithout your doctor's approval. Azathioprine lowers your body's resistanceto infections. For some immunizations, there is a chance you might get theinfection the immunization is meant to prevent. For other immunizations, itmay be especially important to receive the immunization to prevent a disease.In addition, other persons living in your household should not take oral poliovaccine 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 getclose to them, and do not stay in the same room with them for very long. Ifyou cannot take these precautions, you should consider wearing a protectiveface mask that covers the nose and mouth.
Azathioprine can temporarily lower the number of white blood cells in yourblood, increasing the chance of getting an infection. It can also lower thenumber of platelets, which are necessary for proper blood clotting. If thisoccurs, there are certain precautions you can take, especially when your bloodcount is low, to reduce the risk of infection or bleeding:
- If you can, avoid people with infections. Check with your doctoras soon as possible if you think you are getting an infection or if you geta fever or chills, cough or hoarseness, lower back or side pain, or painfulor difficult urination.
- Check with your doctor as soon as possible if you notice any unusualbleeding or bruising; black, tarry stools; blood in urine or stools; or pinpointred 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 yourteeth and gums. Check with your health care professional before having anydental work done.
- Do not touch your eyes or the inside of your nose unless you havejust washed your hands and have not touched anything else in the meantime.
- Be careful not to cut yourself when you are using sharp objects suchas a safety razor or fingernail or toenail cutters.
- Avoid contact sports or other situations where bruising or injurycould occur.
The effects of azathioprine may cause increased infections and delayedhealing. Dental work, whenever possible, should be completed prior to beginningthis medicine.
Side Effects of This Medicine
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. Yourdoctor will watch for others by doing certain tests.
Also, because of the way this medicine actson the body, there is a chance that it might cause other unwanted effectsthat may not occur until months or years after the medicine is used. Thesedelayed 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 takingazathioprine for arthritis. Discuss these possible effects with your doctor.
Other sideeffects may occur that usually do not need medical attention. These side effectsmay go away during treatment as your body adjusts to the medicine. However,check with your doctor if any of the following side effects continue or arebothersome:
After you stop using this medicine, it may still produce someside effects that need attention. During this period of time check with yourdoctor as soon as possible if you notice any of the following:
Black, tarry stools; blood in urine; cough or hoarseness; fever or chills; lower back or side pain; painful or difficult urination; pinpointred spots on skin; unusual bleeding or bruising
Other side effects not listed above may also occur insome patients. If you notice any other effects, check with your doctor.
Additional Information
Once a medicine has been approvedfor marketing for a certain use, experience may show that it is also usefulfor other medical problems. Although these uses are not included in productlabeling, azathioprine is used in certain patients with the following medicalconditions:
- Bowel disease, inflammatory
- Cirrhosis, biliary
- Dermatomyositis, systemic
- Glomerulonephritis
- Hepatitis, chronic active
- Lupus erythematosus, systemic
- Myasthenia gravis
- Myopathy, inflammatory
- Nephrotic syndrome
- Pemphigoid
- Pemphigus
Other than the above information, there is no additional information relatingto proper use, precautions, or side effects for these uses.
Revised: 12/03/1998
