How does this medication work? What will it do for me?
Azathioprine belongs to the group of medications known as immunosuppressive agents. It is used to prevent the rejection of kidney transplants and to treat severe rheumatoid arthritis that is not responding to conventional treatment. Azathioprine prevents rejection of kidney transplant and reduces the inflammation and pain in rheumatoid arthritis by suppressing the body's natural defense, or immune system.
Your doctor may have suggested this medication for conditions other than the ones listed in these drug information articles. As well, some forms of this medication may not be used for all of the conditions discussed here. If you have not discussed this with your doctor or are not sure why you are taking this medication, speak to your doctor. Do not stop taking this medication without consulting your doctor.
Do not give this medication to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take this medication if their doctor has not prescribed it.
What form(s) does this medication come in?
50 mg tablet
Each pale yellow, peanut-shaped tablet, engraved "AZ 50" on one side and score lines on the other, contains azathioprine 50 mg. Nonmedicinal ingredients: lactose, magnesium stearate, microcrystalline cellulose, and starch.
Each 17 mL vial contains azathioprine 50 mg sodium salt. Nonmedicinal ingredient: sodium hydroxide to adjust pH.
How should I use this medication?
Azathioprine is available in tablet and injectable form.
When used to prevent kidney transplant rejection, azathioprine is usually started on the day of transplant with an intravenous (into the vein) injection. The initial dose is based on body weight at 3 to 5 mg per kilogram of body weight daily. After the transplant, tablets are used. The dose is then generally reduced to a maintenance dose of 1 mg to 3 mg per kilogram of body weight per day.
For treatment of rheumatoid arthritis, azathioprine is usually given at a dose of approximately 1 mg per kilogram of body weight (50 mg to 100 mg) per day by mouth, in a single daily dose or on a twice-daily schedule. After 6 to 8 weeks, your doctor may increase your dose by 0.5 mg per kilogram daily if needed. Additional increases may be prescribed by your doctor every 4 weeks up to the maximum daily dose of 2.5 mg per kilogram per day.
Many things can affect the dose of medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones listed here, do not change the way that you are taking the medication without consulting your doctor.
It is important to take this medication exactly as prescribed by your doctor. If you miss a dose and you are taking the pills once a day, do not take the missed dose at all, but go back to your regular dosing schedule. If you are taking pills more than once a day, skip the missed dose and go back to your regular schedule. Do not take a double dose to make up for a missed one. If you are not sure what to do after missing a dose, contact your doctor or pharmacist for advice.
Store this medication at room temperature, protect it from light, and keep it out of the reach of children.
This medication is available under multiple brand names and/or in several different forms. Any specific brand name of this medication may not be available in all of the forms listed here. The forms available for the specific brand you have searched are listed under "What form(s) does this medication come in?"
Do not dispose of medications in wastewater (e.g. down the sink or in the toilet) or in household garbage. Ask your pharmacist how to dispose of medications that are no longer needed or have expired.
Who should NOT take this medication?
Do not use azathioprine if you are allergic to azathioprine or any ingredients of the medication.
What side effects are possible with this medication?
Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent.
The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.
The following side effects have been reported by at least 1% of people taking this medication. Many of these side effects can be managed, and some may go away on their own over time.
Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.
- hair loss
Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not seek medical attention.
Check with your doctor as soon as possible if any of the following side effects occur:
- black, tarry stools or blood in urine or stools
- cough or hoarseness
- fever or chills
- nausea and vomiting
- new marks or change in marks on your skin
- painful or difficult urination
- pinpoint red spots on skin
- unusual bleeding or bruising
- sudden unusual feeling of discomfort or illness
Stop taking the medication and seek immediate medical attention if any of the following occur:
- muscle or bone pain
- severe skin reaction such as redness or blisters on skin or peeling skin
- severe nausea, vomiting, diarrhea, or stomach pain
- dizziness or faintness especially when you stand up
- signs of a severe allergic reaction, e.g.:
- difficulty breathing
- swelling of the face, mouth, throat or tongue
Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.
Are there any other precautions or warnings for this medication?
Before you begin taking a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.
HEALTH CANADA ADVISORY
March 27, 2014
Health Canada has issued new restrictions concerning the use of Imuran (azathioprine). To read the full Health Canada Advisory, visit Health Canada's web site at www.hc-sc.gc.ca.
Cancer: This medication may increase your risk of developing certain types of cancer such as lymphoma (cancer of the immune cells) and skin cancer. Limit your exposure to sunlight and ultraviolet light, wear protective clothing and use sunscreen with a high protection factor.
Bleeding: This medication can decrease the number of platelets (component of the blood that helps blood to clot). Your doctor will monitor your platelet levels regularly while you are taking this medication. If you notice any unusual signs of bruising or bleeding (e.g., bleeding gums, blood in urine, dark-tarry stools), contact your doctor immediately or get immediate medical attention.
Infection: This medication reduces the number of white blood cells that fight infection in the body and can increase the risk of bacterial, fungal, and viral infections. If you notice any signs of infection (e.g., fever, chills, cough, painful urination) or any other unusual symptoms, contact your doctor. Contact your doctor immediately if you come into contact with someone who has chickenpox or shingles. Your doctor will monitor your white blood cell levels regularly while you are taking this medication.
Kidney function: Azathioprine may be cleared from the body more slowly in people with reduced kidney function. If you have reduced kidney function discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.
Liver disease: Azathioprine may be cleared from the body more slowly in people with liver disease. If you have liver disease discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.
This medication may also cause liver problems. Your doctor will monitor for this with blood tests that assess liver function.
Pregnancy: Azathioprine can cause harm to the baby when taken by pregnant women. This medication should not be used during pregnancy unless the benefits outweigh the risks. Effective birth control should be practiced while using this medication. If you become pregnant while you are taking this medication, contact your doctor at once.
Breast-feeding: This medication may pass into breast milk. If you are a breast-feeding mother and are taking azathioprine it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.
Children: The safety and effectiveness of using this medication have not been established for children.
Seniors: The safety and effectiveness of using this medication have not been established for people over the age of 65. Discuss the risks and benefits of taking azathioprine with your doctor.
What other drugs could interact with this medication?
There may be an interaction between azathioprine and any of the following:
If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:
- stop taking one of the medications,
- change one of the medications to another,
- change how you are taking one or both of the medications, or
- leave everything as is.
An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.
Medications other than those listed above may interact with this medication. Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.