Azathioprine

What is azathioprine?

Azathioprine belongs to the group of medicines known as immunosuppressants. It is used to reduce the body's natural immunity. This helps the body to accept a transplanted organ and it also decreases the body's harmful response to diseases affecting the immune system (such as rheumatoid arthritis or inflammatory bowel disease).

You may hear azathioprine called by its brand name, Imuran. Azathioprine comes as a tablet and an injection, and certain pharmacies also make a liquid form.

Before giving azathioprine to your child?

Tell your child's doctor if your child is allergic to azathioprine, other medicines, preservatives, dyes, or food.

Talk with your child's doctor or pharmacist if your child has any of the following conditions. Precautions may need to be taken with this medicine if your child has:

• Kidney or liver disease.
• An infection (as azathioprine may decrease your child's ability to fight infection)

How should you give your child azathioprine?

• Exactly as your doctor or your pharmacist tells you to, even if your child seems better.
• Talk to your child's doctor before you change the dose or stop giving this medicine for any reason. Your child may become ill if they stop taking this medicine suddenly.
• At the same time every day. Pick a time that is easy for you so that you do not miss doses.
• With or without food, however if the medicine upsets your child's stomach give after a meal.
• If your child is taking the liquid form, shake the bottle well. Measure the dose with the special spoon or syringe that the pharmacist gave you.
• If your child throws up (vomits) shortly after taking the medicine, check with your nurse or doctor about whether to give another dose.

Azathioprine lowers your child's immune response, which increases your child's chances of getting an infection. Your child can take the following precautions to prevent infections:

• Avoid people with infections, such as a cold or the flu.
• Your child's nurse will review with you what to do in case of fever.

What should you do if your child misses a dose of azathioprine?

• Give the missed dose as soon as you remember.
• If it is almost time for the next dose, skip the missed dose. Give the next dose at the regular time.
• Do not give your child two doses to make up for one missed dose.

How long does azathioprine take to work?

Azathioprine may take up to several months to have its full effect in some conditions.

What are the possible side effects of azathioprine?

Your child may have some of these side effects while they take azathioprine. Check with your child's doctor if your child continues to have any of these side effects, and they do not go away, or they bother your child:

• Loss of appetite
• Upset stomach, throwing up

Most of the following side effects are not common, but they may be a sign of a serious problem. Call your child's doctor right away or take your child to the nearest Emergency Department if your child has any of these side effects:

• If your child shows signs of a life-threatening reaction including: wheezing; chest tightness; fever; itching; bad cough; blue skin colour; swelling of face, lips, tongue, or throat.
• If your child shows any signs or symptoms of infection. These include a fever of 38°C or higher, chills, severe sore throat, ear or sinus pain, cough, increased mucus or change in color, painful urination, mouth sores or a wound that will not heal.
• Severe dizziness or fainting.
• Severe belly pain.
• Severe nausea or vomiting.
• Unusual bruising or bleeding.
• Dark urine or yellow skin or eyes.

Long-term use of azathioprine may very rarely increase the risk of certain types of cancer, including skin cancer and lymphoma. Limit sun exposure and use sunscreen to reduce the risk of skin cancer. Signs and symptoms of lymphoma to look out for include a painless swelling in one or more of the lymph nodes of the neck, collarbone region, armpits, or groin.

What safety measures should you take when your child is using azathioprine?

There are some medicines that should not be taken together with azathioprine or in some cases the dose of azathioprine or the other medicine may need to be adjusted. It is important that you tell your doctor and pharmacist if your child takes any other medications (prescription, over the counter or herbal) including:

• Allopurinol
• Co-trimoxazole (Septra) or trimethoprim
• Aspirin containing products
• Non-steroidal anti-inflammatory drugs (NSAIDs) (e.g. ibuprofen, naproxen)
• Blood thinners (warfarin or clopidogrel)
• Garlic, ginseng, ginkgo, or vitamin E

Be careful about vaccinations while your child is receiving this medicine. While your child is being treated with azathioprine, and for several weeks/months after you stop treatment with it, it is important to see your child's doctor about any immunizations (vaccinations) they may need. Do not get any immunizations without your doctor's approval. Some vaccinations must not be given while your child is taking azathioprine. In addition, other people living in the same house should not take oral polio vaccine since there is a chance they could pass the polio virus on to your child.

There is a chance that azathioprine may cause birth defects if it is taken at the time of conception or if it is taken during pregnancy. If your child is sexually active it is recommended that they use some kind of birth control while receiving azathioprine. Tell your doctor right away if you think your child may be pregnant.

What other important information should you know about azathioprine?

• Keep a list of all medications your child is on and show the list to the doctor or pharmacist.
• Do not share your child’s medicine with others and do not give anyone else’s medicine to your child.
• Make sure you always have enough azathioprine to last through weekends, holidays, and vacations. Call your pharmacy at least 2 days before your child runs out of medicine to order refills.
• If your child needs azathioprine liquid, it must be made by a pharmacy. Check if your pharmacy is able to make azathioprine liquid and ensure that you give them plenty of notice as it may take several days.
• Keep azathioprine at room temperature in a cool, dry place away from sunlight. Do NOT store it in the bathroom or kitchen.
• Do not keep any medicines that are out of date. Check with your pharmacist about the best way to throw away outdated or leftover medicines.
  

Keep azathioprine out of your child’s sight and reach and locked up in a safe place. If your child takes too much azathioprine, call your local Poison Information Centre at one of these numbers. These calls are free. 

• Call 1-844 POISON-X, or 1-844-764-7669, from anywhere in Canada except Quebec.
• Call 1-800-463-5060 if you live in Quebec.