Who should not use azathioprine?

Allergies to Ingredients. People who are allergic to any of the following should not use azathioprine.

Azasan

Azathioprine

Imuran

Any of the ingredients in the specific product dispensed

Your pharmacist can tell you all of the ingredients in the specific azathioprine products they stock.

Certain People With Rheumatoid Arthritis. People with rheumatoid arthritis should not use azathioprine if they are pregnant. See the Pregnancy section for more details. People with rheumatoid arthritis who have used certain medicines known as alkylating agents should not use azathioprine. People who have used alkylating agents, such as cyclophosphamide, chlorambucil, and melphalan, may have a higher risk of cancer. 

Do not use azathioprine unless it has been prescribed to you by a health care provider. Use it as prescribed.

Do not share azathioprine with other people, even if they have the same condition as you. It may harm them.

Keep azathioprine out of the reach of children.

Keep all appointments for blood tests after starting azathioprine.

Tell your health care provider about all of your health conditions and any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. This will help them know if azathioprine is right for you.

In particular, make sure that you discuss any of the following.

Vaccines. Talk with your health care provider about any vaccines that you may need. You should not receive certain vaccines right before or while using azathioprine. Tell your health care provider about any vaccines you have recently received or have scheduled.

Other Medicines and Supplements. Azathioprine may interact with other medicines and supplements. Before starting azathioprine, tell your health care provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. See the Interactions section for more details.

Enzyme Deficiency. Tell your health care provider if you have an enzyme deficiency called thiopurine S-methyltransferase (TPMT) or nucleotide diphosphatase (NUDT15) deficiency. When someone has a deficiency, or lack, of these enzymes, their body may not process azathioprine properly, leading to a higher risk of serious side effects.

Other Current and Past Health Conditions. Tell your health care provider if you have any of the following.

Pregnancy. Azathioprine may cause harm to an unborn baby and is not to be used for rheumatoid arthritis if you are pregnant. If you can become pregnant, talk to your health care provider about birth control options that may be right for you. Tell your health care provider right away if you are pregnant or plan to become pregnant. If you are using azathioprine to prevent organ rejection, your health care provider will let you know if you should use azathioprine while you are pregnant or trying to get pregnant.

Breastfeeding. Azathioprine passes into breast milk. Tell your health care provider if you are breastfeeding or plan to breastfeed. Your health care provider will let you know if you should stop breastfeeding or stop azathioprine.