Azathioprine: Uses, Side Effects

Azathioprine weakens your body’s immune system, to help keep it from “rejecting” a transplanted organ such as a kidney. Organ rejection happens when the immune system treats the new organ as an invader and attacks it.

Azathioprine is used to prevent your body from rejecting a transplanted kidney. Azathioprine is also used to treat symptoms of rheumatoid arthritis.

Azathioprine may also be used for purposes not listed in this medication guide.


Important Information

Azathioprine may cause a rare type of lymphoma (cancer) of the liver, spleen, and bone marrow that can be fatal. This has occurred mainly in teenagers and young men with Crohn’s disease or ulcerative colitis.


Before taking this medicine

You should not take azathioprine if you are allergic to azathioprine.

You should not use azathioprine to treat rheumatoid arthritis if you are pregnant. This medicine can harm an unborn baby. Use effective birth control to prevent pregnancy while using this medicine.

Azathioprine may cause a rare type of lymphoma (cancer) of the liver, spleen, and bone marrow that can be fatal. This has occurred mainly in teenagers and young men with Crohn’s disease or ulcerative colitis. However, anyone with an inflammatory autoimmune disorder may have a higher risk of lymphoma. Talk with your doctor about your own risk.

While taking azathioprine, you may have a higher risk of developing skin cancer. Ask your doctor about skin symptoms to watch for.

Tell your doctor if you have ever had:

  • kidney disease, or a kidney transplant (if you are using azathioprine for rheumatoid arthritis);
  • any type of viral, bacterial, or fungal infection;
  • liver disease; or
  • chemotherapy with medications like cyclophosphamide, chlorambucil, melphalan, busulfan, and others.

You should not breast-feed while you are using azathioprine.


Side effects

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Azathioprine may cause a serious brain infection that can lead to disability or death. Call your doctor right away if you have problems with speech, thought, vision, or muscle movement. These symptoms may start gradually and get worse quickly.

Stop using azathioprine and call your doctor right away if you have any of these symptoms of lymphoma:

  • fever, swollen glands, body aches, night sweats, not feeling well;
  • pale skin, rash, easy bruising or bleeding;
  • cold hands and feet, feeling light-headed or short of breath;
  • pain in your upper stomach that may spread to your shoulder; or
  • feeling full after eating only a small amount, weight loss.

Also call your doctor at once if you have:

  • signs of infection (fever, chills, weakness, flu symptoms, sore throat, cough, pain or burning when you urinate);
  • severe nausea, vomiting, or diarrhea;
  • easy bruising, unusual bleeding;
  • rapid heartbeats, shortness of breath;
  • pale skin, cold hands and feet; or
  • dark urine, jaundice (yellowing of the skin or eyes).

Common side effects may include:

  • nausea, diarrhea, stomach pain;
  • hair loss; or
  • skin rash.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects.


What other drugs will affect azathioprine?

Tell your doctor about all your current medicines. Many drugs can affect azathioprine, especially:

  • allopurinol;
  • febuxostat; or
  • ribavirin.

This list is not complete, and many other drugs may affect azathioprine. This includes prescription and over-the-counter medicines, vitamins, and herbal products.


Keyword: azathioprine.

* The Content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.