What is azathioprine?

Azathioprine lowers your body’s immune system. The immune system helps your body fight infections. The immune system can also fight or "reject” a transplanted organ such as a liver or kidney. This is because the immune system treats the new organ as an invader.

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

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

Precautions

Do not take this medication if you are allergic to azathioprine.

Taking azathioprine may increase your risk of developing cancer. Talk with your doctor about your specific risk.

Before taking azathioprine, tell your doctor if you are allergic to any drugs, or if you have:

  • liver disease;
  • any type of viral, bacterial, or fungal infection; or
  • if you have recently received chemotherapy treatments with medications such as cyclophosphamide (Cytoxan), chlorambucil (Leukeran), melphalan (Alkeran).

If you have any of these conditions, you may need a dose adjustment or special tests to safely take this medication.

FDA pregnancy category D. This medication can cause harm to an unborn baby. Do not use azathioprine without telling your doctor if you are pregnant. It could harm the unborn baby. Use effective birth control, and tell your doctor if you become pregnant during treatment.

This medication can affect fertility (your ability to have children), whether you are a man or a woman. Talk with your doctor if you have concerns about this.

Azathioprine can pass into breast milk and may harm a nursing baby. Do not use this medication without telling your doctor if you are breast-feeding a baby.

Avoid being near people who have colds, the flu, or other contagious illnesses. Contact your doctor at once if you develop signs of infection.

Do not receive a "live” vaccine while you are being treated with azathioprine and avoid coming into contact with anyone who has recently received a live vaccine. There is a chance that the virus could be passed on to you.

Back to top

Instructions

Seek emergency medical attention if you think you have used too much of this medicine.

Overdose symptoms may include nausea, vomiting, stomach pain, diarrhea, bleeding, fever, chills, and other signs of infection.

If you take this medicine once daily and you miss a dose, take the medicine as soon as you remember. If it is almost time for the next dose, skip the missed dose and wait until your next regularly scheduled time to take the medication. Do not use extra medicine to make up the missed dose.

If you take this medicine more than once daily and you miss a dose, take the medicine as soon as you remember. If it is almost time for the next dose, take both doses together, then go back to your regular dosing schedule.

Call your doctor if you have missed more than one dose.

Back to top

Side Effects

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

Call your doctor at once if you have a serious side effect such as:

  • pale skin, easy bruising or bleeding, unusual weakness;
  • fever, chills, sore throat, body aches, weakness, muscle pain, flu symptoms;
  • severe nausea, vomiting, or diarrhea;
  • severe pain in your upper stomach spreading to your back, fast heart rate;
  • pain or burning with urination;
  • stomach pain, loss of appetite, dark urine, clay-colored stools, and jaundice (yellowing of the skin or eyes); or
  • white patches or sores inside your mouth or on your lips.

Less serious side effects may include:

  • mild upset stomach, nausea, diarrhea, loss of appetite;
  • hair loss; or
  • skin rash.

This is not a complete list of side effects and others may occur. Tell your doctor about any unusual or bothersome side effect. You may report side effects to FDA at 1-800-FDA-1088.

Back to top

Interactions

Before taking azathioprine, tell your doctor if you are taking, have taken, or need to take any of the following medicines:

  • allopurinol (Zyloprim);
  • mercaptopurine (Purinethol);
  • methotrexate (Rheumatrex, Immunex);
  • a blood thinner such as warfarin (Coumadin);
  • cyclosporine (Neoral, Sandimmune);
  • olsalazine (Dipentum), or sulfasalazine (Azulfidine);
  • sulfamethoxasole and trimethoprim (Trimpex, Proloprim, Bactrim, Septra, others); or
  • an ACE inhibitor such as benazepril (Lotensin), captopril (Capoten), fosinopril (Monopril), enalapril (Vasotec), lisinopril (Prinivil, Zestril), moexipril (Univasc), perindopril (Aceon), quinapril (Accupril), ramipril (Altace), or trandolapril (Mavik).

This list is not complete and there may be other drugs that can interact with azathioprine. Tell your doctor about all the prescription and over-the-counter medications you use. This includes vitamins, minerals, herbal products, and drugs prescribed by other doctors. Do not start using a new medication without telling your doctor.

Other Names

Azasan, Imuran, and azathioprine

Back to top

Disclaimer

Every effort has been made to ensure that the information provided by Cerner Multum, Inc. ('Multum') is accurate, up-to-date, and complete, but no guarantee is made to that effect. Drug information contained herein may be time sensitive. Multum information has been compiled for use by healthcare practitioners and consumers in the United States and therefore Multum does not warrant that uses outside of the United States are appropriate, unless specifically indicated otherwise. Multum's drug information does not endorse drugs, diagnose patients or recommend therapy. Multum's drug information is an informational resource designed to assist licensed healthcare practitioners in caring for their patients and/or to serve consumers viewing this service as a supplement to, and not a substitute for, the expertise, skill, knowledge and judgment of healthcare practitioners. The absence of a warning for a given drug or drug combination in no way should be construed to indicate that the drug or drug combination is safe, effective or appropriate for any given patient. Multum does not assume any responsibility for any aspect of healthcare administered with the aid of information Multum provides. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the drugs you are taking, check with your doctor, nurse or pharmacist.

Copyright 1996-2004 Cerner Multum, Inc. Version 2.05. Revision date 8/23/04

Last updated: