Gen-Azathioprine

Brand Name:Apo-Azathioprine, Novo-Azathioprine, Imuran

Prescription needed: Yes

What is this drug used for?

Azathioprine is most commonly used to prevent the body from rejecting organs that have been transplanted (for example, liver and kidney). It works by preventing the body’s own immune system from damaging the transplanted organ. It can also be used for other conditions where the body’s own immune system is causing problems. Some of these conditions are called systemic lupus erythematosus, polymyositis, dermatomyositis, myasthenia gravis and rheumatoid arthritis. It is usually used in these situations when other medications are not working.

Is there any reason not to take this drug?

You should not take this drug if you are allergic to azathioprine, 6-mercaptopurine or if you are pregnant. As well, this drug should be avoided or used with extreme caution in individuals who have previously taken medications called alklyating agents such as cyclophosphamide, chlorambucil, mephalan. Before taking this medication, tell your doctor specifically if you have or have ever had:
  • any blood problems (bruising, bleeding, anemia, low white blood cells)
  • chicken pox or shingles (herpes zoster)
  • problems with frequent infections
  • problems with your kidney or liver
  • a condition called pancreatitis
  • gout that requires you to take allopurinol

What about possible side effects?

The most common and sometimes serious side effects of azathioprine involve the stomach and the blood. These side effects are usually related to the dose and duration of therapy. These include:
  • nausea, vomiting (this may be less if the medication is divided throughout the day and taken with food)
  • a condition called thrombocytopenia or leukopenia (usually with long-term therapy or in people who have risk factors; contact your doctor immediately if you experience unusual bleeding, bruising, unexplained sore throat, fever, chills, or other signs of infection)
  • liver problems (contact your doctor if you experience unexplained nausea, vomiting, stomach pain, fatigue, loss of appetite, dark urine, yellowing of the skin and/or eyes)
  • hair loss
  • not feeling hungry
  • increase chance for infections
  • a condition called pancreatitis (call your doctor if you experience severe stomach pain with vomiting)
  • increased chance for some cancers (rare and with longer-term therapy or with other drugs that can change the body’s immune system)
This is not a complete list of side effects. If you are concerned about these or other unusual symptoms while taking this medication, ask your doctor and/or pharmacist for more information and advice.

What if I am taking other drugs?

Always provide your doctor with a list of all other drugs you are taking (including over-the-counter medications and herbal/natural products) as they may interact with and/or may change the safety or effectiveness of either drug. Tell your doctor specifically if you are taking any of these drugs as he/she may need to make changes or monitor you more closely:
  • ACE inhibitors (e.g. ramipril, enalapril, lisinopril) - increases chances for decreasing the white blood cells in the blood)
  • allopurinol (increases the amount of azathioprine in your blood and increase the chances of side effects) - if used together, the dose of azathioprine must be decreased
  • corticosteroids (e.g. prednisone, dexamethasone)
  • cyclosporine (may decrease the amount of cyclosporine in the blood)
  • cotrimoxazole
  • chlorambucil, cyclophosphamide
  • cyclosporine
  • mercaptopurine
  • methotrexate (may increase chances for some side effects)
  • trimethoprim
  • warfarin (may decrease the amount of warfarin in the blood)
  • live vaccines (may increase the chances for infection)

This is not a complete list of drug interactions. Ask your doctor or pharmacist to review your list of medications.

Other information:

Lab Tests: Your doctor will order blood tests regularly. These tests are necessary for the doctor to check you for side effects.

Vaccines: Due to the increased risk of infection both during and after treatment with this drug, it is important not to have any vaccinations or skin tests without first consulting your doctor. Some vaccines are not recommended. Family members living in the same household should not take oral polio vaccine since there is a chance they could pass the polio virus on to you. Also, avoid anyone who has recently taken oral polio vaccine.

Children: Lower doses are necessary

Seniors: Lower doses are necessary.

Pregnancy: Should be avoided if possible as this medication could cause harm to the baby.

Women who are nursing: Not typically recommended. Talk to your doctor.

People who drive or operate machinery: No known problems.

Overdose: An overdose will cause abdominal pain, diarrhea, nausea and vomiting. Call your doctor immediately. If you experience any unusual reactions or if you seriously exceed the recommended dosage, call your doctor or 911.

Stopping the drug: Always talk to your doctor before you stop taking this drug. Suddenly stopping treatment could cause rejection of a transplanted organ or skin graft.

If you miss a dose: Take as soon as you remember, then return to regular dosing schedule. If you miss more than two doses, tell your doctor. Never take a double dose. If you are unsure of what to do, talk to your doctor or pharmacist.

Storage conditions: Closed container; cool, dry location away from excess moisture (not in the bathroom); direct light, always out of reach of children.

Alcohol: No known problems. If you drink, always drink in moderation.

Dietary Precautions: None, however taking azathioprine with or after meals may help decrease stomach upset.