This article describes possible side effects of azathioprine oral tablet. You can explore this overview article to learn more about azathioprine, including the drug’s uses, ways to save on cost, and more.
Azathioprine oral tablet is a generic version of the brand-name drugs Imuran and Azasan. Azathioprine also comes in an injectable form, but this form isn’t described in this article. To learn more about this form, talk with your doctor.
Boxed warning: Risk of cancer
Azathioprine oral tablet has a boxed warning for risk of cancer. A boxed warning is the most serious warning from the Food and Drug Administration (FDA).
For details, see the “Side effects of azathioprine in detail” section below.
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More common side effects of azathioprine
Azathioprine oral tablet may cause mild or serious side effects. Below are some of the more common side effects of this medication.
Commonly reported side effects of azathioprine oral tablet include:
- nausea
- fatigue
- muscle or joint pain
- blood cell problems*
- increased risk of infection
* To learn more about this side effect, see the “Side effects of azathioprine in detail” section below.
Mild side effects of azathioprine
Azathioprine may cause certain mild side effects. Most often, mild side effects are temporary and can be easily managed. Tell your doctor or pharmacist if you have side effects that don’t go away or become bothersome.
Mild side effects of azathioprine oral tablet that occurred in studies include:
- diarrhea
- fatigue
- fever
- hair loss
- increased risk of mild infection
- malaise
- muscle or joint pain
- skin rash
- nausea
- vomiting
- mild allergic reaction*
Azathioprine oral tablet may cause more mild side effects than those listed above. For details, see the drug’s prescribing information.
* To learn more about this side effect, see the “Side effects of azathioprine in detail” section below.
Serious side effects of azathioprine
Azathioprine may cause certain serious side effects. If you have any serious side effects from azathioprine oral tablet, call your doctor right away. But if you think you’re having a medical emergency or your side effects feel life threatening, take immediate action. Call 911 or a local emergency number, or go to the nearest emergency room.
After the FDA approves a drug, it tracks and reviews side effects of the medication. Visit MedWatch’s website if you’d like to notify the FDA about a side effect you’ve had with azathioprine.
Serious side effects of azathioprine oral tablet that occurred in studies or have been reported include:
- increased risk of serious infection
- interstitial pneumonitis (a type of inflammation in the lungs)
- liver-related side effects, such as elevated liver enzymes (which can rarely be a sign of liver damage)
- Sweet syndrome*
- blood cell problems*
- risk of cancer*†
- severe allergic reaction*
* To learn more about this side effect, see the “Side effects of azathioprine in detail” section below.
† Azathioprine oral tablet has a boxed warning for this side effect. A boxed warning is the most serious warning from the FDA.
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Common questions about side effects of azathioprine
Here are answers to common questions about side effects of azathioprine oral tablet. If you have other questions, talk with your doctor or pharmacist.
Does azathioprine cause long-term side effects?
Yes, in some cases, azathioprine oral tablet may cause long-term side effects. These can occur if you take the drug for a long time or they may last for a while after you’ve stopped taking the drug.
Examples of long-term side effects reported with azathioprine oral tablet include:
- increased risk of infection, which is present throughout treatment with azathioprine
- blood cell problems*
- Sweet syndrome*
- risk of cancer*†
* To learn more about this side effect, see the “Side effects of azathioprine in detail” section below.
† Azathioprine oral tablet has a boxed warning for this side effect. A boxed warning is the most serious warning from the FDA.
Talk with your doctor to learn more about these side effects and how to manage them. Ask your doctor for more information about how long these side effects of azathioprine may last.
Can azathioprine cause eye-related side effects?
Yes, it’s possible. Eye-related symptoms can happen with Sweet Syndrome, a rare side effect that has been reported with azathioprine.
To learn more about Sweet Syndrome and possible eye-related symptoms it can cause, check out “Side effects in detail” in this article.
Side effects of azathioprine in detail
Below you’ll find details on some of the side effects of azathioprine oral tablet.
Risk of cancer
Azathioprine oral tablet has a boxed warning for the risk of cancer. A boxed warning is the most serious warning from the FDA.
There are rare reports of cancer in people taking azathioprine oral tablet. This side effect is due to how the drug works (azathioprine works by weakening the immune system).
Examples of cancers reported in people taking azathioprine include lymphoma and skin cancer, such as melanoma. Symptoms will vary depending on the type of cancer.
People who receive a kidney transplant are at higher risk of certain cancers, including skin cancer. (Azathioprine is prescribed to help prevent organ rejection following a kidney transplant.)
Ways to manage
While taking azathioprine, take steps to protect yourself from sun and ultraviolet light. Wear sunscreen and clothing that protects your skin, such as long sleeves and pants. This helps lower your risk of skin cancer.
If you have concerns about this risk, tell your doctor. They can discuss how they’ll monitor you during treatment with azathioprine. They can also advise you on what symptoms to watch for and what to do should any appear.
Blood cell problems
In studies and since the drug was approved for use, blood cell problems have occurred in people taking azathioprine oral tablet. This side effect is common, particularly in people who receive azathioprine following a kidney transplant. Blood cell problems caused by azathioprine may be mild or serious.
Blood cell problems reported with azathioprine include the following:
- Leukopenia (low white blood cell count): Leukopenia usually doesn’t cause symptoms, but you might notice more frequent infections.
- Thrombocytopenia (low platelet count): Symptoms of thrombocytopenia include red, purple, or brown bruises and nosebleeds.
- Anemia (low red blood cell count): Symptoms of anemia include fatigue, shortness of breath, and weakness.
Blood cell problems with azathioprine can occur at any time during treatment, even if you’ve taken the drug for a long time without problems.
Taking a higher dose of azathioprine oral tablet can increase the risk of blood cell problems. You’re also at higher risk if you have certain enzyme deficiencies. Your doctor may order a test to check for these deficiencies before your treatment. Or they may order this test if you develop symptoms of blood cell problems while taking azathioprine. Doctors will typically prescribe a lower azathioprine dosage for people with specific enzyme deficiencies. Or they may recommend a treatment other than azathioprine.
Ways to manage
During treatment with azathioprine, your doctor will likely monitor your blood cell counts with blood tests. If these tests show blood cell side effects, your doctor may:
- reduce your azathioprine dosage
- temporarily stop azathioprine treatment until your blood cells recover
- permanently stop treatment with azathioprine, and recommend other treatments for your condition
If you experience symptoms of blood cell problems, tell your doctor. They’ll likely recommend making an appointment for a blood test to check your blood cell counts.
Sweet syndrome
Sweet syndrome has rarely been reported in people taking azathioprine oral tablet. This side effect may be serious.
Sweet syndrome is a skin condition caused by a buildup of neutrophils (a type of white blood cell) in the skin. Symptoms may include:
- painful skin bumps or lesions, which typically come on suddenly
- fatigue
- muscle and joint aches and pains
- conjunctivitis and other eye problems
The exact cause of Sweet syndrome isn’t known. But it’s thought that certain factors, including sun exposure, could play a role in causing it.
Ways to manage
If you experience symptoms of Sweet syndrome, tell your doctor right away. They’ll likely recommend making an appointment for diagnostic tests to determine whether your symptoms are due to Sweet syndrome or another cause.
Corticosteroids, such as prednisone, are a common treatment for Sweet syndrome. Nonsteroidal anti-inflammatory drugs (NSAIDs), such as indomethacin, are another option. Your doctor can review other possible treatments with you if a diagnosis of Sweet syndrome is confirmed. Skin lesions caused by Sweet syndrome may heal on their own over a few weeks or months. But medications can help treat symptoms quickly.
For some people, azathioprine oral tablet can cause an allergic reaction.
Symptoms can be mild or serious, and they may include:
- itchiness
- skin rash
- swelling under the skin, usually affecting eyelids, lips, hands, or feet
- swelling of the mouth, tongue, or throat, which can make it hard to breathe
- flushing (temporary warmth, redness, or deepening of skin color)
Ways to manage
For mild allergic reaction symptoms, such as a mild rash, call your doctor right away. They may recommend treatments to help manage your symptoms. They’ll also let you know whether you should keep taking the medication.
For severe allergic reaction symptoms, such as swelling or trouble breathing, call 911 or your local emergency number right away. These symptoms require immediate medical care because they can become life threatening. If you’ve had a serious allergic reaction to azathioprine oral tablet, your doctor may recommend taking a different medication instead.
Warnings for azathioprine
Below are some factors you may want to discuss with your doctor before taking azathioprine oral tablet.
Boxed warning: Risk of cancer
Azathioprine has a boxed warning for the risk of cancer. A boxed warning is the most serious warning from the FDA.
For details, see the “Side effects of azathioprine in detail” section above.
Other warnings
It may not be safe for you to take azathioprine oral tablet if you have specific health conditions. These are sometimes called drug-condition interactions. Other things may also affect whether azathioprine oral tablet is a safe treatment option for you.
Before taking azathioprine oral tablet, tell your doctor about your health and any medications you take. Things to consider include:
Azathioprine and pregnancy
Usually, azathioprine oral tablet should not be taken during pregnancy. However, there are rare exceptions where it may be taken if the benefits outweigh the risks.
If you’re planning a pregnancy or can become pregnant, talk with your doctor before taking this medication. Your doctor may suggest birth control options to use during treatment with azathioprine.
Azathioprine and breastfeeding
Azathioprine oral tablet should not be taken while breastfeeding. If you’re currently breastfeeding or planning to do so, talk with your doctor before taking this medication. Your doctor may recommend other ways to feed your child during treatment with azathioprine.
Azathioprine oral tablet is not known to interact with alcohol.
However, drinking alcohol could worsen certain side effects of azathioprine if they occur. Examples include diarrhea, nausea, and vomiting.
If you drink alcohol, talk with your doctor about whether it’s safe to consume it during your treatment with azathioprine oral tablet.
What to ask your doctor
This article describes common and serious side effects of azathioprine oral tablet. If your doctor prescribes this medication, they can discuss possible side effects with you. Let your doctor know if you have concerns or questions about treatment with this medication.
Here’s a list of some possible questions you may want to ask your doctor:
- How do side effects of azathioprine compare with those of other medications prescribed following a kidney transplant?
- Do I have a higher risk of side effects than others?
- Does my risk of blood cell problems depend on the dosage of azathioprine oral tablet I take?
- Is my risk of Sweet syndrome higher when I first start azathioprine treatment?
Disclaimer: Optum Perks has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.
