Overview:

What Is Azathioprine?

Azathioprine, also known by the brand name Imuran among others, is an immunosuppressive drug. In simple terms, it helps suppress the immune system, which is exactly what’s needed when the body is either attacking itself (autoimmune diseases) or rejecting something it sees as foreign (like a transplanted organ).

What Does Azathioprine Do?

The main role of azathioprine is to calm down an overactive immune system. It works by interfering with the synthesis of DNA in white blood cells, which play a central role in immune responses. By doing so, it slows the production of these cells and reduces immune attacks.

This makes it incredibly useful in managing:

• Autoimmune diseases like lupus, rheumatoid arthritis, Crohn’s disease, and ulcerative colitis
• Organ transplant rejection, especially in kidney transplant patients

How Common Is Azathioprine?

Azathioprine has been around since the 1960s and is widely used in both rheumatology and transplant medicine. Despite newer alternatives, many doctors still prescribe it because of its long track record, affordability, and effectiveness, particularly in maintaining long-term remission in autoimmune diseases.

Who Can Take Azathioprine?

Azathioprine is typically prescribed to:

• People with autoimmune diseases such as lupus, Crohn’s disease, or multiple sclerosis
• Organ transplant recipients, to prevent rejection
• Patients who don’t respond well to corticosteroids or want to reduce steroid use
• Individuals under close medical supervision due to the drug’s potential side effects

That said, it’s not for everyone. However, your doctor may avoid prescribing it if you have liver issues, certain genetic enzyme deficiencies (such as TPMT or NUDT15), or a history of certain cancers.

Special instruction:

• You will need regular blood tests to check your liver function and blood cell counts. This will help prevent serious side effects.
• Because azathioprine weakens your immune system, you should avoid live vaccines (such as measles, mumps, rubella, or yellow fever) unless your doctor has approved them.
• Azathioprine may increase your sensitivity to the sun and your risk of skin cancer. Always apply sunscreen and wear protective clothing when you are outdoors.
• Inform every healthcare provider (including dentists) that you are taking this medication, especially before any surgeries or medical procedures.
• Alcohol can increase the risk of liver problems while taking azathioprine, so it is best to limit or avoid it.

How Should You Prepare Before Taking Azathioprine?

Before starting azathioprine, your doctor will usually recommend:

• Blood tests to check liver function and enzyme levels, especially TPMT or NUDT15, which affect how your body processes the medication
• Reviewing medications you’re already taking, to avoid interactions
• A pregnancy test or birth control discussion if you’re of childbearing age, since it may affect fertility or pregnancy

This preparation is crucial because azathioprine can affect how your body responds to vaccinations, other medications, and other medical treatments.

How Is Azathioprine Taken?

Azathioprine is most often taken orally, in tablet form. It is usually taken once a day, with or after food, to reduce stomach upset.

The dosage is individualized and may start low, gradually increasing as your body adjusts. You will need regular blood tests to monitor how your liver and bone marrow are handling the medication.

How Should Azathioprine Be Stored?

Azathioprine tablets are relatively low-maintenance but still require proper storage:

• Store at room temperature (between 20°C–25°C / 68°F–77°F).
• Keep the medication away from moisture and heat; do not store it in the bathroom.
• Keep the bottle tightly closed.
• Keep azathioprine out of reach of children and pets.

Risk/Benefit

The benefits of azathioprine include:

What Are the Benefits of Azathioprine?

• Prevent disease flares in autoimmune conditions
• Reducing reliance on steroids, which can have long-term side effects.
• Protect transplanted organs by preventing immune rejection and helping to maintain long-term remission.
• Help maintain long-term remission.

It can be a game-changer for many individuals, restoring quality of life and stability after years of dealing with transplant worries or transplant-related complications.

Risks or side effects

Azathioprine, like all medications, comes with its fair share of risks. Some side effects are mild, while others can be serious:

Common side effects:

• Nausea or vomiting
• Fatigue
• Loss of appetite
• Mild hair thinning

Serious risks:

• Increased infection risk, due to immune suppression
• Liver toxicity or elevated liver enzymes
• Bone marrow suppression, leading to low blood counts
• Pancreatitis
• Increased risk of certain cancers, particularly skin cancer or lymphoma (though rare)

What should you avoid while taking azathioprine?

• Live vaccines (e.g., yellow fever, oral polio)
• Alcohol, which can add stress to your liver
• Exposure to the sun, as it may increase your skin cancer risk  use sunscreen
• Certain medications, such as allopurinol or febuxostat (used for gout), which can interact dangerously with azathioprine

Always inform your healthcare provider about any new medications, supplements, or changes in your health.

How long can you stay on azathioprine?

Some individuals take the medicine  for years, especially those managing chronic conditions or protecting a transplanted organ. The key is regular check-ups and honest communication with your healthcare team. As long as the benefits outweigh the risks  and your body handles it well  long-term use is possible.

Call to Doctor

When should you contact your healthcare provider?

Contact your doctor immediately if you notice:

• Unusual fatigue or bruising
• Fever, chills, or persistent sore throat
• Jaundice (yellowing of the skin or eyes)
• Severe abdominal pain
• Signs of infection