Why have I been prescribed this medication?

Azathioprine is used to treat a variety of medical conditions such as rheumatoid arthritis, certain skin disorders, inflammatory bowel disease and chronic lung diseases. It is also used as an anti-rejection medicine after organ transplants. The doctor that prescribed this medicine for you should tell you about your condition and why azathioprine is being prescribed. Your doctor may also give you more specific information about the use of azathioprine for your condition. Azathioprine is often referred to as a 'steroid-sparing agent'.

How it works

Azathioprine works to suppress the immune system to dampen down symptoms of myasthenia. This is known as immunosuppression. In autoimmune myasthenia, the body produces antibodies that target the acetylcholine receptor, blocking it and preventing successful transmission between the nerve and muscle cells. Azathioprine suppresses the immune system and therefore the production of these antibodies.

How it is delivered

Azathioprine is prescribed orally to be taken daily and the dosage is weight-based. It is important if a daily dose is missed not to double dose, simply return to schedule the next day. If you take multiple doses a day, it is fine to combine with the next dose that day. If more than one dose is missed, check with your prescribing doctor for instructions.

When you have it and how long you will be taking it

You will typically take Azathioprine daily. The length of time you will be taking Azathioprine depends on the condition being treated. Do not stop taking your medicines unless your doctor tells you to, even if you feel unwell.

Side effects

All medicines can cause unwanted side effects which usually improve as your body adjusts to the new medicine. It is quite common to experience nausea when you first begin taking Azathioprine or have an increase in your dose. There are also examples of adverse side effects to remain vigilant for, including:

  • High temperature
  • Muscle or joint pain
  • Diarrhoea

If any of these symptoms occur, contact your doctor immediately.

Please check the patient information sheet supplied with your medication for a more detailed list of possible side effects. If any side effects disclosed concern you, seek reassurance from your doctor or the team at myaware for more information.

Known UK suppliers

AAH Pharmaceuticals Ltd, Alliance Healthcare (Distribution) Ltd, Healthcare Pharma Ltd, Medihealth (Northern Ltd), Phoenix Healthcare Distribution Ltd, Sigma Pharmaceuticals Plc, Tillomed Laboratoris Ltd, Viatris UK Healthcare Ltd.

FAQ (what else do I need to know?)

  • For those it helps, Azathioprine is known to provide gradual improvement and takes time and patience, sometimes 3-12 months, for results to be seen.
  • Immunosuppressant agents may increase the risk of infection, and it is important to notify your doctor if you develop persistent signs of infection.
  • As Azathioprine can sometimes affect your liver, kidneys, or bone marrow, you will have blood tests regularly to check their function.
  • You can take Azathioprine while pregnant and breastfeeding, but always consult with your doctor first.
  • Azathioprine can affect how some medications work, examples are: allopurinol, warfarin, co-trimoxazole, trimethoprim, and chemotherapy. Tell your doctor if you are undergoing treatment with any of these.
  • You can drink alcohol while being treated with Azathioprine. There is a chance that it may make nausea worse.
  • You should avoid having ‘live’ vaccines, but most travel vaccines are OK. Check with your doctor or pharmacist first.
  • Azathioprine treatment can lead to an increase in the risk of developing skin cancer. If taking azathioprine, please be vigilant when in the sun and wear protective clothing, use sunscreen, and seek shade where possible.
  • If possible, take azathioprine soon after meals or snacks, as it works best if taken with food.

Read more on our Azathioprine information sheet.

Click here to report a side effect to the MHRA.