Why Have I Been Prescribed This Medication?

Azathioprine (also known as Imuran®) 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 your 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 particular condition. Azathioprine is often referred to as a 'steroid-sparing agent'.

How Does It Work?

Azathioprine can be used to help treat these conditions, often in combination with other medicines.

How Long Does It Take To Work?

Azathioprine acts slowly and can take up to a year for full effects to be reached.

What dose do I take?

The dose of azathioprine depends on your weight and the medical condition being treated. Typical doses vary between 25 to 150mg once a day.

How Do I Take It?

Azathioprine is available as 10mg capsules, 25mg and 50mg tablets. A liquid preparation can be ordered if needed.

  • You should always take the medicine as directed by your doctor.
  • Always read the manufacturer's information leaflet as well as this one if possible. There may be additional information there that you could find useful.
  • You should take azathioprine with or immediately after food to help reduce stomach upsets.
  • The tablets should not be cut in half as this can create amounts of dust that could cause side effects to your and those around you.
  • Never take more than the dose prescribed by your doctor. If you or someone else has taken an overdose of azathioprine, contact your doctor or go to the nearest Accident & Emergency department immediately. If possible, take the container with you.

How Long Will I Be Taking It?

The length of time you will be taking azathioprine depends on the condition being treated. Do not stop taking your medicine unless your doctor tells you to, even if you feel well.

Does Azathioprine Interfere With My Other Medicines?

Azathioprine can interact with other medicines. You should tell your doctor which medicines you are taking before starting azathioprine therapy.

  • Do not take allopurinol, a medicine used to prevent gout, without discussing this with your doctor first.
  • Other medicines which interact with azathioprine include co-trimoxazole, trimethoprim and warfarin. Please let your doctor know if you are taking any of these medicines.
  • Always check with your doctor or pharmacist first before starting any new medication while you are taking azathioprine.

It is safe to drink alcohol in moderation while taking azathioprine but it may make nausea worse. You should avoid having 'live' vaccines but most travel vaccines are OK. Check with your doctor or pharmacist first.

Can Taking Azathioprine Cause Any Side Effects?

All medicines can cause unwanted side effects, which usually improve as your body adjusts to the new medicine. During the early weeks of treatment, azathioprine may cause the following side effects:

  • General feeling of being unwell including dizziness and generalised aches and pains.
  • Stomach upsets such as loss of appetite, feeling or being sick and diarrhoea. Taking azathioprine with food can help reduce sickness.
  • Rash
  • Hair loss, although hair often does grow again, even if you carry on taking azathioprine.

As azathioprine affects your immune system it can make you more open to infections. It can also cause problems with clotting of your blood. If you feel generally unwell or develop unexplained bruising, bleeding, sore throat, fever (high temperature) or malaise (lacking in energy, not feeling quite right in yourself), contact your doctor. Also, if you are in close contact with anyone who has chicken pox or shingles, contact your doctor.

Rarely, azathioprine can affect your liver or pancreas. Contact your doctor or pharmacist if you develop worsening diarrhoea, severe stomach pains or jaundice (yellowing of the skin or whites of the eyes).

Do I Need Any Special Checks While on Azathioprine?

As mentioned above, azathioprine can affect your immune system and other blood cells. Although these affects on the blood are rare, it is important that you have regular blood tests to check for early signs of changes in the blood. Your doctor will tell you how often the blood tests needs to be carried out - usually every 2 to 4 weeks for the first few months of treatment and then every 2 to 3 months. The blood tests can be done at the clinic or, with agreement of your GP, at your local surgery.

What Happens If I Forget To Take a Dose?

If you remember withing 12 hours of your dose being due then take your dose as normal. If it is more than 12 hours since your dose was due, do not take a dose and take your next dose at the normal time. Do not double dose. If you begin to miss doses frequently, please let your doctor know.

Is Azathioprine OK With Pregnancy and Breastfeeding?

If you are planning to become pregnant while you are taking azathioprine, you should discuss this with your doctor first. You should not breastfeed if you taking azathioprine.

You can read more about myasthenia and pregnancy click here.

Keep all medicines out of reach of children

Never give any medication prescribed to you to anyone else

It may harm them even if their symptoms are the same as yours