Overview
Azathioprine medicine for autoimmune hepatitis
Autoimmune hepatitis (AIH) is a long-term liver condition, usually lifelong.
Autoimmune means your body’s immune system (the body’s defence against illness) attacks your body’s own cells.
Azathioprine is a medicine that helps to treat this condition. It suppresses the body’s immune system to treat inflammation.
Azathioprine acts slowly, so it can be up to 3 months before any benefits are seen.
The length of treatment depends on each person, but it is likely to be for several years and longer in some cases. Many patients need to continue treatment long term to keep their disease under control.
Before you start the medicine
You will need some blood tests to make sure it's safe for you to start taking the medicine. These may include tests to check:
- your blood count
- liver and kidney function
- TPMT, to measure the amount of enzyme you have in your blood that breaks down azathioprine
- hepatitis B
- hepatitis C
- Epstein-Barr virus, which causes glandular fever
- HIV
- chickenpox
We strongly recommend you have the vaccine against strains of pneumonia.
You should also have the flu vaccine every year while taking the medicine.
Your GP practice can arrange these for you.
How to take the medicine
The amount (dose) depends on your weight. Typically doses vary between 25mg and 200mg each day. This might be changed during your treatment.
Azathioprine is usually available as 25mg and 50mg tablets.
You should take each dose with or immediately after food to help reduce stomach upset. The medicine should be swallowed whole with a glass of water.
People usually take the medicine in the morning but taking it before going to bed can help if you're having problems with feeling sick.
In most cases the full dose is taken at the same time but sometimes we may recommend splitting the dose throughout the day.
If you forget to take azathioprine
If you remember within 12 hours of your missed dose, take your dose as normal.
If it's more than 12 hours after you should have taken the medicine, do not take that dose, and take the next dose as planned. Never take two doses at the same time to make up for a missed dose.
Try not to forget any doses. Azathioprine works slowly so if you regularly forget the medicine you will have a lower level of it in your blood, potentially making it less effective. Try setting reminders on your phone to remind you to take your medicines.
Regular blood tests
When you start taking azathioprine, you will need regular blood tests every few weeks.
Monitoring blood tests are essential. If these are not done, your prescription might be withheld until you have your blood test.
If your blood tests are stable after 3 months of treatment, you could continue to have them checked every 3 months with your GP.
When you start taking the medicine our specialist doctors and pharmacists monitor you for side effects or abnormalities on your blood tests. You should expect to have regular appointments or phone calls from them.
We also monitor the levels of azathioprine in your blood, and might adjust your dose depending on the results.
Side effects of azathioprine
Azathioprine works by suppressing your immune system. This means you will be more likely to get an infection. Contact your GP if you begin to feel unwell and think you might have caught an infection.
Everyone responds differently to the medicine but possible side effects include:
- feeling sick (nausea), especially at the start of treatment. (we might make changes to how and when you take the medicine)
- flu-like symptoms including headache, muscle ache and feeling generally unwell (you might feel like this at the start of treatment but this often goes away within a few weeks)
- headache
- diarrhoea
- dizziness
- hair loss, although this can often get better while you continue treatment
- rashes
More serious side effects
More serious side effects will require closer monitoring and, in some cases, we may decide to stop the medicine.
Pancreatitis (inflammation of the pancreas) happens in about 1 in 30 people.
Your regular blood tests will also check for early signs of:
- a reduction in the number of red cells, white cells and platelets produced (this is normal)
- serious infection (that might need treating with antibiotics)
- abnormal liver function (this happens to about 1 in 20 people)
Call a GP, our team or NHS 111 immediately if you:
- notice any unexplained signs of bruising or bleeding
- have a high temperature (fever)
- notice jaundice (yellowing of the eyes or skin)
- have severe upper stomach pain
- notice a rash after starting the medicine
Go straight to your nearest emergency department (A&E) if you feel very unwell.
Azathioprine increases the skin’s sensitivity to the sun, so increases the risk of some types of skin cancer. Wear protective clothing and use a high sun protection factor (SPF 50) sun cream.
Lymphoma is a type of cancer affecting the lymph glands. The risk of getting this is higher than in the general population but it remains very rare (1 in 2,500 people).
Taking azathioprine with other medicines
Azathioprine can interact with other medicines.
Before you start taking azathioprine, you should let your doctor know about all the medicines you take. This includes anything prescribed for you, and any medicines you buy from a shop or pharmacy (including herbal and homeopathic remedies).
While you are taking azathioprine, you should always check with your doctor or pharmacist before starting any new medicines.
A medicine called allopurinol, used to treat gout, interacts with azathioprine so they should not usually be taken together. However, in some cases allopurinol will deliberately be prescribed by your specialist team, with a low dose of azathioprine, if you have lots of side effects or abnormal blood tests with azathioprine.
Other medicines such as co-trimoxazole, trimethoprim and warfarin can also interact with azathioprine.
You should ideally avoid ‘live’ vaccines when you are taking azathioprine, and for at least 3 months after stopping it. If you are considering having vaccinations check with your doctor or pharmacist first.
Drinking alcohol while taking azathioprine
We recommend you keep well within the national recommended limits of alcohol (maximum of 14 units a week).
14 units is about the same as 6 pints of average-strength beer, or 10 small glasses of lower-strength wine.
Any amount of alcohol can damage the liver, especially if you have an underlying condition such as autoimmune hepatitis. Depending on the state of your liver, your clinician might ask you to avoid alcohol completely.
Pregnancy and breastfeeding
The most important thing is that your AIH is as controlled as well as possible during pregnancy.
It's important you tell us if you are pregnant or planning on getting pregnant so that we can review all of your medicines and monitor you more closely.
Our team can discuss the risks and benefits of continuing azathioprine during pregnancy. Many people continue to take azathioprine safely throughout their pregnancy.
Getting a repeat prescription
After your hospital specialist has started you on azathioprine, they'll advise your GP what dose to prescribe.
Your first prescriptions will be given to you by the hospital until your GP has agreed to prescribe them for you. If your GP does not agree to prescribe your azathioprine, your prescriptions will continue to be supplied from our hospital.
If any changes to the dose are needed, the hospital will tell your GP.
Support and more information
For more information about autoimmune hepatitis please visit the British Liver Trust or call the helpline 0800 652 7330.