This information provides guidance about the use of mercaptopurine medication to treat autoimmune hepatitis (AIH).
If you need to get in touch with a member of the team about this medicine, or anything else to do with your liver disease, please use the contact details below:
Leeds Liver Unit
Dose of Mercaptopurine
A sample of a Mercaptopurine dosage record can be found on page three of the resource LN005169 Mercaptopurine For Treatment of Autoimmune Hepatitis
Blood test monitoring
Blood tests are required regularly on mercaptopurine. Initially, this is every two weeks for the first two months and then monthly, for four months. Once you are on a stable dose, you will need this every three months. These will be arranged through the specialist nurses.
A sample of a blood test monitoring record can be found on page three of the resource LN005169 Mercaptopurine For Treatment of Autoimmune Hepatitis
In addition to mercaptopurine, you should continue your dose of prednisolone.
The use of mercaptopurine to treat autoimmune liver disease tells you:
- how the medicine works;
- how you should take it; and
- whether there are any side-effects.
Why have I been given this leaflet?
The information will help you to remember what your doctor has told you about this medicine. It will also help you to decide whether you want to go ahead with the treatment.
For most medicines, information is provided by the manufacturer in the medicine package. In the UK, this medicine does not have a licence for use in autoimmune liver disease so the leaflet in the medicine package doesn’t tell you everything you need to know. We have written this guidance to give you some extra information.
What is mercaptopurine and how does it work?
Your blood contains both white and red blood cells. The white cells in the blood form part of the immune system and these can cause damage to the liver. Mercaptopurine helps to reduce the effectiveness of the white blood cells and is used to try to reduce the inflammation and scarring they cause in the liver tissue.
Mercaptopurine does not work immediately and it can take weeks or a few months before any benefits are noticed.
How should I take mercaptopurine?
- Mercaptopurine is usually taken as a tablet once per day and your doctor may increase this as necessary. The dose you are given will depend on your body weight.
- Depending upon how well the tablets work for you, the dose and number of tablets that you need to take may change.
- The tablets should be swallowed with a glass of water, with or after food. Take at the same time each day in relation to food. Mercaptopurine should not be taken with milk or dairy products (should ideally be taken at least one hour before or
- two hours after milk or dairy products).
- Take care to handle the tablets as little as possible and wash your hands after handling them.
- If you miss a dose, you should not ‘double up’. Take the next dose at the normal time and completely omit the missed dose.
- If you miss several doses, then contact your doctor or specialist nurse for advice on what to do next. If you can’t contact them straightaway; for example, if it is a weekend or you are on holiday, then let them know when you can..
When should mercaptopurine not be used?
Please tell your doctor if you have any of the conditions listed above or in the manufacturer’s leaflet.
Pregnancy and Breastfeeding
Talk to your doctor if you are pregnant, plan to get pregnant or think you are pregnant to ensure Mercaptopurine is still appropriate.
Mercaptopurine is one of the safer options in pregnancy; therefore, please do not stop taking Mercaptopurine if you discover you are pregnant without discussing with the team.
Mercaptopurine can also be found in breast milk. If you are breastfeeding or planning to breastfeed, talk to your doctor or pharmacist before taking Mercaptopurine.
Do I need any special checks while on mercaptopurine?
Mercaptopurine reduces the production of blood cells which can put you at risk of infections and can sometimes affect the liver. Blood tests will show if you are developing any side-effects. If you are being affected, your treatment will be changed or stopped immediately.
It is important that you do not miss your blood tests. You must not take mercaptopurine unless you are having regular blood tests.
Are there any side-effects?
Most medicines cause side-effects. The manufacturer’s leaflet contains a list of the known side-effects for this medicine.
If you have any of the following, tell your doctor immediately.
See your doctor if you develop any new symptoms after starting mercaptopurine.
Will mercaptopurine affect any other medicines?
A full list of medicines that can interfere with mercaptopurine can be found in the manufacturer’s patient information leaflet found in your box of medicines. If you take any of the following medications, tell your doctor or pharmacist and they will advise you.
Tell your doctor or pharmacist about all the other medicines you take. This includes any medicines you have had prescribed by another doctor as well as medicines bought from a pharmacy or supermarket and any herbal remedies.
Whenever you are prescribed a new medicine or want to buy a medicine e.g. from a pharmacy or supermarket, it is important that you tell the doctor or pharmacist about all the medicines that you take, including mercaptopurine. You should also tell your dentist when you see him / her.
Will mercaptopurine affect any vaccinations?
- Live vaccinations should be avoided in patients taking mercaptopurine and certain non-live vaccinations may be less effective.
Which vaccinations are safe?
- The pneumonia vaccine, flu vaccine are safe and COVID vaccines are all safe and recommended in immunosuppressed patients.
Can I drink alcohol while I am taking mercaptopurine
- Yes, it is safe to drink alcohol while you are taking mercaptopurine; however, large quantities of alcohol should be avoided. It is recommended that you do not exceed the national guidelines.
Where should I store mercaptopurine at home?
- Store mercaptopurine in a cool, dry place away from direct sunlight.
IMPORTANT
ENSURE THAT ALL MEDICINES ARE STORED OUT OF REACH OF CHILDREN.
Where do I get my next supply?
When you are on a steady dose of mercaptopurine, your GP should take over prescribing it. Until then, this will be supplied when you come to the clinic or via your nurse specialist.
You must make sure you get any repeat prescriptions to the pharmacy in good time. The pharmacy may not have the medicine in stock and may need a few days to arrange a supply.
How can I find out more?
Your agreement should be obtained before prescribing any medicine.
This information has been written to provide general guidance about mercaptopurine. If you have any further questions or concerns, please get in touch with the team using the contact details above.
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