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What are the aims of this leaflet?

This leaflet has been written to help you understand more about methotrexate. It tells you what it is, how it works, how it is used to treat skin conditions, and where you can find out more.

What is methotrexate and how does it work?

Methotrexate is known as a disease-modifying drug or DMARD. It slows the production of new cells by the body’s immune system (the body's immune defence system) and reduces inflammation. It was first used to treat certain types of cancer and was discovered to be an effective treatment for skin and joint diseases when used at lower doses.

Which skin conditions are treated with methotrexate?

The diseases that methotrexate is used to treat include psoriasis, and associated psoriatic arthritis, eczema, pemphigoid, pemphigus, sarcoidosis, scleroderma and dermatomyositis.

How long will I need to take methotrexate before it has an effect?

It may take 3-12 weeks before you notice significant improvement in your condition after starting methotrexate.

When should I take methotrexate?

Methotrexate is usually taken in tablet form once a week and should be taken on the same day each week. It should never be taken every day. The tablets are taken with food and should be swallowed whole, not crushed or chewed. Methotrexate may also be given once a week by injection - either subcutaneous (an injection under the skin), or intramuscular (an injection into a muscle, for example of the buttocks or thigh).

Dermatologists usually prescribe 2.5 mg strength tablets of methotrexate. These tablets must not be confused with the 10 mg tablets, which look similar but are clearly of a much higher strength. Care should be taken to make sure that the correct dose and strength has been prescribed and dispensed to you. You must always check the dose and strength with your chemist or doctor before taking methotrexate.

If you miss taking methotrexate on your normal day, you can take it within 48 hours.  However, if you are more than three days late you should not take the methotrexate that week. You should take your next dose on the usual day the following week.

What dose should I take?

Your doctor will advise you on the weekly dose. Usually a small dose is prescribed at first and the dose is gradually increased until the drug is effective at a safe dose. The dose will be adjusted according to your response to treatment and any side effects you may experience.

What are the possible side effects of methotrexate?

Methotrexate can cause nausea, tiredness, diarrhoea or mouth ulcers. Rarely hair loss and rashes may occur. Methotrexate can affect the white blood cell count so that fewer white blood cells are produced (bone marrow suppression).  You will be more prone to develop infections such as chest infections.

You should see your doctor if:

  • You develop a sore throat, a fever or any other symptoms or signs of infection.
  • You develop mouth ulcers.
  • You develop unexplained bruising or bleeding from the gums.
  • You develop nausea, vomiting, abdominal pain or dark urine.
  • You become breathless or develop a cough.

Folic acid is frequently recommended as a vitamin supplement when taking methotrexate because it may reduce the incidence of side effects such as nausea. 

Liver and lung fibrosis are very rare complications that may occur when the methotrexate has been taken for a number of years.

If you have not had chicken-pox previously and come into contact with someone who has chicken-pox or shingles infection, or if you develop chicken-pox or shingles while you are taking methotrexate, you should see your doctor immediately as you may need specialist treatment.

How will I be monitored for the side effects of methotrexate treatment?

Your doctor will arrange for you to have regular blood tests while you are taking methotrexate. You must not take methotrexate unless you are having these regular blood checks.


The BAD Biologic Interventions Register (BADBIR)

If you have been prescribed methotrexate for treatment of your psoriasis, you may be asked to take part in the national biologics register. This register is to compare the safety of different treatments for psoriasis and to see how well they work. It was set up to monitor some new treatments for psoriasis called biological treatments. The register will give doctors information on how best to use the treatments available for moderate to severe psoriasis. No information will be passed to the register without your informed consent.


Can I have vaccinations whilst on methotrexate?

It is recommended that you should not be immunised using any of the 'live' vaccines such as MMR (measles, mumps, rubella), polio and yellow fever. An 'inactivated' polio vaccine can be given instead of the 'live' one and the 'inactivated' version should also be given to people you are in close contact with, e.g. members of your household.

If you are on methotrexate you should avoid contact with children who have been given the 'live' polio vaccine, for 4-6 weeks after the vaccination.  This precaution is not necessary if inactivated polio vaccine is given. If you require immunisation with a “live” vaccine, methotrexate should be stopped 6 months before the vaccination and not prescribed until 2 weeks after the vaccination has been given. Yearly flu and five yearly Pneumovax vaccinations are safe and recommended.  However, the new nasal flu vaccination is a “live” vaccine and should not be given to patients on methotrexate (see Patient Information Leaflet on Immunisations).

Does methotrexate affect fertility, pregnancy and breast feeding?

Methotrexate can reduce fertility in men, especially at higher doses, and is likely to harm an unborn baby.  Women must not take methotrexate during pregnancy. Men and women should take effective contraceptive precautions whilst taking methotrexate and for at least 3 months after stopping the methotrexate.

If you are planning a family, or if you become pregnant while on methotrexate, you must discuss this with your doctor as soon as possible.

You must not breast feed if you are taking methotrexate.

May I drink alcohol while I am taking methotrexate?

Alcohol does interact with methotrexate. Both alcohol and methotrexate can potentially damage the liver.  It is advisable to keep alcohol consumption to a minimum and well below the national guidelines for safe consumption levels. They can be found online at:

Can I take other medicines at the same time as methotrexate?

Some drugs interact with methotrexate and this can be dangerous. You should always tell any doctor, nurse or pharmacist treating you that you are taking methotrexate.

Special care is needed with non-steroidal anti-inflammatory drugs, such as aspirin or ibuprofen. You should only take anti-inflammatory drugs if your doctor prescribes them for you. Paracetamol preparations are generally safer to take. Do not take 'over-the-counter' herbal or vitamin preparations without discussing this first with your doctor, nurse or pharmacist. You must always avoid antibiotics containing trimethoprim.

Where can I find out more about methotrexate?

If you want to know more about methotrexate, you should speak to your doctor or pharmacist. Please note that this information leaflet does not list all of the side effects of methotrexate. For further details, look at the drug information sheet which comes as an insert with your prescription for methotrexate.

Web links to detailed leaflets:

For details of source materials used please contact the Clinical Standards Unit (

This leaflet aims to provide accurate information about the subject and is a consensus of the views held by representatives of the British Association of Dermatologists: individual patient circumstances may differ, which might alter both the advice and course of therapy given to you by your doctor.

This leaflet has been assessed for readability by the British Association of Dermatologists’ Patient Information Lay Review Panel


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