What are the aims of this leaflet?

This leaflet has been written to help you understand more about methotrexate. It explains what it is, how it works, how it is used to treat skin conditions, and where more information can be found about it.

What is methotrexate and how does it work?

Methotrexate is a type of medicine called an immunosuppressant. This means it suppresses the body’s immune system and lowers immunity. The immune system is important in fighting infections, but sometimes immune system cells mistakenly attack the body’s own healthy tissues, triggering long-term inflammation. Methotrexate reduces the inflammation caused by your condition by dampening down the activity of these cells in the immune system.

Which skin conditions are treated with methotrexate?

Methotrexate is used to treat a number of inflammatory conditions, including psoriasis, psoriatic arthritis, various types of eczema, pemphigoid, pemphigus, sarcoidosis, scleroderma and dermatomyositis. It is not a painkiller, but as a result of reducing the inflammation caused by your condition, you may notice a reduction in pain.

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

After starting methotrexate it may take 3-12 weeks before a significant improvement in the condition is noticed.

When should methotrexate be taken?

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 into the buttocks or thigh).

If methotrexate is not taken on the normal day, it can be taken within 48 hours.  However, if more than three days late methotrexate should not be taken that week. The next dose should be taken on the usual day the following week.

What dose should be taken?

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.

The doctor will advise you of the appropriate weekly dose. Usually a small dose is prescribed at first and then gradually increased until methotrexate is effective at a safe dose. The dose will be adjusted according to the response to treatment and any side effects experienced.

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.

It is important to see a doctor if any of the following symptoms occur:

  • a sore throat, fever or any other symptoms or signs of infection
  • mouth ulcers
  • unexplained bruising or bleeding from the gums
  • nausea, vomiting, abdominal pain or dark urine
  • breathlessness or 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 chickenpox previously and come into contact with someone who has chickenpox or a shingles infection, or if you develop chickenpox or shingles while you are taking methotrexate, a doctor should be seen immediately as specialist treatment may be needed.

How will methotrexate treatment be monitored for side effects?

The doctor will arrange for regular blood tests to be taken during the methotrexate treatment. You must not take methotrexate unless you are having 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 study (BADBIR study). This study is to compare the safety of different treatments for psoriasis and to see how well they work. The study was set up to monitor new biologic treatments for psoriasis. The results will give doctors more information on how best to use the treatments available for moderate to severe psoriasis and what potential side effects there are. No information will be passed to the register without your informed consent.


Can vaccinations be given whilst on methotrexate?

  • The ‘live’ vaccines such as MMR (measles, mumps, rubella), polio, shingles are no longer contraindicated in people taking methotrexate 25 mg (or less) every week. This means that you may be able to have these. But the guidelines advise that your suitability for these vaccines should be decided by your doctors on an individual basis. Advice from infectious disease or travel medicine specialists regarding yellow fever vaccine may be sought, as safety data are limited.
  • If you have never had chicken pox your doctor may recommend vaccination against this before starting methotrexate. If this was not possible and you come into contact with a person with chicken pox or shingles whilst you are taking methotrexate, then you should go to your doctor straight away as you may need special preventative treatment.
  • Yearly ‘flu’ (influenza) and 5 yearly pneumococcal vaccines are safe and should ideally be given to everybody on methotrexate.
  • For more information, see the 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 6 months after stopping methotrexate.

If you are planning, or if you become pregnant while taking methotrexate, this must be discussed with a doctor as soon as possible.

You must not breastfeed if you are taking methotrexate.

Can alcohol be drank when taking methotrexate?

Alcohol interacts 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 other medicines be taken at the same time as methotrexate?

Some drugs interact with methotrexate and this can be dangerous. 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. Anti-inflammatory drugs should only be taken if the doctor prescribes them. Paracetamol preparations are generally safe to take. Do not take 'over-the-counter' herbal or vitamin preparations without first discussing this with the doctor, nurse or pharmacist. Antibiotics containing trimethoprim must always be avoided.

Where can more information be found about methotrexate?

Speak to the doctor or pharmacist for more information. Please note that this information leaflet does not list all the side effects of methotrexate. For further details, please look at the drug information sheet for methotrexate in the prescription pack.

Web links to detailed leaflets:

Please note that the BAD provides web links to additional resources to help people access a range of information about their treatment or skin condition. The views expressed in these external resources may not be shared by the BAD or its members. The BAD has no control of and does not endorse the content of external links.

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

UPDATED APRIL 2012, MAY 2013, DECEMBER 2016, AUGUST 2019, MARCH 2020

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