Methotrexate

Methotrexate is a type of drug known as a disease-modifying anti-rheumatic drug, or DMARD. These drugs have the effect of dampening down the underlying disease process, rather than simply treating symptoms. Methotrexate reduces the activity of the immune system (the body’s own defence system), so it is always used with care.

Why is methotrexate prescribed?

Methotrexate is used to treat several different types of rheumatic disease, including rheumatoid arthritis and psoriatic arthritis.

When and how do I take methotrexate?

Methotrexate is usually taken in tablet form ONCE A WEEK on the same day. The tablets should be swallowed whole and not crushed or chewed.

Methotrexate tablets are usually 2.5 mg. A 10 mg tablet is also available, although less often dispensed, and to avoid confusion it is recommended that only the 2.5 mg tablet be used. The two strengths are different shapes but are a very similar colour, so you should always check the dose is correct.

Your doctor will advise you about what dose you should take. Usually you will start on a low dose (e.g. 5–10 mg a week). Your doctor may then increase this.

Methotrexate may also be given once a week by injection – subcutaneous (an injection under the skin) or intramuscular (into the buttock or thigh). Methotrexate has also been licensed for intravenous use (injection into the vein). Injected methotrexate is normally only used if the tablets are not well tolerated.

How long does methotrexate take to work?

Methotrexate does not work immediately. It may be 3–12 weeks before you notice any benefit.

What are the possible risks or side-effects?

In some patients methotrexate can cause nausea (feeling sick), diarrhoea, mouth ulcers, hair loss and skin rashes.

Taking methotrexate can affect the blood count (one of the effects is that fewer blood cells are made) and can make you more likely to develop infections. Methotrexate can also affect the liver. You should tell your doctor or rheumatology nurse specialist straight away if you develop any of the following after starting methotrexate:

• a sore throat

• a fever

• any other symptom of infection

• unexplained bruising or bleeding

• jaundice (eyes or skin turning yellow)

• any other new symptom

You should stop methotrexate and see your doctor immediately if:

• any of the symptoms listed above are severe
• you become breathless – in rare cases, methotrexate causes inflammation of the lung with breathlessness
• you have not had chickenpox and you come into contact with someone who has chickenpox or shingles
• you develop chickenpox or shingles.

Chickenpox and shingles can be severe in people on treatments such as methotrexate which affect the immune system. Therefore you may need antiviral treatment, which your doctor will be able to prescribe.

Most doctors prescribe folic acid tablets to patients who are taking methotrexate as this can reduce the likelihood of side-effects. It is often recommended that folic acid should be taken once a week only; some doctors advise that it should not be taken on the same day as methotrexate.

What other treatments could be used instead of methotrexate?

A number of other drugs are used in the treatment of rheumatoid arthritis and related conditions. Your doctor will discuss these other options with you.

Will I need any special checks while on methotrexate?

Because methotrexate can affect the blood count and sometimes cause liver problems, your doctor will arrange for you to have a blood test before you start treatment and regular blood checks while on methotrexate.You may be asked to keep a record booklet with your blood test results, and you should bring this with you when you visit your GP or the hospital. Your doctor may also request a chest x-ray before you start treatment, and sometimes lung function (breathing) tests. You must not take methotrexate unless you are having regular checks.

Can I take other medicines along with methotrexate?

Methotrexate may be prescribed along with other drugs in treating your condition. Some drugs interact with methotrexate, so you should discuss any new medications with your doctor before starting them, and you should always tell any other doctor treating you that you are on methotrexate.

Special care is needed with non-steroidal anti-inflammatory drugs (NSAIDs). You may only take NSAIDs if they are prescribed to you by your doctor. You should also avoid the drugs trimethoprim and co-trimoxazole (Septrin), which may be prescribed for infections.

Methotrexate is not a painkiller. If you are already on painkillers you can carry on taking these as well as methotrexate, unless your doctor advises otherwise.

Do not take over-the-counter preparations or herbal remedies without discussing this first with your doctor, rheumatology nurse or pharmacist.

What about immunisations?

If you are on methotrexate it is recommended that you should not be immunised with 'live' vaccines such as yellow fever. However, in certain situations a live vaccine may be necessary (for example rubella immunisation in women of childbearing age), in which case your doctor will discuss the possible risks and benefits of the immunisation with you.

Pneumovax (which gives protection against the commonest cause of pneumonia) and yearly flu vaccines are safe and recommended.

Can I drink alcohol while on methotrexate?

If you drink alcohol you should only drink it in small amounts because methotrexate and alcohol can interact and damage your liver. Discuss this with your doctor.

Does methotrexate affect fertility or pregnancy?

Methotrexate can reduce fertility and it is likely to harm an unborn baby, so it must not be taken during pregnancy. Both men and women using this drug should take contraceptive precautions. After stopping methotrexate you should continue using contraception for at least 3 months, and some doctors advise up to 6 months. If you are planning a family, or if you become pregnant while taking methotrexate, you should discuss this with your doctor as soon as possible.

What about breastfeeding?

You should not breastfeed if you are on methotrexate. The drug may pass into the breast milk and could be harmful to your baby.

Where can I obtain further information?

If you would like any further information about methotrexate, or if you have any concerns about your treatment, you should discuss this with your doctor, rheumatology nurse or pharmacist.

 

Remember to keep all medicines out of reach of children.

PLEASE NOTE: We have made every effort to ensure that this content is correct at time of publication, but remember that information about drugs may change. This page is for general education only and does not list all the uses and side-effects associated with this drug. For full details please see the drug information leaflet that comes with your medicine. Your doctor will assess your medical circumstances and draw your attention to any information or side-effects that may be relevant in your particular case.

Our drug information is revised annually and published at the start of the year.