What is methotrexate?

Why is methotrexate prescribed?

What are the possible side-effects?

What are the risks?

What else should I know about methotrexate?

What is methotrexate?

Methotrexate is a type of drug known as a disease-modifying anti-rheumatic drug (DMARD). These drugs have the effect of dampening down the underlying disease process and helping to prevent joint damage, rather than simply treating symptoms of pain and stiffness. Methotrexate works by reducing the activity of the immune system (the body’s own defence system), which may be overactive in some conditions.

What type of drug is methotrexate?

Methotrexate is a disease-modifying anti-inflammatory drug (DMARD).

What is it used for?

It reduces the activity of the body’s defence system (immune system), which may be overactive in some inflammatory conditions. It therefore helps to prevent damage to the joints.

What does it do?

It is usually given as weekly tablets or by injection, usually under the skin. 

How is it taken?

It is used to treat inflammatory conditions such as rheumatoid arthritis, psoriatic arthritis, juvenile idiopathic arthritis and vasculitis.

Are there any side-effects?

In some patients methotrexate can cause nausea (feeling sick), vomiting, diarrhoea, mouth ulcers, hair loss and skin rashes. It can also make you more likely to develop infections.

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Why is methotrexate prescribed?

Methotrexate is used to treat several different types of inflammatory disease, including rheumatoid arthritis, psoriatic arthritis, juvenile idiopathic arthritis and vasculitis.

When and how do I take methotrexate?

Methotrexate is taken either as a tablet or given as an injection, especially if you have side effects with the tablets. It is also available as a liquid. Methotrexate is usually taken once a week on the same day.

The tablets should be swallowed whole and not crushed or chewed.

You must always wash your hands before and after handling methotrexate.

The two strengths are different sizes 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. In the early stages of a condition it is often treated more aggressively and so the starting dose can range from 7.5–15 mg per week. Your doctor may then increase this if the start dose is not helping your symptoms. But your dose will not usually go higher than 25 mg weekly.

How long does methotrexate take to work?

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

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What are the possible side-effects?

In some patients methotrexate can cause nausea (feeling sick), vomiting, diarrhoea, mouth ulcers, hair loss (usually minor) 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. It can also affect your liver. You should tell your doctor or 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).

Methotrexate also increases the skin’s sensitivity to sunlight so it is important to use high-factor sun cream if you are out in the sun.

You should always read the patient information leaflet included with your medicines package to keep you informed about any possible side effects of your prescribed medications.

What should I look out for?

You should stop methotrexate and see your doctor immediately if:

  • any of the symptoms listed above are severe
  • you become breathless or develop a dry cough lasting more than a month – 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 that affect the immune system such as methotrexate. You may need antiviral treatment, which your doctor will be able to prescribe. Your methotrexate will be stopped if you do develop chickenpox or shingles and restarted when you are better.

Most doctors prescribe folic acid tablets to patients who are taking methotrexate as this can reduce the likelihood of side-effects. The folic acid should not be taken on the same day as methotrexate.

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What are the risks?

Will it affect vaccinations?

If you are on methotrexate it is recommended that you avoid live vaccines such as yellow fever. Your GP will discuss the possible risks and benefits of any vaccinations with you.

If you are in your 70s and are offered shingles vaccination you should seek advice from your rheumatology team – you may be able to have the shingles vaccine if you are on low-dose methotrexate.

Pneumovax (which gives protection against the commonest cause of pneumonia) and yearly flu vaccines do not interact with methotrexate and are recommended.

Can I drink alcohol while on methotrexate?

You should only drink alcohol in small amounts. It is recommended that you keep below national guidelines (1–2 units per day for women and 2–3 units per day for men) because methotrexate and alcohol can interact and damage your liver. In some circumstances your doctor may advise even less, so you should discuss this with your doctor.

Does methotrexate affect fertility or pregnancy?

You should talk to your doctor as soon as possible if you are planning a family, or if you become pregnant while taking methotrexate. Methotrexate may harm your unborn child and increase your risk of miscarriage.  Therefore it is recommended that you stop taking this drug for 3 months and continue with contraception for that period before planning your pregnancy.  It is the same recommendation for men.

Both men and women using this drug should take contraception. After stopping methotrexate you should continue using contraception for at least 3 months, and some doctors advise up to 6 months.

Does it affect 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.

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What else should I know about Methotrexate?

Are there any alternatives?

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. Blood tests will be taken more frequently when you first start treatment with methotrexate, and if your dose changes at any time. You may be asked to keep a record of your blood test results in a booklet, and you should take it 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.

If you become breathless after starting methotrexate, another test can be done to see if your lung function has changed.

You must not take methotrexate unless you are having regular tests.

Can I take other medicines alongside methotrexate?

Methotrexate may be prescribed along with other drugs to treat 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. You should also be aware of the following points:

  • Special care is needed with non-steroidal anti-inflammatory drugs (NSAIDs). You should only take NSAIDs based on the advice of your GP, rheumatologist or pharmacist.
  • 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. If methotrexate works for you, you may be able to reduce your painkillers over a period of time.
  • Some antibiotics can interact with methotrexate – for example, trimethoprim and septrin should not be taken with methotrexate. If you have an infection that requires antibiotics you may need to stop your methotrexate until you are better and off antibiotics.
  • Anti-epileptic medication (phenytoin) and anti-asthma medication (theophylline) should be avoided as they may increase levels of methotrexate in your blood.

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

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