This information sheet answers some common questions patients ask about methotrexate. Further information can be found in the information leaflet supplied by the manufacturer or from your consultant neurologist, specialist nurse or pharmacist.

Why Have I Been Prescribed This Medication?

Methotrexate is used to treat a variety of conditions such as rheumatoid arthritis, psoriasis, inflammatory bowel disease (e.g. Crohn's disease) and in large doses to treat cancer. Methotrexate is also used to treat neurological disorders. It is often referred to as a 'steroid-sparing agent' or an immunomodulator. This means that it allows the dose of corticosteroids to be kept to a minimum.

How Does It Work?

Methotrexate belongs to a group of medicines called immunosuppressants. Your immune system helps to protect you against infections, however, sometimes it can overreact or react abnormally and cause illness. Methotrexate helps to reduce or suppress the production of antibodies by 'damping down' the activity of the body's immune system.

How Long Does It Take To Work 

Methotrexate does not work immediately; it can take up to eight to 12 weeks before you have any benefit. You may be on other immunosuppressant medication during this time. Methotrexate cannot cure myasthenia and you may need to take it for several years to keep your symptoms under control.

What Dose Do I take?

The dose of methotrexate is determined by your consultant neurologist. The initial starting dose is 7.5mg, and this is increased as necessary by 2.5mg increments to a maximum dose of 15mg weekly. In exceptional circumstances, your doctor may advise higher doses up to 25mg.

How Do I Take It?

Methotrexate is usually prescribed in 2.5mg tablets. However, it is also available as 10mg tablets. The two strengths are different shapes but are of a similar colour. It is important that you keep an up-to-date record of the dose you are taking and always check the strength of the tablet you have been given, each time you get a new prescription.

  • You should always take the medicine as directed by your consultant neurologist.
  • Always read the manufacturers information leaflet as well as this one, if possible. There may be additional information there that you could find useful.
  • Methotrexate should be taken once a week on the same day each week.
  • The tablets should be swallowed whole with a glass of water, after food. Do not chew or crush the tablet.
  • Never take more than the dose prescribed by your neurologist. If you or someone else has taken an overdose of methotrexate, contact your GP or got to the nearest A&E department immediately, taking the medication container with you.

With methotrexate you will also be given a vitamin called folic acid. This should not be taken on the same day as the methotrexate and a simple idea is to take it on a Friday, as F is for folic acid! Folic acid can help protect your body from the side effects of methotrexate.

How Long Will I Be Taking It?

The length of time you will be taking methotrexate depends on the condition being treated. Do not stop taking your medication unless your doctor tells you to, however well you feel.

Does methotrexate Interfere With My Other Medications?

Methotrexate can interact with other medications. You should tell your neurologist and GP which medications you are taking including medications you buy over-the-counter such as cold and flu remedies and herbal remedies, before starting methotrexate.

  • Some antibiotics affect the way that methotrexate works - penicillins including amoxicillin, co-trimoxazole (septrin), trimethropin, tetracycline and chloramphenicol should be avoided.
  • NSAIDs (ibuprofen and naproxen) affect the pharmacokinetics of methotrexate and can increase the risk of methotrexate toxicity. This effect is usually not seen with lower doses and in patients with normal renal function.
  • Proton-pump inhibitors (PPI) such as omeprazole and lansoprazole have been reported to increase the levels of methotrexate. It is advised that all patients taking a PPI should be reviewed to see if therapy is still necessary, and changed to other medication as required.
  • Phenytoin (anti-convulsant) will need monitoring
  • Some anti-malarial drugs
  • Theophylline, which is used to treat asthma

The above is not a complete list so please check with your neurologist, specialist nurse or pharmacist.

You should avoid having live vaccines such as polio and rubella. Most travel vaccines and flu vaccines are safe as they are NOT live vaccinations. It is safe to drink alcohol in moderation whilst on methotrexate, but it may aggravate liver problems.

Can Taking Methotrexate Cause Any Side Effects?

All medications cause unwanted side effects, some of which may improve as your body adjusts to the new medicine. During the early weeks of treatment, methotrexate may cause the following side effects:

  • Stomach upsets
  • Skin rash
  • Hair loss, although hair does grow again even if you carry on taking methotrexate

As methotrexate affects your immune system, it can make you more prone to infections. It can also cause problems with clotting of your blood. If you feel generally unwell or develop unexplained bruising, bleeding, sore throat, fever (high temperature) or malaise, contact your GP. If you are in close contact with anyone who has chicken pox or shingles, contact your GP.

Rarely, methotrexate can cause inflammation of the lung (pneumonitis). If you become breathless or develop a dry cough, you should see your GP immediately.

Do I Need Any Special Checks Whilst On Methotrexate?

Methotrexate can affect the immune system and other blood cells. Although these effects on the blood are rare, it is important that you have regular blood tests to check for early signs of changes in the blood. Blood tests are usually carried out at your GP surgery every week for six weeks, then monthly for six months and then at two to three monthly intervals. It is advised that the blood tests are on the Monday morning before taking the methotrexate or on the Friday before.

It is important that you ask your GP whether the results are satisfactory to continue on methotrexate. The results should be recorded in the monitoring booklet which you can take along to clinic appointments for review. You should show this information to your dentist if you are having any dental treatment and to your pharmacist when you are collecting any other prescribed medications.

What Happens if I Forget To Take A Dose?

If a dose is missed on the normal day, you can take it on one of the following days. Do not take the dose if it is three or more days late. In the following week take the dose on the usual day. Do not double up the dose.

Is Methotrexate OK in Pregnancy and Breastfeeding?

It is not safe to take methotrexate during pregnancy. It is essential that men and women of child bearing potential use a reliable form of contraception during treatment and for at least three months after methotrexate is stopped as methotrexate can damage the developing foetus.

If you are planning to start a family it is essential that you discuss this with your neurologist.

You should not breast feed if you are taking methotrexate.

You can find more information about myasthenia and pregnancy here.

Keep all medicines out of the reach of children

Never Give any medication prescribed to you to anyone else

I may harm them even if their symptoms are the same as yours