Methotrexate is part of a group of medicines called antimetabolites and can be used to treat a variety of conditions. Methotrexate works by decreasing the production of new cells by your immune system reducing its activity and thereby reducing the inflammatory action of your disease. For it to work well, this medicine should be taken as prescribed, even if your symptoms improve.
How do I take methotrexate?
Methotrexate is only always taken once weekly, at the same time each week. The dose is taken after food. Swallow the tablets whole with a glass of water and do not crush or chew them. The tablets come in different sizes and colours, depending on their manufacturer. Moorfields Eye Hospital only dispenses 2.5mg strength tablets. Always double-check your prescription carefully as it is important that you take the correct strength and dose of tablets. If you think you have been given a different strength of tablet than usual, do not take it; instead check with your doctor, nurse or pharmacist as soon as possible.
Your doctor may wish to change the dose of methotrexate you take. If your dose changes, the number of tablets you need to take may change. It is important for us to keep a record of this so please let us know if your dose has been changed.
It may take up to twelve weeks after starting treatment before the ideal dose is reached and your condition starts to improve. Although you may not notice it during this time, it is likely the methotrexate will be working.
What if I forget a dose or take too much?
If you miss taking your methotrexate on your usual day, don’t worry: you can take it either the next day or the day after. For example, if your usual day for taking your dose is Tuesday, you can take it on Wednesday or Thursday.
Do not take the dose if you are three or more days late. Try not to worry as it is unlikely you will have a flare-up of the disease during this time.
In both cases, make sure you take your next dose on your usual day the following week.
If you make a mistake and take too much methotrexate, you may need urgent hospital treatment so contact your doctor or local accident and emergency department immediately. Make sure to keep the bottles/cartons and make a note of how many tablets you think you have taken. If when you are seen, the mistake is not considered serious, you may just need to have your blood checked and miss your next dose. If it is serious, however, you may need urgent treatment.
Can I carry on taking my other medications?
Due to the potential risk of the drug interacting with other medicines, you should tell your doctor and/or pharmacist about any medication you are taking at the moment, or any new medicines you have been prescribed. This includes any medications bought from the pharmacy without a prescription as well as herbal and complementary medicines (e.g. St. John’s Wort). To ensure you remember everything, it may be helpful to bring a list of current medications with you when you see the doctor, nurse or pharmacist. You should also tell us if you are allergic to methotrexate or any other medication.
You must not take co-trimoxazole (Septrin®) or trimethoprim whilst taking methotrexate. These can interact with methotrexate and can be dangerous.
If you have any other health problems that you are trying to treat yourself, inform your pharmacist before purchasing any supplements or treatments. This is to make sure they can be taken with your methotrexate. It is possible that the symptoms you are experiencing might be related to your methotrexate.
A vitamin supplement called folic acid has been shown to help the body cope with the methotrexate, reducing some of the side effects that you may experience. If you are prescribed folic acid it is important that you do not forget to take it. However, please be aware that folic acid tablets should not be taken on the same day as methotrexate tablets. Your doctor, nurse or pharmacist will advise you when it is best for you to take folic acid tablets.
Which tests will I need and how often will I need them?
Before you start treatment, you will need some blood tests to check your blood count, liver and kidneys in addition to a chest x-ray. This information will provide a record for us of how you are before starting treatment and will also check whether methotrexate is suitable for you to take. A very small number of people will be unable to take methotrexate because of lung or liver problems.
When you start methotrexate, you will need a blood test every two weeks for six weeks, then monthly for three months and then at least every 12 weeks. This may vary depending on your condition. In most cases, your blood tests will tell the doctor how your liver and bone marrow is coping with the methotrexate. Occasionally further tests (for example, liver biopsy) might be needed.
Regular blood tests will help us check how well your body is coping with the methotrexate and will help them to decide whether you can continue on the treatment. Depending on how well your treatment is controlling your condition, your doctor may increase or decrease the number of tablets you take.
It is your responsibility to ensure that you have your blood tests on time. It is important that you do not miss these and that you do not take methotrexate unless you are having blood tests regularly.
Previous medical issues
Before starting methotrexate, you should tell the doctor, nurse or pharmacist if you have any kidney, liver or gastrointestinal problems. We also need to know if you have any skin disorders, anaemic conditions, or conditions causing lung/abdomen fluid build-up. Please also inform us if you have an infection, a weak immune system or a tendency to catch infections easily.
Pregnancy, contraception and breast-feeding
Due to methotrexate causing a potential risk to the unborn foetus, effective contraception must be used by both men and women whilst taking this drug. We advise that you talk to your doctor or nurse about effective contraception to use during this time. Do not take methotrexate if you might be pregnant, are breastfeeding or looking to start a family.
Women who become pregnant whilst taking methotrexate should stop their treatment immediately and speak to their doctor. Women who have a partner taking methotrexate should see their doctor for advice if they become pregnant. Methotrexate reduces fertility in both men and women and so it is recommended that both men and women wait at least three months after stopping treatment before trying for a baby.
Alcohol intake
Methotrexate and alcohol may both cause liver damage. If you are taking methotrexate you should ensure that your alcohol intake is well within the maximum limits of 14 units per week, spread evenly over three or more days, on a regular basis. 14 units is equivalent to six pints of average-strength beer or 10 small glasses of low-strength wine.
The risk of liver damage from methotrexate seems to be higher in conditions such as psoriasis than with individuals who have rheumatoid arthritis. This risk is increased by drinking alcohol.
Therefore, if you have psoriasis it is recommended that you avoid alcohol altogether. You may also need an extra blood test (PIIINP) to keep a check on your liver, although sometimes a further test is needed (for example, a needle biopsy of the liver). Your doctor/nurse or pharmacist can provide further advice on this.
Food preparation
Methotrexate may lower your ability to fight infection. There are some reports of bacteria (germs) found in food that may cause a problem to those who are less able to fight infections.
Cooked chilled foods should be reheated thoroughly, and salads washed well; avoid ready-prepared supermarket salads. Do not eat soft cheese made from unpasteurised milk.
Viral infections and vaccinations
If you are taking methotrexate and have never had chickenpox, you may be at risk of severe infection from the virus which causes chickenpox and shingles. Contact your doctor or nurse immediately if you come into close contact with someone who has either of these conditions, as you may need special treatment.
Getting live vaccines are not recommended on this treatment. These include vaccinations for yellow fever, MMR and rubella (German measles). It is therefore important that any doctor/nurse or pharmacist you see is aware that you are on methotrexate and that you should not receive any of these live vaccines.
Please note that it is safe for you to get the flu vaccination and Pneumovax® as they are not live vaccines. It will also not be a risk to you if close relatives and family members get live vaccines. For further advice on this, speak to your doctor, nurse or pharmacist.
Operations/dental treatment/radiotherapy
If you have arranged to have any of the above, please let your doctor or nurse know. If you are having an operation or dental procedure you will be advised to continue with your treatment in most cases. Make sure that your dentist knows you are on methotrexate so they can take this into account when carrying out any dental treatment.
As with most medicines, methotrexate may cause side-effects although this is not the case for everyone.
Most people on low dose methotrexate (25mg or less) cope well and have few, if any, side effects. However, you should be aware of some of the side effects below which may occur. If you experience any of these or any other reactions, do not take your next dose of methotrexate until you have spoken to your doctor, nurse or pharmacist. Once your problem has been looked at, your doctor or nurse will advise you on whether or not you will be able to restart methotrexate.
Possible side-effects include:
When you first start treatment, you may feel unwell with the symptoms described above. This normally settles but may carry on. If this is the case, speak to your doctor/nurse or pharmacist, as something can be done to help. If you vomit within a few hours of taking methotrexate do not take another dose. Make a note that you have been unable to take your tablet and tell your doctor, nurse or pharmacist if this happens again the following week.
Your blood tests will help to keep a check on these. Symptoms that may show problems with the bone marrow or liver include catching infections regularly and bruising or bleeding easily. Your doctor, nurse or pharmacist monitoring your treatment will contact you if there are any problems with your blood test results. Occasionally, changes in your blood may mean that you have to stop taking methotrexate.
If you experience mouth ulcers, or a sore throat or mouth, speak to your doctor, nurse or pharmacist. You may need to have a blood test to check how your body is coping with the methotrexate. In many cases, if your blood tests are normal, you may be given some other medication to treat these problems.
As methotrexate can reduce your ability to fight infections, this can be a problem for people who may be more vulnerable to catching infections. If you think you have an infection, it is important to get advice from your doctor or nurse straight away. For example, a wound that isn’t healing quickly, pain or burning when passing urine, or a suspected chest infection.
Rashes
developing a new rash or having severe itching anywhere on your body. If you get a new rash or have severe itching, seek advice from your doctor, nurse or pharmacist.
Although it is uncommon, this can happen and if it does, it is usually minor. However, if you feel this becomes more than a very slight hair loss, you should discuss it with your doctor. Hair growth usually returns to normal upon stopping treatment.
If you experience any of the following, you should stop taking methotrexate and seek medical advice immediately:
Methotrexate can very occasionally cause severe inflammation of the lungs. The breathlessness caused by methotrexate can come on gradually or over a few days. You may also have a dry cough. If you feel breathless when resting and you don’t have a heavy cold (runny nose and temperature), you should stop your methotrexate and contact your doctor or nurse. It is important that the doctor examines you, as very occasionally methotrexate can cause severe inflammation of the lungs.
Stop treatment and ask your doctor or nurse for advice, as these are sometimes signs of liver problems.
As mentioned earlier, it is important that you are careful about the increased risk of infection whilst on this medication and take sensible measures to protect yourself from catching them. However, if you develop any of the above, stop your methotrexate and get advice immediately from your doctor or nurse
This can sometimes mean that your blood cells are affected by the methotrexate. If you experience this, stop taking your methotrexate and ask your doctor or nurse for advice.
If you have severe diarrhoea and vomiting or are unable to keep liquids down, you may become dehydrated. This could mean that your kidneys are unable to flush out the methotrexate from your blood. We therefore advise that if you have severe diarrhoea or vomiting you stop your methotrexate and get advice immediately from your doctor or nurse.
Please note that if you become severely unwell, or have just had an operation, you may need to stop your methotrexate for a short while. This should only be done after getting advice from your doctor.
Please refer to the packaging and product leaflet for further information or contact the pharmacy department on: 020 7566 2362.
Approval date: March 2024
Review date: March 2026