Methotrexate is a type of medicine called an immunosuppressant. It slows down your body's immune system and helps reduce swelling (inflammation).
It's used to treat inflammatory conditions, including:
- rheumatoid arthritis
- psoriasis (including psoriatic arthritis)
- Crohn's disease
It can also be prescribed for cancer.
Methotrexate is available on prescription only.
It comes as tablets, a liquid that you swallow, and pre-filled injection pens or syringes that you inject into your skin. Your specialist doctor may recommend injections if the tablets or liquid are not working for you.
It can also be given as an injection to treat some types of cancer. This is usually done in hospital.
Who can take methotrexate
Most adults and children can take methotrexate.
Who may not be able to take methotrexate
Methotrexate is not suitable for some people. To make sure it's safe for you, tell your doctor before taking it if you:
- have ever had an allergic reaction to methotrexate or any other medicine
- are pregnant, trying to get pregnant or are breastfeeding
- have severe liver or kidney disease, or a blood disorder
- have an infection
- have mouth ulcers, or have been diagnosed with a stomach ulcer or duodenal ulcer
- are due to have a live vaccine (this includes the live flu vaccine usually given to children)
Dosage for inflammatory conditions
For inflammatory conditions such as psoriasis, rheumatoid arthritis or Crohn's disease, the dose of methotrexate will vary. This depends on your condition and blood test results. Always follow the instructions from your doctor.
For rheumatoid arthritis, the usual starting dose for adults is 7.5mg, taken once a week. This can be slowly increased up to 20mg (tablets) or 25mg (pre-filled injection pen or syringe) once a week.
For psoriasis, the usual starting dose for adults is 2.5mg to 10mg, taken once a week. It can be slowly increased up to 30mg once a week.
For Crohn's disease, the usual dose for adults to prevent flare-ups is 10mg to 25mg, taken once a week. This is often called a maintenance dose.
If your child is prescribed methotrexate, the doctor will use their height and weight to work out the right dose.
How to take it
How to take methotrexate tablets
Swallow the tablets whole with a drink of water. You can take your tablets before or after food. Wash your hands after touching the tablets to remove any traces of methotrexate powder.
Your doctor will tell you how many tablets to take each time. You may have to take up to 10 tablets to make up your dose.
How to take methotrexate liquid
Always use the oral syringe that comes with your medicine to measure your dose. It's important to use this syringe so that you get the right amount. If you do not have one, ask a pharmacist for one. Do not use a kitchen teaspoon as it will not measure the right amount.
It's a good idea to have a drink of water after taking your medicine.
Having methotrexate injections
You'll usually go to your GP surgery or a hospital outpatient clinic once a week to have your injection.
Alternatively, you may get a pre-filled injection pen or syringe for you to use at home. Your doctor or nurse will show you how to use this.
Methotrexate treatment for cancer
If you're having methotrexate treatment for cancer, a doctor or nurse will usually give you an injection. You may need to have treatment more than once a week and this will be done in hospital.
How long to take it for
If methotrexate works for you, you may need to take it for several years to control your symptoms.
If you forget to take it
If you forget to take a dose, take it as soon as you remember the next day or the day after.
If your dose is more than 2 days late, contact your doctor or the clinic for advice about what to do.
Never take 2 doses together to make up for a missed dose.
If you take too much
Taking too much methotrexate can cause serious side effects. In some cases, it can be fatal.
Store your weekly methotrexate separately, away from any other medicines that you take daily.
- you've taken more than your prescribed dose of methotrexate
- you've taken your methotrexate daily instead of weekly
Go to 111.nhs.uk or call 111 . If you need advice for a child under 5 years old, call 111.
If you need to go to A&E, do not drive yourself. Get someone else to drive you or call for an ambulance.
Take the methotrexate packet, or the leaflet inside it, plus any remaining medicine with you.
Taking folic acid
You may be prescribed folic acid tablets while you're taking methotrexate. This is a synthetic version of vitamin B9 (also called folate).
Folic acid helps protect the healthy cells in your body and reduces some of the side effects of methotrexate. It can make you less likely to be sick (vomit) or get diarrhoea.
Your doctor will usually start you on one 5mg folic acid tablet, taken once a week. Take it the day after your methotrexate.
If you're still bothered by side effects, your doctor may increase the dose of folic acid. You may need to take 1 tablet 6 times a week, starting the day after you take your methotrexate.
Do not take folic acid on the same day as your methotrexate. It can stop your medicine from working properly.
When you first start treatment, you'll have a check-up and blood tests every 1 to 2 weeks. This is to check if the methotrexate is working and if it's causing any side effects.
Your doctor may increase or decrease your methotrexate dose, depending on the results of your tests.
It's important to record how much methotrexate you take and the results of your blood tests. You'll usually get a booklet for this.
Once you and your doctor have found the right dose and your treatment is working well, you'll have a check-up and blood tests every 2 to 3 months.
Common side effects
These common side effects of methotrexate may happen in more than 1 in 100 people. There are things you can do to help cope with them:
Speak to a doctor or pharmacist if the advice on how to cope does not help and a side effect is still bothering you or does not go away.
Serious side effects
Serious side effects are rare and happen in less than 1 in 10,000 people.
Tell your doctor or contact 111 immediately if you get:
- yellowing of the whites of your eyes, or yellowing of your skin although this may be less obvious on brown or black skin – these may be signs of liver problems
- a persistent cough, chest pain, difficulty breathing, or you become breathless – these may be signs of inflammation of your lungs
- swollen hands, ankles or feet, changes to how often you pee or not peeing at all – these may be signs of kidney problems
- a high temperature, chills, muscle aches, sore throat – these may be signs of an infection
- bleeding gums, blood in your pee, vomiting blood or unexplained bruising – these may be signs of a blood disorder
Serious allergic reaction
In rare cases, it's possible to have a serious allergic reaction (anaphylaxis) to methotrexate.
Methotrexate may increase the risk of problems with your liver or lungs, especially if you take a high dose.
However, your doctor will monitor you very closely and any concerns or problems will be found during routine check-ups.
Other side effects
These are not all the side effects of methotrexate. For a full list see the leaflet inside your medicines packet.
Methotrexate and pregnancy
Methotrexate is not recommended in pregnancy, as it can cause birth defects.
If you're taking methotrexate and want to get pregnant, speak to your doctor. They'll discuss whether you need to switch to a different medicine before stopping your contraception.
If you become pregnant while taking methotrexate, do not stop taking your medicine but speak to your doctor as soon as possible. They'll review your treatment and help you decide what to do next.
Your doctor will only prescribe methotrexate for you while you're pregnant if the benefits of the medicine outweigh the chances of it being harmful.
Methotrexate and breastfeeding
There is not much information about methotrexate and breastfeeding, but it shows that methotrexate passes into breast milk in tiny amounts. Your doctor or specialist will advise what's best for you and your baby.
If your weekly dose of methotrexate is 25mg or less, it may be possible to breastfeed. However, you must not breastfeed for 24 hours after taking your medicine. Your midwife or health visitor can give you advice about how to feed your baby while you wait 24 hours.
If your weekly dose is more than 25mg, your doctor will talk to you about what's best for you and your baby. You may still be able to breastfeed, but it will depend on your dose of methotrexate and any other medicines you're taking.
If you breastfeed while taking methotrexate, your baby will have blood tests to check for any side effects.
If you notice that your baby is not feeding as well as usual, is being sick or has diarrhoea, seem to be getting infections more regularly, or if you have any other concerns about your baby, talk to your health visitor, midwife or doctor as soon as possible.
Methotrexate and fertility
Methotrexate may reduce fertility. It may damage sperm in men and egg production in women.
Methotrexate can cause birth defects if taken during pregnancy. Ask your doctor about changing to a different medicine before you stop using contraception.
Cautions with other medicines
There are many medicines that affect the way methotrexate works.
Always show your patient card to healthcare professionals who may not know about your methotrexate treatment to alert them about your once weekly dose. For example, if you go to hospital or have a change in your care.
Children taking methotrexate must not have a live children's flu vaccine (this usually applies to children aged 2 to 17 years). Adults are given an inactivated flu vaccine and this usually does not cause problems with methotrexate.
Tell your doctor if you're taking any of these medicines before you start taking methotrexate:
- non-steroidal anti-inflammatory drugs (NSAIDs) like ibuprofen, or cough and cold remedies containing NSAIDs
- co-trimoxazole, trimethoprim or other antibiotics for bacterial infections
- medicines that make you pee more (diuretics), such as indapamide or bendroflumethiazide
- epilepsy medicines such as phenytoin or levetiracetam
- theophylline, a medicine used to treat asthma
- medicines used to treat indigestion, such as omeprazole
- folic acid or vitamin supplements that contain folic acid (or folate) – this is because your doctor may prescribe folic acid to take with your methotrexate
These are not all the medicines that may affect methotrexate. Check the leaflet that comes with your medicine.
Mixing methotrexate with herbal remedies and supplements
Do not take vitamin and mineral supplements or any other products that contain folic acid (folate) if you're already taking folic acid prescribed by your doctor. Check the ingredients on the labels of any supplements.
There's not enough information to say whether it's safe to take other herbal remedies or supplements together with methotrexate. They're not tested in the same way as pharmacy and prescription medicines. They're generally not tested for the effect they have on other medicines.
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