Methotrexate

Methotrexate is a type of medicine called an immunosuppressant. It slows down your body's immune system and helps reduce inflammation.

It is used to treat inflammatory conditions, including:

• rheumatoid arthritis
• psoriasis (including psoriatic arthritis)
• Crohn's disease

It can also be prescribed for other autoimmune conditions such as sarcoidosis.

Methotrexate is available on prescription only.

It comes as tablets, a liquid that you drink, 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.

• For conditions such as psoriasis, rheumatoid arthritis and Crohn's disease, you'll usually take methotrexate once a week.
• It's important to take your dose on the same day each week. If your doctor also gives you folic acid, take it the day after your methotrexate.
• Before and during treatment, you'll have blood tests to check your blood, liver and kidneys.
• You may also have a chest X-ray and a breathing test to check your lungs before starting treatment.
• 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.

Methotrexate can be used by adults and children.

Methotrexate is not suitable for some people. Tell your doctor before taking methotrexate if you:

• have had an allergic reaction to methotrexate or any other medicines in the past
• are pregnant, trying to get pregnant or are breastfeeding
• have severe liver, kidney, or blood disease
• 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)

Doses for inflammatory conditions

For inflammatory conditions such as psoriasis, rheumatoid arthritis and Crohn's disease, the dose 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 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 is 2.5mg to 10mg once a week. It can be slowly increased up to 30mg once a week.

For Crohn's disease, the usual dose to prevent flare-ups is 10mg to 25mg 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.

Taking 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.

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.

Taking methotrexate liquid

Always use the oral syringe that comes with your medicine to measure your dose. It is important to use this syringe so that you get the right amount.

It's a good idea to have a drink of water after taking your medicine.

Having methotrexate injections

You will 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.

Taking folic acid

You may be prescribed folic acid tablets while you're taking methotrexate. This is a man-made 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 are 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.

Tests during treatment

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.

What if I 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.

What if I take too much?

Taking too much methotrexate by accident can cause serious side effects.

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.

Like all medicines, methotrexate can cause side effects, although not everyone gets them.

Common side effects

Common side effects may happen in more than 1 in 100 people.

Speak to your doctor if these side effects bother you or do not go away:

• loss of appetite, feeling or being sick, stomach ache or indigestion
• diarrhoea
• headaches
• feeling tired or drowsy
• hair loss

Serious side effects

Serious side effects are rare and happen in less than 1 in 10,000 people.

Tell your doctor immediately if you get:

• yellowing of your skin and whites of your eyes – 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
• severe skin rash or blisters on your skin, mouth, eyes or genitals – these may be signs of Stevens-Johnson syndrome

Serious allergic reaction

In rare cases, it's possible to have a serious allergic reaction (anaphylaxis) to methotrexate.

These are not all the side effects of methotrexate. For a full list see the leaflet inside your medicines packet.

What to do about:

• loss of appetite, feeling or being sick, stomach ache or indigestion – eat simple meals and do not eat rich or spicy food. It can help to eat and drink slowly and have smaller, more frequent meals. If you're being sick, try taking small, frequent sips of water to avoid dehydration. For stomach ache, putting a heat pad or covered hot water bottle on your tummy may help.
• diarrhoea – drink lots of fluids, such as water or squash, to avoid dehydration. Signs of dehydration include peeing less than usual or having dark strong-smelling pee. Do not take any other medicines to treat diarrhoea without speaking to a pharmacist or doctor.
• headaches, feeling tired or drowsy – rest and drink plenty of water. Do not take non-steroidal anti-inflammatories (NSAIDs), such as ibuprofen. You can try a painkiller such as paracetamol. Do not drink too much alcohol. Do not drive, cycle or use machinery if you feel tired or drowsy. Speak to your doctor if this does not get better.
• hair loss – this is unlikely to be permanent. If hair loss bothers you, talk to your doctor. They may be able to lower your dose or recommend a different medicine.

Methotrexate is not recommended in pregnancy. If you take it in the early stages of pregnancy it can seriously harm your baby.

Methotrexate can stay in your body for several months. If you are planning to try for a baby, you need to stop taking methotrexate at least 6 months before trying to get pregnant.

Ask your doctor about changing to a different medicine before you stop using contraception.

Methotrexate and breastfeeding

Do not take methotrexate when breastfeeding. This is because methotrexate passes into breast milk and can harm your baby.

If you want to breastfeed, ask your doctor if there's a different medicine you can take.

There are many medicines that affect the way methotrexate works.

Children taking methotrexate must not have a "live" 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 these medicines before you start methotrexate:

• non-steroidal anti-inflammatories (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 and 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 interact with methotrexate.

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 are already taking folic acid prescribed by your doctor. Check the ingredients on the labels of any supplements.

There is not enough information to say whether it's safe to take other herbal remedies or supplements together with methotrexate. They are not tested in the same way as medicines.