If you take methotrexate once a week, take it on the same day each week. There's usually a reminder on your pill packet and patient card, telling you which day to take your medicine.
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.
Protect your skin from sunlight
Your skin may be more sensitive to the sun while you're taking methotrexate.
Stay out of bright sun and use a high factor sun cream (SPF 30 or above) even on cloudy days. Do not use a sun lamp or sun beds.
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.
Urgent advice: Contact 111 for advice now if:
- 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.
Important
Do not take folic acid on the same day as your methotrexate. It can stop your medicine from working properly.
Tests during treatment
When you first start treatment, you'll have a check-up and blood tests to check your blood, liver and kidneys every 1 to 2 weeks.
These tests are 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.