Also known as: Maxtrex, Metoject, Jylamvo, Methofill, Nordimet, Zlatal
Methotrexate is an immunosuppressant used for inflammatory conditions such as rheumatoid arthritis, psoriasis and Crohn's disease, and sometimes for cancer. When it is used for autoimmune conditions such as these, it is taken once a week, not every day. Taking it daily by mistake instead of weekly has caused overdoses that were sometimes fatal. The NHS says to contact NHS 111 right away if more methotrexate than prescribed has been taken, including taking it daily instead of weekly.
Methotrexate is available as tablets, an oral liquid and pre-filled injection pens, and for autoimmune conditions it is taken once a week, not daily. (summary of the cited reference, not a prescription)
Onset and duration
The NHS says it can take a few months to notice any benefit, and that the medicine is likely to be working during that time.
Monitoring
Versus Arthritis says blood tests of the blood count, kidney function and liver function are needed before starting, are more frequent at first and become less frequent once treatment is steady. The NHS says a chest X-ray and breathing test may be done before starting. The NHS Specialist Pharmacy Service monitoring page lists hepatitis B among the checks before starting.
Legal status differs between countries and can change; each row cites the document it was taken from and applies only to the country named.
What it is used for
Rheumatoid arthritis
Psoriasis
Crohn's disease
Some cancers
How it works in the body
The NHS says it calms the immune system and helps reduce inflammation. Methotrexate blocks an enzyme called dihydrofolate reductase, which the body uses to make tetrahydrofolate, a form of folate needed to build DNA and RNA. In inflammatory conditions, how low-dose methotrexate works is less clear.
Common side effects
The NHS says the skin may become very sensitive to sunlight. Hospital leaflets list nausea or stomach upset, loss of appetite, diarrhoea, headache and tiredness among the more common side effects.
Hair loss can happen and is not likely to be permanent, according to the NHS.
Versus Arthritis says folic acid tablets are usually prescribed to help reduce unpleasant effects of methotrexate.
Serious: seek help
The NHS says serious side effects are rare.
The NHS says to contact a doctor or NHS 111 straight away about yellow skin or eyes, which can be a sign of liver problems, or a new cough, chest pain or breathlessness, which can be a sign of lung inflammation.
The same NHS list includes signs of infection, such as a high temperature or sore throat, and signs of a blood problem, such as bleeding gums, blood in the urine or unexplained bruising.
The NHS says to call 999 if the lips, mouth, throat or tongue suddenly swell or breathing becomes fast or difficult.
Versus Arthritis says methotrexate can affect the liver and lower the number of blood cells made, which is why regular blood tests are done.
The NHS says to contact NHS 111 right away if more methotrexate than prescribed has been taken, including taking it daily instead of weekly.
Cautions and interactions
When it is used for autoimmune conditions such as these, it is taken once a week, not every day.
Taking it daily by mistake instead of weekly has caused overdoses that were sometimes fatal.
The MHRA says oral methotrexate products used once weekly now come with a patient card that prompts weekly dosing, records the chosen weekday, and is carried to show clinicians who do not know the person's treatment.
The NHS lists a past allergic reaction to methotrexate, severe liver or kidney disease, a blood disorder, an active infection, mouth or stomach ulcers, pregnancy and breastfeeding among reasons it may not be suitable.
The NHS says methotrexate may lower the number of white cells in the blood, which can make infections more likely.
The NHS says to ask a doctor for urgent advice after contact with someone who has chickenpox or shingles.
The NHS says methotrexate is not recommended in pregnancy because it can cause birth defects, and advises speaking to a doctor before trying to get pregnant.
The NHS pregnancy page says methotrexate may affect sperm in men and egg production in women.
NHS hospital guidance advises effective contraception during treatment and for some months afterwards, and the length of time differs between sources.
The NHS says tiny amounts of methotrexate pass into breast milk, and lists breastfeeding among situations where it may not be suitable.
The NHS says it is usually fine to drink alcohol with a low weekly amount of methotrexate, and to ask a doctor if taking a higher amount.
Live vaccines are not recommended during treatment.
NHS Specialist Pharmacy Service guidance says NSAIDs such as ibuprofen can increase the risk of methotrexate toxicity, so they are used only on specialist advice.
Trimethoprim and co-trimoxazole are advised against because of the risk of severe bone marrow suppression.
Interactions
Check interactions
Taking Methotrexate with other medicines? Add them to the checker to see what the official sources say about each pair: the mechanism, general management and monitoring, never a bare "safe".
Interactions documented in the official sources cited on each card. The list covers the medicines represented on this site and is not exhaustive; how the interaction data is compiled.
Aspirin reduces the kidney's excretion of methotrexate, raising its levels and toxicity (bone-marrow suppression, mucositis, liver injury).
Why it can occur
renal clearance
What official information says
UK information lists methotrexate among medicines to tell a doctor about; the BNF advises avoiding aspirin with high-dose methotrexate and monitoring with low-dose.
What to discuss with a clinician
Official guidance: avoided with high-dose methotrexate; with weekly low-dose methotrexate the combination is used only with monitoring.
NSAIDs reduce the kidney's excretion of methotrexate and can raise it to toxic levels.
Why it can occur
renal clearance
What official information says
UK information lists methotrexate among medicines to tell a doctor about; the BNF advises avoiding NSAIDs with high-dose methotrexate and monitoring with low-dose.
What to discuss with a clinician
Official guidance: avoided with high-dose methotrexate; monitored with weekly low-dose methotrexate.
Proton pump inhibitors can reduce the elimination of methotrexate and raise its levels, most importantly with high-dose methotrexate.
Why it can occur
renal clearance
What official information says
UK information lists methotrexate among medicines to tell a doctor about; the BNF advises considering withholding the PPI around high-dose methotrexate.
What to discuss with a clinician
Official guidance: the PPI may be withheld around high-dose methotrexate; low-dose weekly methotrexate is monitored.
Medicines often discussed alongside Methotrexate: used together, compared with it, or acting on the same problem by a different route.
Key facts
Fact
Detail
Brand names
Brand names listed by the NHS include Jylamvo, Maxtrex, Methofill, Metoject, Nordimet and Zlatal.
Type of medicine
Immunosuppressant and disease-modifying drug
Available
On prescription only
Main uses
Rheumatoid arthritis, psoriasis, Crohn's disease and some cancers
Key warning
For autoimmune conditions it is taken once a week, and taking it daily by mistake can be fatal; the NHS says to contact NHS 111 right away if too much has been taken
Monitoring
Regular blood tests
Pregnancy
Not recommended in pregnancy; speak to a doctor before trying to get pregnant
What is methotrexate used for, and how does it work?
Methotrexate is an immunosuppressant used for inflammatory conditions such as rheumatoid arthritis, psoriasis and Crohn's disease, and sometimes for cancer. It is available only on prescription. The NHS says it calms the immune system and helps reduce inflammation. It is not a painkiller, although there may be less pain as symptoms improve. The NHS says it can take a few months to notice any benefit, and that the medicine is likely to be working during that time.
Methotrexate blocks an enzyme called dihydrofolate reductase, which the body uses to make tetrahydrofolate, a form of folate needed to build DNA and RNA. In inflammatory conditions, how low-dose methotrexate works is less clear. Proposed explanations include effects on adenosine release, inflammatory signals and the growth of lymphocytes.
Why is weekly dosing so important?
When it is used for autoimmune conditions such as these, it is taken once a week, not every day. Taking it daily by mistake instead of weekly has caused overdoses that were sometimes fatal. In 2020 the MHRA introduced new measures to reduce the risk of fatal overdose from accidental daily dosing. The MHRA says oral methotrexate products used once weekly now come with a patient card that prompts weekly dosing, records the chosen weekday, and is carried to show clinicians who do not know the person's treatment. Prescribers are asked to write the weekday in full on the prescription. The NHS says to contact NHS 111 right away if more methotrexate than prescribed has been taken, including taking it daily instead of weekly.
What are the side effects?
The NHS says the skin may become very sensitive to sunlight. Hospital leaflets list nausea or stomach upset, loss of appetite, diarrhoea, headache and tiredness among the more common side effects. Hair loss can happen and is not likely to be permanent, according to the NHS. Versus Arthritis says folic acid tablets are usually prescribed to help reduce unpleasant effects of methotrexate.
The NHS says serious side effects are rare. The NHS says to contact a doctor or NHS 111 straight away about yellow skin or eyes, which can be a sign of liver problems, or a new cough, chest pain or breathlessness, which can be a sign of lung inflammation. The same NHS list includes signs of infection, such as a high temperature or sore throat, and signs of a blood problem, such as bleeding gums, blood in the urine or unexplained bruising. The NHS says to call 999 if the lips, mouth, throat or tongue suddenly swell or breathing becomes fast or difficult. Versus Arthritis says methotrexate can affect the liver and lower the number of blood cells made, which is why regular blood tests are done.
Which tests are needed?
Versus Arthritis says blood tests of the blood count, kidney function and liver function are needed before starting, are more frequent at first and become less frequent once treatment is steady. The NHS says a chest X-ray and breathing test may be done before starting. The NHS Specialist Pharmacy Service monitoring page lists hepatitis B among the checks before starting.
The NHS says methotrexate may lower the number of white cells in the blood, which can make infections more likely. The NHS says to ask a doctor for urgent advice after contact with someone who has chickenpox or shingles.
What about pregnancy and contraception?
The NHS says methotrexate is not recommended in pregnancy because it can cause birth defects, and advises speaking to a doctor before trying to get pregnant. The NHS pregnancy page says methotrexate may affect sperm in men and egg production in women. NHS hospital guidance advises effective contraception during treatment and for some months afterwards, and the length of time differs between sources. The NHS says tiny amounts of methotrexate pass into breast milk, and lists breastfeeding among situations where it may not be suitable.
Taking methotrexate with other medicines, alcohol and vaccines
The NHS lists a past allergic reaction to methotrexate, severe liver or kidney disease, a blood disorder, an active infection, mouth or stomach ulcers, pregnancy and breastfeeding among reasons it may not be suitable. The NHS says it is usually fine to drink alcohol with a low weekly amount of methotrexate, and to ask a doctor if taking a higher amount. Live vaccines are not recommended during treatment. NHS Specialist Pharmacy Service guidance says NSAIDs such as ibuprofen can increase the risk of methotrexate toxicity, so they are used only on specialist advice. Trimethoprim and co-trimoxazole are advised against because of the risk of severe bone marrow suppression.
Frequently asked questions
Why does methotrexate need to be taken weekly rather than daily?
When it is used for autoimmune conditions such as these, it is taken once a week, not every day. Taking it daily by mistake instead of weekly has caused overdoses that were sometimes fatal. The NHS says to contact NHS 111 right away if more methotrexate than prescribed has been taken, including taking it daily instead of weekly.
Is methotrexate suitable in pregnancy?
The NHS says methotrexate is not recommended in pregnancy because it can cause birth defects, and advises speaking to a doctor before trying to get pregnant. The NHS pregnancy page says methotrexate may affect sperm in men and egg production in women. NHS hospital guidance advises effective contraception during treatment and for some months afterwards, and the length of time differs between sources.
Can alcohol be drunk with methotrexate?
The NHS says it is usually fine to drink alcohol with a low weekly amount of methotrexate, and to ask a doctor if taking a higher amount.
Why are regular blood tests needed?
Versus Arthritis says blood tests of the blood count, kidney function and liver function are needed before starting, are more frequent at first and become less frequent once treatment is steady. Versus Arthritis says methotrexate can affect the liver and lower the number of blood cells made, which is why regular blood tests are done.
What should be done about chickenpox or shingles contact?
The NHS says methotrexate may lower the number of white cells in the blood, which can make infections more likely. The NHS says to ask a doctor for urgent advice after contact with someone who has chickenpox or shingles.
Connected pages in detail
What each linked page on Anatomy Nexus covers, in a line, for Methotrexate.
Conditions
Rheumatoid arthritisA chronic autoimmune disease in which the immune system attacks the synovial lining of joints.
Inflammatory bowel diseaseChronic inflammation of the gut driven by an abnormal immune response: ulcerative colitis affects the colon's lining continuously from the rectum.
IbuprofenA non-steroidal anti-inflammatory (NSAID) that eases pain, inflammation and fever by blocking prostaglandin production.
Prednisolone and steroidsA corticosteroid tablet that suppresses inflammation and the immune system, used in asthma flare-ups, arthritis.
Drug classes
Antimetabolite DMARDsAntimetabolite DMARDs are a group of disease-modifying medicines; methotrexate is the member covered on this site.
Educational content. Anatomy Nexus provides medical education and does not replace professional medical advice, diagnosis, treatment, prescribing or pharmacist review. Doses, choices and monitoring are decided by a prescriber for an individual; never start, stop or change a medicine on the basis of this page.
