methotrexate at a glance
Medicine class
Folate antagonist; antimetabolite, immunosuppressant and cytotoxic agent.
Main roles
Controls inflammatory disease and treats selected cancers.
What is methotrexate used for?
Licensing differs between formulations. Selected UK products collectively cover:
Active rheumatoid arthritis in adults.
Severe active polyarticular juvenile idiopathic arthritis where response to non-steroidal anti-inflammatory medicines has been inadequate.
Moderate-to-severe or severe treatment-resistant psoriasis, and severe psoriatic arthritis.
Mild-to-moderate Crohn’s disease in selected adults who cannot tolerate or have not responded to thiopurines.
Selected cancers, including leukaemias, lymphoma, trophoblastic neoplasms, sarcomas and several solid tumours.
Specialist medical management of suitable ectopic pregnancies.
How does methotrexate work?
Methotrexate blocks dihydrofolate reductase and disrupts folate-dependent DNA synthesis. This limits rapidly dividing cells in cancer; in inflammatory disease, immunomodulatory effects and increased adenosine activity at inflamed sites may reduce inflammation.
methotrexate preparations and strengths
Oral solution
Route: Oral
Strengths: 2 mg/mL
Tablet
Route: Oral
Strengths: 2.5 mg, 10 mg
Injection
Route: Parenteral
Strengths: 2.5 mg/mL, 25 mg/mL, 100 mg/mL
How to take methotrexate
Use only the prescribed formulation and follow its labelled schedule exactly.
Swallow tablets with water; they may be taken with or without food. Do not assume a scored tablet divides into equal amounts.
Shake Jylamvo and measure it only with the supplied oral syringe. Swallow while upright and drink water afterwards.
Use a pre-filled pen only after training. It is a single-use subcutaneous injection.
Wash hands after handling oral methotrexate. Avoid skin or eye contact and promptly wash away accidental splashes.
Carry your methotrexate patient card and show it whenever medicines are prescribed, supplied or reviewed.
methotrexate side effects
Common or expected effects
- Nausea or vomiting
- Reduced appetite
- Abdominal discomfort, indigestion or diarrhoea
- Headache, tiredness or drowsiness
- Mouth soreness or ulcers
- Hair thinning
- Increased sensitivity to sunlight
Get urgent medical advice
- Fever, chills or severe sore throat suggesting infection or bone-marrow suppression
- Unexplained bruising, bleeding or blood in urine or vomit
- Persistent cough, chest pain or breathlessness suggesting lung inflammation
- Jaundice suggesting liver injury
- Marked reduction in urine or swelling suggesting kidney injury
- Severe blistering or peeling rash
- Facial or throat swelling, breathing difficulty or collapse
methotrexate in pregnancy
Methotrexate can cause miscarriage and fetal malformations and is contraindicated for non-cancer indications during pregnancy. Pregnancy should be excluded where appropriate, and anyone planning or discovering a pregnancy should contact the specialist promptly. Exceptional cancer or ectopic-pregnancy use requires specialist risk–benefit assessment.
methotrexate interactions
Check all prescribed, pharmacy and complementary products with a clinician or pharmacist. Important examples include:
Trimethoprim or co-trimoxazole
Avoid where possible because additive antifolate effects can cause severe, sometimes delayed bone-marrow suppression.
NSAIDs, including ibuprofen and high-dose aspirin
They may reduce renal clearance and increase toxicity, particularly with kidney impairment or intensive cancer treatment; do not self-treat without checking.
Penicillin antibiotics
They may reduce methotrexate clearance, so toxicity symptoms and monitoring requirements should be reviewed.
Common questions about methotrexate
Answers are fully visible for fast scanning and source review.
Is methotrexate chemotherapy or an immunosuppressant?
It is both. Its folate-antagonist effects are used intensively against some cancers and differently to suppress inflammation in autoimmune disease.
Why does methotrexate require blood tests?
Tests can detect falling blood-cell counts, liver injury or reduced kidney clearance before serious toxicity becomes apparent.
What should I do after a scheduling error?
Do not take another dose. Contact NHS 111 or the treating team immediately, even if you feel well.
Sources
These sources were used to prepare and review this medicine page.
Prepared and reviewed by the iatroX editorial team.