About methotrexate
Antimetabolite immunosuppressant
Used for
- Certain cancers, including leukaemia and lymphoma
- Rheumatoid arthritis and severe psoriasis
- Ectopic pregnancy, under specialist supervision
Usual adult dose
Varies greatly by condition; commonly weekly for inflammatory diseases, but cancer regimens differ.
Usual dose in children
Cancer dosing is based on body size and treatment protocol; specialist supervision is essential.
Common side effects
- Nausea, vomiting, mouth sores
- Low blood cell counts and increased infection risk
- Liver or lung problems
- Hair loss and fatigue
Important warnings
- For most non-cancer conditions, take only once weekly; overdose can be fatal.
- Requires regular blood tests and monitoring of liver, kidneys, and blood counts.
- Avoid during pregnancy; it can cause miscarriage and serious birth defects.
- Seek urgent care for fever, unusual bruising, severe breathlessness, or severe diarrhoea.
Pregnancy
Can cause miscarriage and severe birth defects. Avoid during pregnancy; treatment and conception timing require specialist guidance.
Breastfeeding
Generally avoided during treatment; recommendations depend on dose and indication. Specialist guidance is needed.
Interactions
- Trimethoprim or co-trimoxazole can dangerously increase blood problems.
- NSAIDs, aspirin, and some antibiotics may increase toxicity, especially with high doses or kidney problems.
- Live vaccines may cause infection; avoid unless a specialist advises otherwise.
- Alcohol and other liver-toxic medicines can increase liver injury risk.
AI-generated from general medical knowledge, not from this product's official leaflet. It may be incomplete or out of date. Not medical advice — ask a pharmacist or doctor before making any decision.