About methotrexate disodium equivalent to methotrexate
Antimetabolite immunosuppressant
Used for
- Rheumatoid arthritis and other inflammatory autoimmune diseases
- Severe psoriasis
- Certain cancers, including some leukemias and lymphomas
Usual adult dose
Autoimmune diseases: usually 7.5–25 mg once weekly. Cancer doses vary widely by type and treatment plan.
Usual dose in children
Cancer dosing is specialist-directed and varies by diagnosis and body size; not routinely used for childhood inflammatory conditions.
Common side effects
- Nausea, vomiting, mouth sores, or diarrhea
- Low blood counts and increased infection risk
- Liver injury
- Lung inflammation
Important warnings
- Taken weekly for most non-cancer conditions; daily use can be fatal.
- Requires regular blood tests and medical supervision.
- Avoid in severe liver disease, significant immune suppression, or serious blood disorders.
- Seek urgent care for severe infection, unusual bleeding, breathing difficulty, or severe rash.
Pregnancy
Can cause miscarriage and serious birth defects; contraindicated for non-cancer use during pregnancy. Cancer treatment requires specialist assessment.
Breastfeeding
Generally avoided during treatment; recommendations depend on dose and treatment circumstances.
Interactions
- Trimethoprim or co-trimoxazole can dangerously suppress blood counts.
- Some NSAIDs and penicillins may increase methotrexate effects or toxicity.
- Live vaccines may cause infection during treatment.
- Alcohol and other liver-toxic medicines 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 It may be incomplete or out of date.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.