API

Methotrexate (50mg)

Drug classification

Antineoplastic agents (antimetabolite, folic acid antagonist)

Dosage form

Solution for injection

API strength per dosage

50 mg per 2 mL

Dose

Adult and pediatric methotrexate dosing varies by indication; for rheumatoid arthritis: 7.5–25 mg once weekly; for oncology, doses range from 10–30 mg/m² weekly or as per protocol. Dose adjustments required in renal impairment. Always administer under specialist supervision.

Mechanism of action

Inhibits dihydrofolate reductase (DHFR), blocking tetrahydrofolate synthesis, thereby impairing thymidylate and purine nucleotide production, disrupting DNA, RNA, and protein synthesis, leading to inhibition of cell replication, particularly in rapidly dividing cells.

Indications

Treatment of Cancer

Side effects

Abdominal pain Indigestion Loss of appetite Nausea Vomiting Tiredness Mouth sore Decreased white blood cell count

Pregnancy category

Precautions

Contraindications