methotrexate injection 1 gm/40 ml

Methotrexate works by closely mimicking folic acid. It binds to and blocks an essential cellular enzyme called dihydrofolate reductase (DHFR). By cutting off the cell's ability to utilize active folate, it completely halts DNA, RNA, and protein synthesis. This stops rapidly replicating cells—such as cancer cells, active psoriatic skin tissues, or overactive immune cells—from multiplying, leading to targeted cell death.