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What is Methotrexate mechanism of action: and explain in detail?
Ans. (a) Inhibit dihydrofolate ReductaseRef. KD Tripathi 6th Ed. / 823METHOTREXATE (MTX)DHFADHFRase---------------THFA* Methotrexate is a highly efficacious antineoplastic drug which inhibits dihydrofolate reductase (DHFRase) enzyme- blocking the conversion of dihydrofolic acid (DHFA) to tetrahydrofolic acid (THFA).* This conversion is essential for formation of an essential coenzyme required for one carbon transfer reactions in denovo purine synthesis and amino acid interconversions.* Methotrexate has cell cycle specific action kills cells in S phase; primarily inhibits DNA synthesis.Also Know*Drug of choice for Mtx toxicity: FOLINIC ACID.