NCIt definition : A diaminopyrimidine folate antagonist with potential antineoplastic activity. Metoprine
inhibits dihydrofolate reductase, resulting in decreased cellular folate metabolism
and cell growth; it also inhibits histamine-N-methyltransferase, resulting in decreased
histamine catabolism. Lipid-soluble metoprine is capable of crossing the blood-brain
barrier. (NCI04);