antifolate chemotherapyAntifolate therapy Oncology The use of an antimetabolite–eg, MTX, to compete with folate, inhibiting dihydrofolate reductase, the enzyme responsible for → inactive dihydrofolate into an active tetrahydrofolate; this block causes a buildup of toxic dihydrofolate, shutting down synthesis of purine nucleotides and thymidylate; AC is used to treat malignancy. See Leukovorin rescue. Methotrexatre
McGraw-Hill Concise Dictionary of Modern Medicine. © 2002 by The McGraw-Hill Companies, Inc.