antimetabolite(redirected from Antimetabolites, antineoplastic)
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1. a substance bearing a close structural resemblance to one required for normal physiological functioning, and exerting its effect by interfering with the utilization of the essential metabolite.
2. a class of antineoplastic agents consisting of antimetabolites of substances required for cell growth and replication; the interference with cell function is phase specific, largely in the S phase of the cell cycle. The group includes cladribine, cytarabine, floxuridine, fludarabine, fluorouracil, mercaptopurine, methotrexate, and thioguanine. See also antineoplastic therapy.
A substance that competes with, replaces, or antagonizes a particular metabolite; for example, ethionine is an antimetabolite of methionine.
antimetabolite/an·ti·me·tab·o·lite/ (an″te-) (an″ti-mĕ-tab´o-līt) a substance bearing a close structural resemblance to one required for normal physiological functioning, and exerting its effect by interfering with the utilization of the essential metabolite.
A substance that closely resembles an essential metabolite and therefore inhibits physiological reactions involving that metabolite.
an′ti·met′a·bol′ic (-mĕt′ə-bŏl′ĭk) adj.
Etymology: Gk, anti + metabole, change
a drug or other substance that is an antagonist to or resembles a normal human metabolite and interferes with its function in the body, usually by competing for its receptors or enzymes. Among the antimetabolites used as antineoplastic agents are the folic acid analog methotrexate and the pyrimidine analog fluorouracil. The antineoplastic mercaptopurine, an analog of the nucleotide adenine and the purine base hypoxanthine, is a metabolic antagonist of both compounds. Thioguanine, another member of a large series of purine analogs, interferes with nucleic acid synthesis. Cytarabine, used in the treatment of acute myelocytic leukemia, is a synthetic nucleoside that resembles cytidine and kills cells that actively synthesize deoxyribonucleic acid (DNA), apparently by inhibiting the enzyme DNA polymerase.
antimetaboliteAntimetabolic agent Pharmacology Any agent–eg, MTX, 6-mercaptopurine, thioguanine, 5-FU, gemcitabine that is a structural analogue of a native cell metabolite, which either inhibits the enzymes of a particular metabolic pathway or is incorporated during synthesis to produce defective product or prevents replication; anti-metabolites are used as chemotherapeutics, antivirals and as immunosuppressants, and include analogues of purines–eg azathioprine, pyrimidines, folic acid–eg aminopterin, MTX See Azathioprine, Methotrexate.
A substance that competes with, replaces, or antagonizes a particular metabolite; e.g., ethionine is an antimetabolite of methionine.
antimetaboliteAn anticancer, or CYTOTOXIC, drug which acts by combining with essential enzymes within cancer cells so as to interfere with their metabolism and growth. To be useful, antimetabolites must be significantly more toxic to cancer cells than to normal cells.
A drug that interferes with a cell's growth or ability to multiply.
Mentioned in: Chemotherapy
a substance bearing a close structural resemblance to one required for normal physiological functioning, and exerting its effect by interfering with the utilization of the essential metabolite.