mercaptopurine

mer·cap·to·pu·rine (.)mər-.kap-tə-'pyu̇(ə)r-.ēn n an antimetabolite C₅H₄N₄S that interferes esp. with the metabolism of purine bases and the biosynthesis of nucleic acids and that is sometimes useful in the treatment of acute leukemia

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n.

a drug that prevents the growth of cancer cells and is administered by mouth, chiefly in the treatment of some types of leukaemia (see antimetabolite). It commonly reduces the numbers of white blood cells; mouth ulcers and digestive upsets may also occur. Trade name: Puri-Nethol.

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mer·cap·to·pu·rine (6-MP) (mər-kap″to-puґrēn) [USP] a thiopurine that can be incorporated into the nucleotide 6-thiol MP, an analogue of inosine monophosphate (IMP), which then inhibits new purine synthesis in two places, by serving as a pseudofeedback inhibitor of the first step in the pathway and also by inhibiting the conversion of IMP to adenine and guanine nucleotides. Mercaptopurine is administered orally as an antineoplastic, primarily for treatment of acute lymphoblastic leukemia, and has also been used as an immunosuppressant in treatment of Crohn disease, ulcerative colitis, and severe psoriatic arthritis. Called also 6-mercaptopurine.