Pharmacologic Substance
tegafur-uracil
Definitions related to tegafur-uracil:
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A formulated therapeutic oral agent consisting of a combination of the 5-fluorouracil (5-FU) congener prodrug tegafur (tetrahydrofuranyl-5-fluorouracil) and uracil (1:4). The high concentration of uracil reversibly inhibits the uracil-reducing enzyme dihydropyrimidine dehydrogenase (DPD), thereby inhibiting first-pass DPD-mediated hepatic metabolism of the uracil analogue 5-FU and permitting administration of 5-FU as the orally bioavailable prodrug tegafur. Tegafur is bioactivated to 5-FU by liver microsomal cytochrome P450 enzymes. 5-FU is subsequently converted into its active metabolites 5-fluoro-deoxyuridine-monophosphate (FdUMP) and 5-fluorouridine-triphosphate (FUTP) intracellularly; these metabolites inhibit the enzyme thymidylate synthase and intercalate into RNA, resulting in decreased thymidine synthesis, reduced DNA synthesis, disrupted RNA function, and tumor cell cytotoxicity.NCI ThesaurusU.S. National Cancer Institute, 2021
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A substance being studied in the treatment of some types of cancer. It is a combination of tegafur and uracil. The tegafur is taken up by the cancer cells and breaks down into 5-FU, a substance that kills tumor cells. The uracil causes higher amounts of 5-FU to stay inside the cells and kill them. Tegafur-uracil is a type of antimetabolite.NCI Dictionary of Cancer TermsU.S. National Cancer Institute, 2021
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