Capecitabine

Capecitabine is a fluoropyrimidine carbamate prodrug that is converted in the body into the active metabolite 5-fluorouracil (5-FU). Because thymidine phosphorylase levels are often higher in tumor tissue than in normal tissue, the proportion of 5-FU generated within tumor tissue can be relatively increased. Subsequently, 5-FU is further converted into other active metabolites, such as FdUMP (5-fluoro-2'-deoxyuridine monophosphate), which inhibits thymidylate synthase and blocks dTMP synthesis; FUTP (5-fluorouridine triphosphate), which is incorporated into RNA and interferes with RNA function and protein synthesis; and FdUTP, which is incorporated into DNA, causing DNA abnormalities, blocking cancer cell division, and activating cell death-related pathways.