[Futraful and UFT, their metabolic characteristics]

Investigations were made in human on the metabolism of Futraful (FT) and UFT (combination of uracil and FT), both of which are anticancer agents of pyrimidine metabolism antagonist. As a result, it was demonstrated that from the metabolic view point, those drugs essentially have a tumor-selective toxicity. Next, the mechanism of the superior clinical anticancer effect of UFT, compared to FT, was investigated enzymatically, showing the inhibitory effect of uracil on the degradation of 5-fluorouracil generated from FT in the organs and tumor tissues. Discussions were also made for the further development of fluoropyrimidines.