Tegafur, gimeracil, oteracil (S-1)
Note: this drug is approved in Japan and Europe but not the US. References will be gradually added.
Mechanism of action
From the NCI Drug Dictionary: An orally bioavailable fluoropyrimidine antagonist composed of tegafur combined with two modulators of 5-flurouracil (5-FU) activity, 5-chloro-2,4-dihydroxypyridine (CDHP) and potassium oxonate, in a molar ratio of 1:0.4:1. Tegafur is a prodrug of 5-fluorouracil, an antimetabolite that inhibits thymidylate synthase, DNA synthesis and cell division, and competes with uridine triphosphate, thus inhibiting RNA and protein synthesis. CDHP is a reversible inhibitor of dihydropyrimidine dehydrogenase (DPD), the liver enzyme responsible for rapid catabolism of 5-FU into inactive metabolites. Potassium oxonate preferentially localizes in the gut and inhibits the enzyme orotate phosphoribosyl-transferase (OPRT), thereby decreasing activation of 5-FU in the gut and activated 5-FU-related gastrointestinal toxicity.
Diseases for which it is used
Also known as
- Brand name: Teysuno