テガフール

Partly miscible

29.9 [ug/mL] (The mean of the results at pH 7.4)

Danger

H301 (95.1%): Toxic if swallowed [Danger Acute toxicity, oral]

P261, P262, P264, P270, P271, P280, P301+P316, P302+P352, P304+P340, P316, P321, P330, P361+P364, P403+P233, P405, and P501 (click each P-code to see the statement)

Aggregated GHS information provided per 41 reports by companies from 4 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

L01BC53

L - Antineoplastic and immunomodulating agents

QL - Antineoplastic and immunomodulating agents

Tegafur is an antineoplastic agent that belongs in the class of pyrimidine analogues. It interferes with the 2'-deoxythymidylate (DTMP) synthesis in the pyrimidine pathway, resulting in inhibition of DNA synthesis. In a phase III trial investigating the clinical efficacy of S-1 (tegafur/gimeracil/oteracil) in patients with advanced or recurrent gastric cancer, treatment resulted in a high response rate and was associated with a longer overall survival and longer progression-free survival rate when used in combination with cisplatin. In a meta analysis, triple combination therapy consisting of tegafur, gimeracil and oteracil showed longer survival times and well tolerance in patients with advanced gastric cancer. Tegafur and its active metabolites are potent myleosuppressive agents.

The transformation of 2'-deoxyurindylate (dUMP) to 2'-deoxythymidylate (dTMP) is essential in driving the synthesis of DNA and purines in cells. Thymidylate synthase catalyzes the conversion of dUMP to dTMP, which is a precursor of thymidine triphosphate (TTP), one of the four deoxyribonucleotides required for DNA synthesis. After administration into the body, tegafur is converted into the active antineoplastic metabolite, fluorouracil (5-FU). In tumour cells, 5-FU undergoes phosphorylation to form the active anabolites, including 5-fluorodeoxyuridine monophosphate (FdUMP). FdUMP and reduced folate are bound to thymidylate synthase leading to formation of a ternary complex which inhibits DNA synthesis. In addition, 5-fluorouridine-triphosphate (FUTP) is incorporated into RNA causing disruption of RNA functions.

Hepatic CYP2A6 is the predominant enzyme that mediates 5-hydroxylation of tegafur to generate 5'-hydroxytegafur. This metabolite is unstable and undergoes spontaneous degradation to form 5-FU, which is an active antineoplastic agent that exerts a pharmacological action on tumours. 5-FU is rapidly metabolised by the liver enzyme dihydropyrimidine dehydrogenase (DPD).