From Wikipedia, the free encyclopedia
Jump to: navigation, search
Combination of
Tegafur Antineoplastic drug
Gimeracil Enzyme inhibitor
Oteracil Enzyme inhibitor
Clinical data
Trade names Teysuno
AHFS/Drugs.com UK Drug Information
Licence data EMA:Link
  • Contraindicated
Legal status
Routes of
CAS Registry Number 150863-82-4
ATC code L01BC53
PubChem CID: 54715158

The combination drug tegafur/gimeracil/oteracil (trade name Teysuno, and TS-1 in Japan[1]) is used for the treatment of advanced gastric cancer.[2] It is also being developed for the treatment of hepatocellular carcinoma.[3]

Mechanism of action[edit]

Tegafur is the actual chemotherapeutic agent. It is a prodrug of the active substance fluorouracil (5-FU).

Gimeracil inhibits the degradation of fluorouracil by reversibly blocking a dehydrogenase enzyme. This results in higher 5-FU levels and a prolonged half-life of the substance.

Oteracil mainly stays in the gut because of its low permeability, where it reduces the production of 5-FU by blocking the enzyme orotate phosphoribosyltransferase. Lower 5-FU levels in the gut result in a lower gastrointestinal toxicity.[4]


  1. ^ TS-1.jp, Taiho Pharmaceutical
  2. ^ UK Drug Information
  3. ^ http://www.biocentury.com/BCIQ
  4. ^ A. Klement (22 July 2013). "Dreier-Kombination gegen Magenkrebs: Teysuno". Österreichische Apothekerzeitung (in German) (15/2013): 23.