S-1

S-1 is an orally administered chemotherapy drug used in the treatment of various types of cancer. It is a combination of three different compounds: Tegafur, Gimeracil, and Oteracil.

Composition

S-1 is a combination of three different compounds:

• Tegafur is a prodrug that is metabolized into 5-FU, an antimetabolite and pyrimidine analogue that inhibits thymidylate synthase, an enzyme necessary for DNA replication.

• Gimeracil inhibits the enzyme dihydropyrimidine dehydrogenase (DPD), which is involved in the breakdown of 5-FU. By inhibiting DPD, gimeracil increases the concentration of 5-FU in the body, enhancing its anticancer effects.

• Oteracil is included in the formulation to reduce the gastrointestinal side effects of 5-FU. It inhibits the activation of 5-FU in the gastrointestinal tract, reducing the incidence of gastrointestinal toxicity.

Clinical Use

S-1 is used in the treatment of several types of cancer, including gastric cancer, colorectal cancer, pancreatic cancer, and breast cancer. It is often used in combination with other chemotherapy drugs, such as Cisplatin or Oxaliplatin, in a regimen known as chemotherapy regimen.

Side Effects

Like all chemotherapy drugs, S-1 can cause side effects. The most common side effects include nausea, vomiting, diarrhea, fatigue, and mucositis. Less common but more serious side effects can include neutropenia, thrombocytopenia, and anemia.

See Also

• Chemotherapy
• Cancer
• Tegafur
• Gimeracil
• Oteracil