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🌱 來自: Capecitabine

Three-step metabolic conversion of capecitabine to fluorouracil

小腸吸收、肝臟轉換、腫瘤作用

• Capecitabine needs three activation steps to become its active form FU.

1. It is → absorbed in the intestine
2. and converted to 5’-DFCR by carboxylesterase,
3. then → to 5’-DFUR by cytidine deaminase in the liver.

• Thymidine phosphorylase (TP) converts 5’-DFUR to the active drug, FU.
  • 5’-deoxy-5-fluorouridine, which is → a prodrug of the chemotherapy agent 5-fluorouracil (5-FU).
• TP is → found at ↣ higher concentrations in most tumor tissue compared to normal healthy tissue.
• The activation of capecitabine occurs in both tumor and normal tissues.