Info

🌱 來自: Pharmacogenomics

Non-P450 phase I metabolizing enzymes

• Dihydropyrimidine dehydrogenase (DPD):
  • The 1st & rate-limiting step in catabolism of pyrimidine bases, uracil & thymidine
• 5-FU & capecitabine (prodrug for 5-FU) metabolized by DPD to inactive metabolites in liver
• DPD deficiency leads to
  • increased exposure & prolonged T1/2 of 5-FU → sev. myelosuppression, GI & neurologic tox
• 39 polymorphisms & mts of the DPD gene are known; DPD*2A the most common polymorphism → inactive enzyme in 0.9% of Caucasian pts