Pharmacogenetics of uridine diphosphoglucuronosyltransferase (UGT) 1A family members and its role in patient response to irinotecan

Drug Metab Rev. 2006;38(3):393-409. doi: 10.1080/03602530600739835.


Glucuronidation, catalyzed by the glucuronosyltransferase (UGT) superfamily, is a major biotransformation pathway for several drugs, including irinotecan. Irinotecan is commonly used in colorectal cancer chemotherapy. Irinotecan undergoes metabolism in humans and is converted to its active metabolite SN-38, a topoisomerase I inhibitor. SN-38 is inactivated via glucuronidation catalyzed by various hepatic and extrahepatic UGT1A isozymes. Although the role of the UGT1A1 *28 genetic variant has received much attention in altered toxicity upon irinotecan treatment, other UGT1A enzymes also play an important role. This review summarizes pharmacokinetic, toxicologic, and pharmacogenetic studies carried out to date in irinotecan and SN-38 disposition.

Publication types

  • Review

MeSH terms

  • Animals
  • Antineoplastic Agents, Phytogenic / metabolism
  • Antineoplastic Agents, Phytogenic / pharmacokinetics
  • Antineoplastic Agents, Phytogenic / therapeutic use
  • Camptothecin / analogs & derivatives*
  • Camptothecin / metabolism
  • Camptothecin / pharmacokinetics
  • Camptothecin / therapeutic use
  • Glucuronosyltransferase / genetics
  • Glucuronosyltransferase / metabolism*
  • Humans
  • Irinotecan
  • Isoenzymes / genetics
  • Isoenzymes / metabolism
  • Models, Biological
  • Neoplasms / drug therapy*
  • Neoplasms / genetics
  • Neoplasms / metabolism
  • Pharmacogenetics*
  • Polymorphism, Genetic


  • Antineoplastic Agents, Phytogenic
  • Isoenzymes
  • Irinotecan
  • UGT1A1 enzyme
  • Glucuronosyltransferase
  • Camptothecin