Identification of human UDP-glucuronosyltransferase enzyme(s) responsible for the glucuronidation of 3-hydroxydesloratadine

Biopharm Drug Dispos. 2004 Sep;25(6):243-52. doi: 10.1002/bdd.405.


Desloratadine is a non-sedating antihistamine recently approved for the treatment of seasonal allergic rhinitis. The major metabolite of desloratadine in human plasma and urine is the glucuronide conjugate of 3-hydroxydesloratadine. 3-Hydroxydesloratadine-glucuronide is also the major in vitro metabolite of 3-hydroxydesloratadine formed by incubation of 3-hydroxydesloratadine with human liver microsomes supplemented with uridine 5'-diphosphate-glucuronic acid (UDPGA). The metabolite structure was confirmed by LC-MS and LC-MS/MS. Out of ten recombinant human UDP-glucuronosyltransferases (UGTs), UGT1A1, UGT1A3, UGT1A8 and UGT2B15 exhibited catalytic activity with respect to the formation of 3-hydroxydesloratadine-glucuronide. Inhibition studies with known inhibitors of UGT (diclofenac, flunitrazepam and bilirubin) confirmed the involvement of UGT1A1, UGT1A3 and UGT2B15 in the formation of 3-hydroxydesloratadine-glucuronide. The results from this study demonstrated that the in vitro formation of 3-hydroxydesloratadine-glucuronide from 3-hydroxydesloratadine was mediated via UGT1A1, UGT1A3 and UGT2B15 in human liver.

Publication types

  • Comparative Study

MeSH terms

  • Bilirubin / pharmacology
  • Diclofenac / pharmacology
  • Enzyme Inhibitors / pharmacology
  • Flunitrazepam / pharmacology
  • Glucuronides / metabolism*
  • Glucuronosyltransferase / administration & dosage
  • Glucuronosyltransferase / antagonists & inhibitors
  • Glucuronosyltransferase / metabolism*
  • Histamine H1 Antagonists, Non-Sedating / metabolism*
  • Humans
  • In Vitro Techniques
  • Loratadine / analogs & derivatives*
  • Loratadine / metabolism*
  • Microsomes, Liver / enzymology
  • Microsomes, Liver / metabolism
  • Time Factors


  • Enzyme Inhibitors
  • Glucuronides
  • Histamine H1 Antagonists, Non-Sedating
  • Diclofenac
  • 3-hydroxydesloratadine
  • Flunitrazepam
  • Loratadine
  • UDP-glucuronosyltransferase, UGT1A3
  • UGT1A1 enzyme
  • Glucuronosyltransferase
  • UDP-glucuronosyltransferase 2B15, human
  • UDP-glucuronosyltransferase, UGT1A8
  • desloratadine
  • Bilirubin