title: Prevalence of desloratadine poor metabolizer phenotype in healthy Jordanian males.
abstract: OBJECTIVE
  To study the prevalence of desloratadine slow metabolizer phenotype among a group of healthy Jordanian male volunteers.
  
  
  METHODS
  A total of 62 healthy Jordanian male volunteers were included in this study. A single 5 mg desloratadine oral tablet was given and blood samples were taken to determine the desloratadine and 3-hydroxydesloratadine (3-OH-desloratadine) concentrations using a specific liquid chromatography-mass spectrometric method (LC/MS/MS). The determination of pharmacokinetic parameters of all the individuals was determined by using Kinetica® program version 4.1. Poor metabolizers or slow metabolizers of desloratadine were determined as individuals having a 3-OH-desloratadine to desloratadine exposure ratio lower than 10% or a desloratadine half-life ≥ 50 h.
  
  
  RESULTS
  Among the 62 volunteers who participated in the study there were only two volunteers who were labeled as desloratadine slow metabolizers, giving a prevalence of 3.2%. The maximum plasma concentrations (C(max)) were similar in the extensive and slow metabolizers groups but a longer time (t(max)) was needed to achieve this concentration in one of the volunteers who was a desloratadine slow metabolizer.
  
  
  CONCLUSIONS
  The incidence of the poor metabolizer phenotype of desloratadine in the Jordanian population studied is similar to certain ethnic groups (e.g. Asian, Caucasians and Hispanic); however, it is lower than other populations (e.g. American Indians and Black).
authors.affiliation: Faculty of Pharmacy, University of Jordan, Amman 11942, Jordan. nhakooz@ju.edu.jo
authors.forename: Nancy
authors.initials: N
authors.lastname: Hakooz
authors.forename: Isam I
authors.initials: II
authors.lastname: Salem
mesh_terms: D000293:Adolescent; D000328:Adult; D019540:Area Under Curve; D002851:Chromatography, High Pressure Liquid; D039563:Histamine H1 Antagonists, Non-Sedating / Q000097:blood / Q000493:pharmacokinetics*; D006801:Humans; D007597:Jordan; D017336:Loratadine / Q000031:analogs & derivatives* / Q000097:blood / Q000493:pharmacokinetics; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D053719:Tandem Mass Spectrometry; D055815:Young Adult
chemical_list: D039563:Histamine H1 Antagonists, Non-Sedating; C482880:3-hydroxydesloratadine; D017336:Loratadine; C121345:desloratadine