title: Losartan hydroxylation phenotype in an Ecuadorian population: influence of CYP2C9 genetic polymorphism, habits and gender.
abstract: OBJECTIVE
  To describe for the first time CYP2C9 hydroxylation phenotype with CYP2C9 genotypes in a Hispanic (Ecuadorian) population using losartan; and the relevance of gender, tobacco, ethanol and caffeine consumption on the enzyme hydroxylation capacity.
  
  
  METHODS
  Ecuadorian healthy volunteers (n = 194) received a single oral dose of 25 mg losartan. Losartan metabolic ratio was defined as losartan:E3174 concentration. CYP2C9 alleles *2, *3, *4, *5 and *6 were analyzed.
  
  
  RESULTS
  No phenotypically poor metabolizers were found. The metabolic ratio (mean ± standard deviation) was higher (p < 0.05) in CYP2C9*1/*3 carriers (12.4 ± 13.8; n = 6) versus CYP2C9*1/*1 (4.9 ± 7.0; n = 167), as well as in females versus males (6.72 ± 9.72 and 3.76 ± 4.48, respectively; p < 0.05). Only the following genotypes, CYP2C9*1/*1, CYP2C9*1/*2 and CYP2C9*1/*3, were found with a frequency of 86.1%, 10.8% and 3.1%, respectively.
  
  
  CONCLUSIONS
  Despite the mean metabolic ratio being higher in this population than in others previously studied across genotypes, no poor metabolizers, either phenotypically or genotypically, were found.
authors.affiliation: CICAB Centro de Investigación Clínica, University of Extremadura, SES Servicio Extremeño de Salud, Hospital Universitario Infanta Cristina, 06080 Badajoz, Spain.
authors.forename: Pedro
authors.initials: P
authors.lastname: Dorado
authors.forename: Leonardo J
authors.initials: LJ
authors.lastname: Beltrán
authors.forename: Esther
authors.initials: E
authors.lastname: Machín
authors.forename: Eva M
authors.initials: EM
authors.lastname: Peñas-Lledó
authors.forename: Enrique
authors.initials: E
authors.lastname: Terán
authors.forename: Adrián
authors.initials: A
authors.lastname: Llerena
mesh_terms: D000328:Adult; D000428:Alcohol Drinking / Q000235:genetics / Q000378:metabolism; D001189:Aryl Hydrocarbon Hydroxylases / Q000235:genetics* / Q000378:metabolism; D002110:Caffeine / Q000008:administration & dosage; D003069:Coffee; D065729:Cytochrome P-450 CYP2C9; D005260:Female; D005838:Genotype; D006184:Habits; D006630:Hispanic or Latino / Q000235:genetics*; D006801:Humans; D006900:Hydroxylation; D019808:Losartan / Q000378:metabolism*; D008297:Male; D010641:Phenotype; D011110:Polymorphism, Genetic; D012737:Sex Factors; D012907:Smoking / Q000235:genetics / Q000378:metabolism; D055815:Young Adult
chemical_list: D003069:Coffee; D002110:Caffeine; C450260:CYP2C9 protein, human; D065729:Cytochrome P-450 CYP2C9; D001189:Aryl Hydrocarbon Hydroxylases; D019808:Losartan