title: Effect of the cytochrome P450 2D6*10 allele on risperidone metabolism in Japanese psychiatric patients.
abstract: OBJECTIVE
  The sum of the serum levels of risperidone (RIS) and 9-hydroxyrisperidone (9-OH-RIS), which is the active moiety serum level, could be important for estimating the clinical effects of RIS. However, there have been no consistent results reported about the relationship between cytochrome P450 (CYP) 2D6*10 allele and plasma 9-OH-RIS or active moiety levels. We investigated the effect of the number of CYP2D6*10 alleles on steady-state plasma RIS, 9-OH-RIS, and active moiety levels in Japanese patients.
  
  
  METHODS
  Steady-state plasma RIS, 9-OH-RIS, and active moiety levels were measured in 64 patients treated with an average dosage of 4.6 mg/day.
  
  
  RESULTS
  The number of CYP2D6*10 alleles significantly affected dose-corrected plasma RIS levels (p = 0.001), and the median concentrations in ng/ml/mg were 0.94 (0 allele) vs. 1.73 (1 allele) vs. 3.05 (2 alleles). The number of CYP2D6*10 alleles did not affect plasma 9-OH-RIS or active moiety levels.
  
  
  CONCLUSIONS
  The present study shows that the number of CYP2D6*10 alleles affected plasma RIS levels but not plasma 9-OH-RIS and plasma active moiety levels. Because the plasma active moiety levels can influence antipsychotic effects or side effects, the genetic screening of the CYP2D6*10 allele for RIS in Asian populations may not be clinically important.
authors: Department of Psychiatry, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan.
authors: Yutaro
authors: Y
authors: Suzuki
authors: Naoki
authors: N
authors: Fukui
authors: Nobuto
authors: N
authors: Tsuneyama
authors: Junzo
authors: J
authors: Watanabe
authors: Shin
authors: S
authors: Ono
authors: Takuro
authors: T
authors: Sugai
authors: Mami
authors: M
authors: Saito
authors: Yoshimasa
authors: Y
authors: Inoue
authors: Toshiyuki
authors: T
authors: Someya
mesh_terms: D000328:Adult; D000483:Alleles; D014150:Antipsychotic Agents / Q000378:metabolism / Q000493:pharmacokinetics*; D019389:Cytochrome P-450 CYP2D6 / Q000235:genetics*; D005260:Female; D006801:Humans; D007555:Isoxazoles / Q000097:blood; D007564:Japan; D008297:Male; D008875:Middle Aged; D000068882:Paliperidone Palmitate; D011618:Psychotic Disorders / Q000188:drug therapy; D011743:Pyrimidines / Q000097:blood; D018967:Risperidone / Q000378:metabolism / Q000493:pharmacokinetics*; D012559:Schizophrenia / Q000188:drug therapy; D055815:Young Adult
chemical_list: D014150:Antipsychotic Agents; D007555:Isoxazoles; D011743:Pyrimidines; D019389:Cytochrome P-450 CYP2D6; D018967:Risperidone; D000068882:Paliperidone Palmitate