title: Relevance of CYP2D6 variability in first-episode schizophrenia patients treated with risperidone.
abstract: OBJECTIVE
  The objective of this prospective, naturalistic study, conducted in first-episode psychosis patients from a Central-European population, was to assess the utility of Cytochrome P-450 2D6 (CYP2D6) genotype testing under normal clinical setting.
  
  
  METHODS
  A total of 35 patients diagnosed for the first time with schizophrenia or acute schizophrenia-like psychotic disorder and treated with risperidone were enrolled in the study. These patients underwent sequentiation of the CYP2D6 gene and evaluations of symptoms and severity of adverse effects using the PANSS and UKU scales, respectively. Doses of antipsychotics and other co-medication were monitored as well. In statistical analysis, Fisher's exact test was used to compare ratios and the Wilcoxon rank-sum test was used in the comparison of continual variables.
  
  
  RESULTS
  PM patients showed a significantly lower reduction in psychotic symptoms and a greater severity of psychotic symptoms following risperidone treatment and higher doses of antipsychotics not metabolized by CYP2D6, which were used as co-medication.
  
  
  CONCLUSIONS
  Based on these results, patients with the PM genotype experiencing first-episode schizophrenia don't appear to be optimal recipients of risperidone treatment. However, as the main limitation of this study was the relatively small sample-size, replication with a larger scale study is needed to confirm these findings.
authors.affiliation: Behavioral and Social Neuroscience Research Group, Central European Institute of Technology (CEITEC), Masaryk University, Czech Republic. rbartecek@gmail.com
authors.forename: Richard
authors.initials: R
authors.lastname: Barteček
authors.forename: Jan
authors.initials: J
authors.lastname: Juřica
authors.forename: Jana
authors.initials: J
authors.lastname: Zrůstová
authors.forename: Tomáš
authors.initials: T
authors.lastname: Kašpárek
authors.forename: Eva
authors.initials: E
authors.lastname: Pindurová
authors.forename: Alexandra
authors.initials: A
authors.lastname: Žourková
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000483:Alleles; D014150:Antipsychotic Agents / Q000009:adverse effects / Q000627:therapeutic use*; D019389:Cytochrome P-450 CYP2D6 / Q000235:genetics*; D005260:Female; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011569:Psychiatric Status Rating Scales / Q000706:statistics & numerical data; D011618:Psychotic Disorders / Q000188:drug therapy / Q000235:genetics; D018967:Risperidone / Q000009:adverse effects / Q000627:therapeutic use*; D012559:Schizophrenia / Q000175:diagnosis / Q000188:drug therapy* / Q000235:genetics*
chemical_list: D014150:Antipsychotic Agents; D019389:Cytochrome P-450 CYP2D6; D018967:Risperidone