title: Sex differences in the effect of four second-generation antipsychotics on QTc interval in patients with schizophrenia.
abstract: OBJECTIVE
  We examined sex differences in the effect of olanzapine (OLZ), risperidone (RIS), aripiprazole (ARP), or quetiapine (QTP) on mean corrected QT (QTc) intervals among 222 patients with schizophrenia.
  
  
  METHODS
  Subjects were patients with schizophrenia who were treated with either OLZ (n = 69), RIS (n = 60), ARP (n = 62), or QTP (n = 31). Electrocardiographic measurements were conducted, and the QT interval was corrected using Bazett's correction formula.
  
  
  RESULTS
  The mean QTc interval of the QTP group was significantly longer than that of the RIS group (p = 0.002) or ARP group (p = 0.029). The mean QTc interval of the OLZ group was also significantly longer than that of the RIS group (p = 0.006). In female participants, the difference in the mean QTc interval among the four second-generation antipsychotic (SGA) groups was statistically significant (p = 0.002), whereas in male patients, there was no significant difference in the mean QTc interval among the four SGA groups. Post hoc analyses showed that sex differences in QTc interval were observed only in OLZ treatment group (p = 0.007).
  
  
  CONCLUSIONS
  To our knowledge, this is the first study to demonstrate sex differences in the effect of four SGAs on the QTc interval.
authors.affiliation: Department of Psychiatry, Niigata University Graduate School of Medical and Dental Sciences, Chuo-ku, Niigata, Japan. yutaro@med.niigata-u.ac.jp
authors.forename: Yutaro
authors.initials: Y
authors.lastname: Suzuki
authors.forename: Takuro
authors.initials: T
authors.lastname: Sugai
authors.forename: Naoki
authors.initials: N
authors.lastname: Fukui
authors.forename: Junzo
authors.initials: J
authors.lastname: Watanabe
authors.forename: Shin
authors.initials: S
authors.lastname: Ono
authors.forename: Nobuto
authors.initials: N
authors.lastname: Tsuneyama
authors.forename: Mami
authors.initials: M
authors.lastname: Saito
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Someya
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D014150:Antipsychotic Agents / Q000009:adverse effects / Q000627:therapeutic use*; D000068180:Aripiprazole; D001569:Benzodiazepines / Q000009:adverse effects / Q000627:therapeutic use; D003987:Dibenzothiazepines / Q000009:adverse effects / Q000627:therapeutic use; D004562:Electrocardiography; D005260:Female; D006801:Humans; D008133:Long QT Syndrome / Q000139:chemically induced*; D008297:Male; D008875:Middle Aged; D000077152:Olanzapine; D010879:Piperazines / Q000009:adverse effects / Q000627:therapeutic use; D000069348:Quetiapine Fumarate; D015363:Quinolones / Q000009:adverse effects / Q000627:therapeutic use; D018967:Risperidone / Q000009:adverse effects / Q000627:therapeutic use; D012559:Schizophrenia / Q000188:drug therapy*; D012737:Sex Factors; D055815:Young Adult
chemical_list: D014150:Antipsychotic Agents; D003987:Dibenzothiazepines; D010879:Piperazines; D015363:Quinolones; D001569:Benzodiazepines; D000069348:Quetiapine Fumarate; D000068180:Aripiprazole; D018967:Risperidone; D000077152:Olanzapine