Efficacy and tolerability of clozapine in Japanese patients with treatment-resistant schizophrenia: Results from a 12-week, flexible dose study using raters masked to antipsychotic choice

Taro Kishi, Kiyoshi Fujita, Osamu Furukawa, Tatsuyo Suzuki, Masatsugu Moriwaki, Mari Nitta, Miho Hattori, Tomoko Tsunoka, Raja Chekuri, John M. Kane, Christoph U. Correll, Nakao Iwata

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11 Citations (Scopus)

Abstract

Japan approved clozapine for treatment-resistant schizophrenia in June 2009. The aim of this study was to evaluate clozapine's efficacy and tolerability in Japanese patients. A twelve-week, single-arm clinical trial of clozapine in treatment-resistant schizophrenia inpatients, was conducted under real-world conditions using raters masked for type of antipsychotic. Thirty-eight patients were recruited, with 33 (86.8%) completing the trial. At week 12, clozapine was associated with significant improvement in the Positive and Negative Syndrome Scale (PANSS) total (p<0.0001), PANSS positive (p<0.0001), negative (p=0.0055) and general subscale scores (p<0.0001). Significant improvements occurred in all PANSS scores by week 4, the first post-baseline psychopathology rating. Altogether, 50.0% of patients showed ≥20% reduction in PANSS total score, 20.6% had ≥30% reduction and 14.7% had >40% reduction. Eighteen patients (47.4%) were discharged before week 12. However, all patients experienced ≥1 adverse event. Two of 38 patients (5.2%) dropped out due to moderate leucopenia and one of them developed agranulocytosis after stopping clozapine. However, both patients recovered. Eight adverse events (hypersalivation, fatigue, sedation, constipation, insomnia, nausea/vomiting, chest pain and leucopenia) were observed in 34-79% of patients. These findings suggest that clozapine is beneficial in Japanese treatment-resistant schizophrenia patients. However, attention should be paid to patients' adverse events.

Original languageEnglish
Pages (from-to)200-207
Number of pages8
JournalAsian Journal of Psychiatry
Volume6
Issue number3
DOIs
Publication statusPublished - 06-2013

All Science Journal Classification (ASJC) codes

  • Psychology(all)
  • Psychiatry and Mental health

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