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

Research output: Contribution to journalArticle

8 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 - 01-06-2013

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Clozapine
Antipsychotic Agents
Schizophrenia
Therapeutics
Leukopenia
Sialorrhea
Agranulocytosis
Sleep Initiation and Maintenance Disorders
Constipation
Chest Pain
Nausea
Vomiting
Fatigue
Inpatients
Japan
Clinical Trials

All Science Journal Classification (ASJC) codes

  • Psychology(all)
  • Psychiatry and Mental health

Cite this

Kishi, Taro ; Fujita, Kiyoshi ; Furukawa, Osamu ; Suzuki, Tatsuyo ; Moriwaki, Masatsugu ; Nitta, Mari ; Hattori, Miho ; Tsunoka, Tomoko ; Chekuri, Raja ; Kane, John M. ; Correll, Christoph U. ; Iwata, Nakao. / 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. In: Asian Journal of Psychiatry. 2013 ; Vol. 6, No. 3. pp. 200-207.
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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.",
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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. / Kishi, Taro; Fujita, Kiyoshi; Furukawa, Osamu; Suzuki, Tatsuyo; Moriwaki, Masatsugu; Nitta, Mari; Hattori, Miho; Tsunoka, Tomoko; Chekuri, Raja; Kane, John M.; Correll, Christoph U.; Iwata, Nakao.

In: Asian Journal of Psychiatry, Vol. 6, No. 3, 01.06.2013, p. 200-207.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Efficacy and tolerability of clozapine in Japanese patients with treatment-resistant schizophrenia

T2 - Results from a 12-week, flexible dose study using raters masked to antipsychotic choice

AU - Kishi, Taro

AU - Fujita, Kiyoshi

AU - Furukawa, Osamu

AU - Suzuki, Tatsuyo

AU - Moriwaki, Masatsugu

AU - Nitta, Mari

AU - Hattori, Miho

AU - Tsunoka, Tomoko

AU - Chekuri, Raja

AU - Kane, John M.

AU - Correll, Christoph U.

AU - Iwata, Nakao

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Y1 - 2013/6/1

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