title: 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.
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.
authors: Department of Psychiatry, Fujita Health University School of Medicine, Toyoake, Aichi 470-1192, Japan. tarok@fujita-hu.ac.jp
authors: Taro
authors: T
authors: Kishi
authors: Kiyoshi
authors: K
authors: Fujita
authors: Osamu
authors: O
authors: Furukawa
authors: Tatsuyo
authors: T
authors: Suzuki
authors: Masatsugu
authors: M
authors: Moriwaki
authors: Mari
authors: M
authors: Nitta
authors: Miho
authors: M
authors: Hattori
authors: Tomoko
authors: T
authors: Tsunoka
authors: Raja
authors: R
authors: Chekuri
authors: John M
authors: JM
authors: Kane
authors: Christoph U
authors: CU
authors: Correll
authors: Nakao
authors: N
authors: Iwata
mesh_terms: D014150:Antipsychotic Agents / Q000008:administration & dosage* / Q000009:adverse effects; D003024:Clozapine / Q000008:administration & dosage* / Q000009:adverse effects; D004334:Drug Administration Schedule; D004351:Drug Resistance; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012559:Schizophrenia / Q000188:drug therapy*; D016896:Treatment Outcome
chemical_list: D014150:Antipsychotic Agents; D003024:Clozapine