title: Long-term sustained benefits of clozapine treatment in refractory early onset schizophrenia: a retrospective study in Korean children and adolescents.
abstract: OBJECTIVE
  Treatment resistance in early onset schizophrenia (EOS) is one of the most challenging problems in child and adolescent psychiatry. We retrospectively examined the therapeutic dosage, clinical response, and side effect profiles of long-term clozapine treatment in Korean children and adolescents with refractory EOS or very early onset schizophrenia (VEOS).
  
  
  METHODS
  26 refractory patients treated with clozapine for more than 1 year were analyzed. Efficacy was determined by comparing hospitalization rate and duration, before and after clozapine treatment. Tolerability was assessed through review of documented adverse events.
  
  
  RESULTS
  A significant reduction in hospital days per year was observed in 25 (96.2%) patients after clozapine treatment compared to before clozapine. Long-term benefit of the treatment was supported by a further reduction of the hospitalization rate in 14 patients treated with clozapine for more than 3 years. Neutropenia developed in 26.9% patients at 1 year and there was no agranulocytosis. Overall, eight male patients (8/12, 66.7%) and one female patient (1/14, 7%) developed neutropenia and out of the nine patients, seven patients were maintained and two patients were successfully rechallenged on clozapine.
  
  
  CONCLUSIONS
  These findings suggest that long-term clozapine treatment may effectively reduce the amount of time Asian patients with refractory EOS or VEOS spend in the hospital. However careful monitoring of adverse events is required.
authors.affiliation: Division of Child, Adolescent Psychiatry, Department of Psychiatry and Institute of Human Behavioral Medicine, Seoul National University Hospital, Korea.
authors.forename: Yeni
authors.initials: Y
authors.lastname: Kim
authors.forename: Boong-Nyun
authors.initials: BN
authors.lastname: Kim
authors.forename: Soo-Churl
authors.initials: SC
authors.lastname: Cho
authors.forename: Jae-Won
authors.initials: JW
authors.lastname: Kim
authors.forename: Min-Sup
authors.initials: MS
authors.lastname: Shin
mesh_terms: D000293:Adolescent; D017668:Age of Onset; D014150:Antipsychotic Agents / Q000008:administration & dosage* / Q000009:adverse effects / Q000627:therapeutic use*; D044466:Asian People; D003024:Clozapine / Q000008:administration & dosage* / Q000009:adverse effects / Q000627:therapeutic use*; D004305:Dose-Response Relationship, Drug; D004351:Drug Resistance; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D007723:Korea / Q000453:epidemiology; D007902:Length of Stay; D008297:Male; D009503:Neutropenia / Q000097:blood / Q000139:chemically induced / Q000453:epidemiology; D011569:Psychiatric Status Rating Scales; D012189:Retrospective Studies; D012559:Schizophrenia / Q000188:drug therapy*; D012565:Schizophrenic Psychology; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D014150:Antipsychotic Agents; D003024:Clozapine