title: Delirium during clozapine treatment: incidence and associated risk factors.
abstract: BACKGROUND
  Incidence and risk factors for delirium during clozapine treatment require further clarification.
  
  
  METHODS
  We used computerized pharmacy records to identify all adult psychiatric inpatients treated with clozapine (1995-96), reviewed their medical records to score incidence and severity of delirium, and tested associations with potential risk factors.
  
  
  RESULTS
  Subjects (n = 139) were 72 women and 67 men, aged 40.8 +/- 12.1 years, hospitalized for 24.9 +/- 23.3 days, and given clozapine, gradually increased to an average daily dose of 282 +/- 203 mg (3.45 +/- 2.45 mg/kg) for 18.9 +/- 16.4 days. Delirium was diagnosed in 14 (10.1 % incidence, or 1.48 cases/person-years of exposure); 71.4 % of cases were moderate or severe. Associated factors were co-treatment with other centrally antimuscarinic agents, poor clinical outcome, older age, and longer hospitalization (by 17.5 days, increasing cost); sex, diagnosis or medical co-morbidity, and daily clozapine dose, which fell with age, were unrelated.
  
  
  CONCLUSIONS
  Delirium was found in 10 % of clozapine-treated inpatients, particularly in older patients exposed to other central anticholinergics. Delirium was inconsistently recognized clinically in milder cases and was associated with increased length-of-stay and higher costs, and inferior clinical outcome.
authors.affiliation: Department of Psychiatry & Neuroscience Program, Harvard Medical School, Boston, MA, USA. centorf@mcleanpo.mclean.org
authors.forename: F
authors.initials: F
authors.lastname: Centorrino
authors.forename: M J
authors.initials: MJ
authors.lastname: Albert
authors.forename: G
authors.initials: G
authors.lastname: Drago-Ferrante
authors.forename: A E
authors.initials: AE
authors.lastname: Koukopoulos
authors.forename: J M
authors.initials: JM
authors.lastname: Berry
authors.forename: R J
authors.initials: RJ
authors.lastname: Baldessarini
mesh_terms: D000328:Adult; D014150:Antipsychotic Agents / Q000009:adverse effects*; D003024:Clozapine / Q000009:adverse effects*; D003693:Delirium / Q000139:chemically induced*; D005260:Female; D006778:Hospitals, Psychiatric; D006801:Humans; D008297:Male; D015999:Multivariate Analysis; D011618:Psychotic Disorders / Q000188:drug therapy; D012189:Retrospective Studies
chemical_list: D014150:Antipsychotic Agents; D003024:Clozapine