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Pharmacopsychiatry 2003; 36(4): 156-160
DOI: 10.1055/s-2003-41201
Original Paper
© Georg Thieme Verlag Stuttgart · New York

Delirium During Clozapine Treatment: Incidence and Associated Risk Factors

F. Centorrino1 , M. J. Albert1 , G. Drago-Ferrante1 , A. E. Koukopoulos1 , J. M. Berry1 , R. J. Baldessarini1
  • 1Department of Psychiatry & Neuroscience Program, Harvard Medical School, Boston, MA, USA; Bipolar & Psychotic Disorders Program, McLean Division of Massachusetts General Hospital; and the International Consortium for Bipolar Disorder Research; Belmont, MA, USA
Supported, in part by NIH grant MH-47 370, an award from the Bruce J. Anderson Foundation, and by the McLean Private Donors Neuropsychopharmacology Research Fund (to RJB).
Further Information

Publication History

Received: 31.5.2002 Revised: 26.7.2002

Accepted: 26.9.2002

Publication Date:
07 August 2003 (online)

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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.

Key words

Anticholinergic - Clozapine - Delirium

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Dr. Franca Centorrino

Chief, Bipolar & Psychotic Disorders Clinic

McLean Hospital

115 Mill Street

Belmont, MA 02478

USA

Phone: 1 (617) 855 21 36

Fax: +1 (617) 855 20 00

Email: centorf@mcleanpo.mclean.org