Clozapine-induced transient white blood count disorders.
BACKGROUND
The aim of the study was to shed more light on the incidence and course of clozapine-induced transient white blood count (WBC) disorders.


METHODS
In an analysis of our clozapine drug monitoring program, we evaluated the data of 68 patients receiving clozapine for the first time. Incidence rates were calculated by actuarial life table analysis. The potential influence of sex, age, dose, and plasma level was evaluated using discriminant analysis.


RESULTS
Two patients developed progressive neutropenia, leading to agranulocytosis in one case. We also found the following transient hematologic dysfunctions: neutropenia (22.0%), eosinophilia (61.7%), and leukocytosis (40.9%). One patient showed chronic leukocytosis. Additionally, minor changes in the number of lymphocytes, monocytes, and basophilic granulocytes were detected in the study population.


CONCLUSIONS
Hematologic side effects are frequently induced by the atypical antipsychotic clozapine. Next to agranulocytosis, a progressive and potentially lethal hematologic adverse effect, most of the WBC disorders are transient and appear to be harmless.
Department of Psychiatry, Innsbruck University Clinics, Austria.
M
M
Hummer
M
M
Kurz
C
C
Barnas
A
A
Saria
W W
WW
Fleischhacker
D000206:Actuarial Analysis; D000328:Adult; D000380:Agranulocytosis / Q000139:chemically induced / Q000453:epidemiology; D001317:Austria / Q000453:epidemiology; D003024:Clozapine / Q000009:adverse effects* / Q000627:therapeutic use; D016903:Drug Monitoring; D004802:Eosinophilia / Q000139:chemically induced* / Q000453:epidemiology; D005260:Female; D006801:Humans; D015994:Incidence; D007964:Leukocytosis / Q000139:chemically induced* / Q000453:epidemiology; D008297:Male; D009503:Neutropenia / Q000139:chemically induced* / Q000453:epidemiology; D015995:Prevalence; D011446:Prospective Studies; D012559:Schizophrenia / Q000188:drug therapy*
D003024:Clozapine