Haematological side effects of clozapine: patient characteristics.
OBJECTIVE
To determine the prevalence of neutropenia and agranulocytosis in patients taking clozapine since its introduction into New Zealand in April 1988.


METHODS
Data was collected by Sandoz Pharma (NZ) Ltd on blood counts from all patients prescribed clozapine as part of its worldwide monitoring programme for this drug. The data was analysed by one of the authors (AEC). Case histories to illustrate the principal ways in which falls in white cells present.


RESULTS
A total of 693 patients have been exposed to clozapine between April 1988 and June 1995. The cumulative agranulocytosis rate for the first 7 years of use was 1.15%. There were eight cases of agranulocytosis and no deaths. An additional 14 cases neutropenia were reported (2.02%).


CONCLUSIONS
The agranulocytosis and neutropenia rates reported from New Zealand compare favourably with those from larger overseas studies though the exposed patient base is modest.
Miller
P R
PR
Forensic Psychiatric Service, Healthlink South, Sunnyside Hospital, Christchurch.
Cutten
A E
AE
D000293:Adolescent; D000328:Adult; D016907:Adverse Drug Reaction Reporting Systems; D000368:Aged; D000380:Agranulocytosis / Q000139:chemically induced*; D014150:Antipsychotic Agents / Q000009:adverse effects*; D003024:Clozapine / Q000009:adverse effects*; D016903:Drug Monitoring; D005260:Female; D006801:Humans; D007958:Leukocyte Count; D008297:Male; D008875:Middle Aged; D009503:Neutropenia / Q000139:chemically induced*; D009520:New Zealand; D015995:Prevalence; D012559:Schizophrenia / Q000188:drug therapy*
D014150:Antipsychotic Agents; D003024:Clozapine