The Incidence of Clozapine-Induced Leukopenia in Patients with Schizophrenia at Srinagarind Hospital
Sarin Maskasame MD*, Thawatchai Krisanaprakornkit MD*, Jiraporn Khiewyoo PhD**
Affiliation : * Department of Psychiatry, Faculty of Medicine, Khon Kaen University, Khon Kaen ** Department of Biostatistics and Demography, Faculty of Public Health Khon Kaen University, Khon Kaen
Objective : Define the incidence of clozapine-induced leukopenia, neutropenia, and agranulocytosis in patients
with schizophrenia at Srinagarind Hospital.
Materials and Methods : A descriptive study was done by retrospective reviews of the medical records of schizo-
phrenic outpatients at psychiatric clinic in Srinagarind Hospital who had received clozapine from January
1st, 2003 to December 31st, 2005. The demographic data, incidence rate, and incidence density of leukopenia,
neutropenia, and agranulocytosis were collected.
Results : One hundred and seventeen medical records were reviewed, 65 patients met the inclusion criteria.
One patient developed neutropenia. The incidence rate of neutropenia was 1.5% and the incidence density of
neutropenia was 0.01/year. No leukopenia or agranulocytosis was found in the present study. The complete
blood counts were not obtained regularly due to the problems of patient’s adherence and variations in
practice among the physicians.
Conclusion : Neutropenia is uncommon. No leukopenia and agranulocytosis were found. According to varia-
tions of incidence reports among different studies, the monitoring of white blood count should be continued.
Keywords : Clozapine, Leukopenia, Neutropenia, Agranulocytosis, Incidence rate, Incidence density
