Association of antipsychotic use with raised eosinophil count

The current study aimed to assess the possibility of an association between first and second generation antipsychotic medication and raised eosinophil count. A total of 22 in-patients at the psychiatric unit of the University General Hospital ‘Attikon’, a tertiary hospital, were included in the present study. Patients had received antipsychotic monotherapy and did not have any co-morbidities or require additional treatments. Patients were monitored weekly and their eosinophil count was assessed. One-way ANOVA and summary measures analysis were applied to study the effect of time and medication type on the absolute eosinophil concentration (or relative percentage) for each patient. The differences in mean eosinophil concentrations or relative percentage by patient and time were also assessed. An increase in the absolute concentration and the relative percentage of eosinophils over time was observed in patients receiving Olanzapine, Haloperidol and Aripiprazole. However, there was no difference between individual medications. In conclusion, antipsychotics may be associated with increased eosinophil count over time; however, larger studies involving more patients and a longer follow-up are required to reach a definitive conclusion.