Perazine – the atypical side of an conventional antipsychotic

*These authors contributed equally to this paper ·AGATE=Arbeitsgemeinschaft Arzneimitteltherapie bei psychiatrischen Erkrankungen Since the introduction of clozapine more recently introduced antipsychotic agents claim to be „atypical“, assuring therapeutic response while producing few or no extrapyramidal motor side effects (EPS). The present study addresses the issue whether the „typical“ perazine is different in producing EPS from other antipsychotics (clozapine, olanzapine, risperidone, flupentixol). Prescription data of antipsychotics were analyzed for 4,199 inpatients with psychotic diseases (ICD 10: F20– F25). Comedication with the anticholinergic biperiden was used as an index of EPS. Numbers-needed-to-harm for EPS compared to clozapine were calculated to obtain risk estimates for olanzapine, risperidone, flupentixol and perazine. Olanzapine and perazine show statistically equal EPS-rates over the whole dosage spectrum. EPS-rates for perazine are significant lower than for flupentixol and risperidone when daily doses of the latter exceed 5mg/d. Clozapine by far has the lowest risk of EPS of all antipsychotics assessed. Perazine therefore is no less „atypical“ than newer antipsychotics like olanzapine or risperidone.