Prolactin response in patients with schizophrenia treated with haloperidol, clozapine, risperidone and olanzapine

Background: The aim of our study was to investigate the prolactin (PRL) response after specific dopaminergic probe with sulpiride as well as serotonergic probe with clomipramine inpatients with schizophrenia treated with clozapine,olanzapine, risperidone, and haloperidol. Materials and methods: Male patients (N=44) diagnosed with schizophrenia according to DSMIV criteria were included in the study. Neuroendocrine assessment included the determination of PRL levels after specific dopaminergic probe with sulpiride and serotonergic probe with clomipramine. Results: Mean basal PRL levels differed significantly between groups (P<0.001). Post-hoc Scheffe test revealed significant difference between haloperidol group vs. all three other subgroups (clozapine, olanzapine, and risperidone). Furthermore, mean Delta PRL level after sulpiride (P<0.001) as well as after clomipramine (P<0.001) induction also differed significantly between patient sub groups. Conclusions: There is a difference in PRL response after dopaminergic and serotonergic probe in patients with schizophrenia treated with clozapine, olanzapine, risperidone and haloperidol. We hypothesize that this different response in neuroendocrine model might probably be due to neurotransmitter systems being occupied by different antipsychotic drugs.