The aim of the study was an analysis of prolactin concentration in the course of antipsychotic treatment in Polish patients participating in EUFEST study.

Seventy-eight patients with the first episode of schizophrenia were studied, randomly allocated to the treatment with low dose haloperidol (n=23), amisulpride (n=21), olanzapine (n=22), quetiapine (n=11) or ziprasidone (n=1), for the period of 12 months. Prolactin concentration was assessed at baseline and after 6 and 12 months of treatment. Hyperprolactinemia was defined as prolactin concentration >18 ng/ml in males and >25 ng/ml in females.

At baseline, the mean prolactin concentration was 56,5 ng/ml and hyperprolactinemia was observed in 86% of patients, slightly more than in the whole EUFEST group (71%). Prolactin concentration was similar in drug-naïve as in non-drug-naïve patients. After 6 month of treatment, hyperprolactinemia was found in 67% of patients, lowest in haloperidol (29%) and highest in amisulpride group (93%). After 12 months, hyperprolactinemia was observed in 56% of patients, lowest in quetiapine (36%) and highest in amisulpride group (80%).

Hyperprolactinemia was found in a majority of patients with the first episode of schizophrenia, including drug-naïve patients. In the course of one-year antipsychotic treatment, in patients receiving amisulpride, the hyperprolactinemia has been maintained at the initial high level while in remaining groups, a reduction by about 50% of the number of patients having hypeprolactinemia at baseline was observed. We suggest that an abnormality of stress system, could contribute to hyperprolactinemia independent of antipsychotic treatment in the first episode schizophrenic patients.