[Effect of high single doses of bromocriptine in schizophrenic patients with elevated serum prolactin levels and extrapyramidal side effects associated with neuroleptic treatment (author's transl)].

The purpose of the present study was to investigate the effect of bromocriptine in single doses of 20 and 30 mg on the unwanted effects most frequently caused by neuroleptics: elevated prolactin levels and extrapyramidal disturbances. 111 chronic schizophrenics were included in the investigations, 58 of them being treated with haloperidol and 53 with chlorpromazine. It was found that a single dose of 30 mg bromocriptine brought about a statistically significant decrease in the prolactin levels of patients treated with haloperidol but produced no more than a downward tendency in patients receiving chlorpromazine (the initial prolactin levels of both groups of patients were equal.) The effect of bromocriptine on EPS disturbances was more marked in the chlorpromazine group, but side effects such as nausea and agitation also occurred more frequently in this group. These results show that there is no correlation between the reduction in prolactin levels produced by bromocriptine and an improvement in unwanted EPS effects. This supports the hypothesis that the effect of neuroleptics on the prolactin secreting cells of the anterior pituitary and their effect on the EPS are mediated by different sets of receptors.