Serum neuroleptic and prolactin levels in schizophrenic patients and clinical response

Following a drug-free placebo period lasting at least 1 week, 10 female and 11 male newly hospitalized schizophrenic patients received chlorpromazine (CPZ) 200 mg/day for 1 week and 400 mg/day the following week. Serum CPZ equivalent (CPZ-E) levels were measured at the end of each week of CPZ treatment with a radioreceptor assay. Chlorpromazine-E levels were significantly higher in females than males, but this finding could be accounted for by differences in body weight. Serum prolactin (PRL) levels were also higher in females than males. After differences in serum CPZ-E level were adjusted for, females still had significantly higher serum PRL levels than males. Serum PRL levels increased between the first and second treatment weeks in females but not in males. Correlations between serum CPZ-E and PRL levels were higher among males than females. Significant improvement for the patient group as a whole was observed during the 2 weeks of treatment, with a strong trend for females to improve more than males. Clinical outcome at this initial period was not predicted by either serum PRL levels or serum CPZ-E levels.