Dose requirement and prolactin elevation of antipsychotics in male and female patients with schizophrenia or related psychoses.

AIMS: The aim of this study was to investigate the prolactin (PRL) secretion and the growth hormone (GH)-insulin-like growth factor I (IGF-I) axis in relation to gender and side-effects and dose of antipsychotic drugs during long-term treatment.

METHODS

Forty-seven patients (21 men and 26 women), diagnosed with schizophrenia or related psychoses according to the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) criteria and treated with different classical antipsychotics, were studied. Prolactin, GH and IGF-I were measured, as well as the serum concentration of the antipsychotics. In addition, body mass index (BMI) was calculated.

RESULTS

The median daily, as well as the median body weight, adjusted daily dose of antipsychotic drugs was twofold higher in male compared with female patients. Antipsychotic-induced hyperprolactinaemia was more frequent and occurred at a lower daily dose of antipsychotics in women. Irrespective of sex, more than half of the patients had elevated BMI. Two patients had a slight increment in IGF-I levels, whereas the GH concentration, as assessed on a single occasion, was normal in all patients.

CONCLUSIONS

Patients on long-term antipsychotic therapy, with doses adjusted according to therapeutic efficiency, exhibited hyperprolactinaemia and elevated BMI, but no obvious influence on the GH-IGF-I axis. Furthermore, it appeared that the males required twice the dose of antipsychotic compared with females.