Metabolic and endocrine abnormalities secondary to hyperprolactinemia, such as hypogonadism and hyperandrogenicity, may be involved in the excessive body weight gain induced by antipsychotic drugs in women. The present study was conducted in healthy premenopausal women, in order to detect an endocrine imbalance secondary to antipsychotic drug administration, which, if sustained in the long term, might be involved in the development of obesity. After a control menstrual cycle, sulpiride (200 mg/day) or placebo was nonblindly administered for 28 days; blood lipids and the serum levels of the following hormones which are involved in body weight regulation were assessed at days 3, 10, 20 and 26 of the cycle: prolactin (PRL), 17-beta estradiol (E2), progesterone (P4), follicle stimulating hormone (FSH), luteinizing hormone (LH), free testosterone (T5), dehydroepiandrosterone sulfate (DHEAS), cortisol, tyrotropic hormone (TSH), tetraiodothyroxine (T4), and the areas under the insulin and glucose tolerance curve. During sulpiride administration, the following changes were observed when compared to placebo administration: PRL levels were significantly increased; E2 levels were significantly reduced at days 10 and 20; P4 levels were significantly reduced at day 20, and the area under the glucose tolerance curve was significantly increased. The other variables were not significantly affected. The body weight gain was higher during sulpiride than during placebo administration, but it did not reach statistical significance, perhaps because the period of treatment was too short. The decrease in the serum levels of E2 during sulpiride administration is probably secondary to hyperprolactinemia. It affects the E2/T5 ratio in the direction of increasing the androgenic activity, as observed in women with well-established obesity. This effect, along with a genetic predisposition, increased appetite, hypoactivity and ignorance of proper dietary habits, may explain the excessive weight gain and obesity observed in women during chronic treatment with sulpiride and other antipsychotic agents.
