Endocrine effects of CV 205-502, a new dopamine agonist, in hyperprolactinemic women

CV 205-502 (CV) is a potent dopaminergic compound which exerts a strong and sustained suppression of prolactin secretion in healthy volunteers. In a prospective double-blind, randomized, placebo-controlled trail, 12 hyperprolactinemic women (greater than or equal to 2000 mU/l), divided into 2 groups of 6 women each, were treated for 4 weeks. Combined pituitary challenge tests (GnRH, TRH, CRH and GHRH) were performed before and after treatment. The 6 CV-treated women (0.05 micrograms daily) showed approximately a 64% decrease of their initial prolactin serum concentrations after 4 weeks of capsule intake. Placebo-treated women showed no change in their prolactin serum level. After TRH administration, a blunted prolactin response was present in all women before treatment. After CV treatment a trend towards normalization of the prolactin response to TRH was seen, whereas the response pattern in the placebo group remained unaltered. The responses of GH, TSH, LH and ACTH to their releasing hormones and cortisol showed no significant changes after administration. FSH, however, showed a significant decrease in response to LH-RH, which could be explained by an increase in estradiol (E2) as ovarian function normalized in CV-treated women. In conclusion, CV shows strong dopamine agonistic properties in hyperprolactinemic women treated with 0.05 micrograms daily. The profile of this new quinoline compound, as judged from the pituitary challenge tests, does not differ from that of dopamine agonists of the ergoline type.