THE EFFECT OF NAFARELIN ON HUMAN PLASMA ADRENOCORTICOTROPIC HORMONE AND CORTISOL CONCENTRATIONS

This study assessed the effects on plasma adrenocorticotrophic hormone (ACTH) and cortisol concentrations of 3 months' treatment with intran asal nafarelin 200 mug b.d. in 11 women (aged 26-43 years) for the tre atment of endometriosis (n = 9), fibroids (n = 1) and pre-menstrual sy ndrome (n = 1). Serial blood samples were taken over 5 h, before and a fter nafarelin administration on the first day of treatment, and after 1 and 3 months' treatment. Control samples were taken before and afte r intranasal placebo administration on the day before nafarelin was co mmenced. The area under the curve (AUC) for mean ACTH concentrations a t each time point from 0 to 240 min was calculated. There were no stat istically significant changes in total secretion of either ACTH or cor tisol. There was a transient rise in ACTH 30-60 min after nafarelin ad ministration on the first day of treatment in seven out of 11 women. T he rise did not exceed the normal range. Seven women with ovarian supp ression (oestradiol concentration <175 pmol/l by day 28) had consisten tly lower mean ACTH concentrations at all time points than the four re maining women who had oestradiol concentrations 222 - 880 pmol/l by da y 28. Cortisol concentrations were unaffected by nafarelin. We conclud e from the results of this study that 3 months' treatment with nafarel in has no effects on adrenal function, as assessed by ACTH and cortiso l concentrations.