The effect of cyproterone acetate on adrenal cortical function in children with precocious puberty

8 children with precocious puberty were treated with cyproterone acetate (CPA). During treatment there were no definite clinical signs of depressed adrenocortical function. The plasma cortisol concentrations were grossly depressed and the diurnal cortisol rhythm was abolished. Two months after discontinuation of CPA treatment the adrenocortical function had greatly improved. The lysin-vasopressin stimulation test revealed in one child a normal, in another child an exaggerated ACTH response during CPA therapy. Fasting plasma ACTH concentrations were elevated compared with normal controls, but they were very low compared with patients with Addison's disease. The results suggest that CPA has a twofold effect leading to adrenocortical insufficiency: i.e., inhibition of cortisol secretion by the adrenals themselves and inhibition of ACTH secretion at the hypothalamopitiuitary level.