Effect of cyproterone acetate on glucocorticoid secretion in patients treated for hirsutism

The effect of cyproterone acetate (CA) on adrenal glucocorticoid secretion was studied in 35 women with hirsutism. Patients were treated for 9 months with 100 mg CA orally 10 days each month, administered in reverse sequence with 21 days of a combination oral contraceptive containing 50 micrograms ethinyloestradiol and 2 mg CA. During treatment one patient had a mildly impaired plasma cortisol response to insulin-induced hypoglycaemia and 2 patients showed slight reduction of the plasma cortisol response to ACTH. Responses to metyrapone were normal in all patients tested. Overall, the mean response to these tests was significantly greater during CA treatment compared with pre-treatment measurements, probably due to effects of oestrogen on cortisol-binding globulin. In all patients urinary cortisol excretion remained normal and no patient demonstrated any features of steroid insufficiency. Thus it appears that CA has no untoward effect upon glucocorticoid secretion when given in high dosage for prolonged periods to hirsute women.