Time dependency and reversibility of the effects of exclusive cyproterone acetate therapy on pituitary adrenal function in hirsute women.
The effects of cyproterone acetate (CA) administration on the pituitary-adrenal axis were studied in 30 hirsute females. The patients were treated continuously with a daily dose of 100 mg of CA for a maximal period of 12 months. Insulin-induced hypoglycaemia and ACTH infusion were performed on pre-treatment conditions and after 1, 4, 6 and 12 months of CA treatment. From a clinical point of view, a dramatic improvement of hirsutism was evident after 6 months of therapy. The most commonly reported side effects were amenorrhoea and transient uterine haemorrhage. Apart from asthenia, no symptoms of adrenal insufficiency were noticed. No changes in pituitary-adrenal secretion were observed during the first 4 months of therapy. From the 6th month, a reduction in basal as well as stimulated cortisol levels was seen. Simultaneously, an enhanced ACTH response to hypoglycaemia was observed. Both effects became more pronounced after 1 year of treatment. There were no significant changes in ACTH basal values. Six months after discontinuation of the drug, adrenocortical reserve improved but was still slightly reduced when compared to pre-treatment range at that time. These findings suggest a time-dependent negative effect of CA on adrenal steroidogenesis which shows a reversible character 6 months after antiandrogen withdrawal. Therefore, steroid cover should be considered for intercurrent illness in patients treated for longer than 6 months with this therapeutic regime.