Mechanism of transient adrenal insufficiency with megestrol acetate treatment of cachexia in children with cancer.

Megestrol acetate (MA) is used to stimulate appetite in children with cancer, but it can impair adrenal function and cause adrenal insufficiency. Three children with brain tumors were treated with MA to improve weight gain. Standard low-dose ACTH stimulation tests were performed on and off MA. All patients failed the low-dose ACTH stimulation while on MA and responded normally once off MA. The suppression of the adrenal axis was at the level of the hypothalamus/pituitary. Adrenal suppression can occur in patients treated with MA. Awareness of this possibility and the use of glucocorticoid stress coverage are advised.