Lack of effect of bromocriptine on ACTH levels in patients with bilateral adrenalectomy for pituitary-dependent Cushing's syndrome.

Bromocriptine lowers plasma ACTH levels in patients with pituitary-dependent Cushing's syndrome. It seemed possible that the drug would also be effective in patients who had been adrenalectomised for the disease. The effect of 5.0 mg of bromocriptine on plasma ACTH and prolactin levels in 13 patients, bilaterally adrenalectomised for pituitary-dependent Cushing's syndrome, was therefore studied. In only one patient was a fall in plasma ACTH observed. This may be of doubtful significance since marked spontaneous fluctuation in plasma ACTH levels were found in the five patients tested. Bromocriptine lowered the plasma prolactin in all of the patients, including two with hyperprolactinaemia.