Suppression of ectopic adrenocorticotropin secretion by the long-acting somatostatin analog octreotide

The long-acting somatostatin analog (octreotide) was administered to a 37-yr-old woman with the ectopic ACTH syndrome. The patient had diffuse metastatic spread of a nonpituitary tumor, presumably of pancreatic origin, and severe and rapidly progressive hypercortisolism with extreme myopathy, hypokalemia, and diabetes mellitus. Plasma ACTH and lipotropin levels and 24-h urinary cortisol excretion were greatly elevated [218 pg/mL (48 pmol/L), 1340 pg/mL (220 pmol/L), and up to 830 micrograms/24 h (2290 nmol/day), respectively]. Urinary cortisol excretion decreased to normal within 3 days after the initiation of octreotide therapy (150, 300, and 600 micrograms/day), and plasma ACTH and lipotropin levels also decreased. Urinary cortisol excretion remained normal for 2 months during chronic octreotide therapy, and her general condition improved dramatically. The only side-effect was a slight increase in the number of bowel movements. Tumor progression, however, was not controlled, and she eventually died of hepatic insufficiency. These data indicate that octreotide can be a highly effective treatment for patients with the ectopic ACTH syndrome.