Abstract
Purpose: To investigate the kinetics of adrenocorticotropin (ACTH) following oral metyrapone
administration and describe differences between ACTH-deficient and non-ACTH-deficient
subjects.
Methods: Patients from a tertiary endocrine center at a University Hospital in Munich, Germany,
were tested for secondary adrenal insufficiency in a regular patient care setting.
Metyrapone (Metopirone, HRA Pharma, France) was administered with a dosage of 40 mg/kg
bodyweight at 8 a.m. Consecutive levels of ACTH were determined at 0, 60, 120, 180,
and 240 min. Patients were categorized according to their need of glucocorticoid substitution
in the follow-up phase.
Results: A significant rise in ACTH concentration compared to basal values was found at 60
and 120 min following oral metyrapone administration. ACTH concentrations at 60 and
120 min predicted patients without need for glucocorticoid substitution. ACTH concentrations
determined later had no additional benefit.
Conclusion: In contrast to previous reports, we found a significant rise in ACTH concentration
as soon as one hour after oral metyrapone administration. ACTH values seem to estimate
the pituitary corticotrophic function when correlating results to the further clinical
course of subjects. Further studies are needed to investigate this finding as a potential
basis for a ACTH-based metyrapone short test protocol.
Key words
hypopituitarism - metyrapone - ACTH
