Pituitary-Adrenal Suppression and Cushing's Syndrome After Intermittent Dexamethasone Therapy

SUMMARY

Six patients have been treated with high-dosage dexamethasone every 48 hr for 3 to 29 weeks. Pituitary-adrenal function, as measured by the urinary 17-ketosteroid and 17-hydroxysteroid response to intravenous adrenocorticotrophic hormone during therapy, was significantly depressed in all subjects. Significant metabolic side effects occurred in four of the patients, with two instances of pitting edema. Clinical response was excellent in four patients with sarcoidosis, fair in a patient with the nephrotic syndrome, and poor in a patient with reticulum cell sarcoma.

The results of this study with dexamethasone differ from recorded experiences with alternate-day prednisone, which produces few side effects and minimal pituitary-adrenal suppression.

Dexamethasone appears to have more potent and prolonged pituitary-adrenal suppressive properties when compared with a 1:6.6 ratio of prednisone. Although the number of cases treated with alternate-day dexamethasone is small, experience to date indicates that pituitary-adrenal suppression and glucocorticoid side effects should be expected at the dose and duration of dexamethasone therapy administered in the present study.