Introduction: Megestrol acetate (MA) is a progestational agent used for palliation of breast and endometrial cancer. The drug promotes weight gain via appetite stimulation. This property has led to widespread use in patients with wasting illnesses. Increasing numbers of reports suggest glucocorticoid activity.
Objective: Unrecognized adrenal suppression may result from MA use. This is the first study to examine the prevalence of adrenal suppression in hospitalized patients treated with MA.
Subjects and design: This is a cross-sectional study of hospitalized patients receiving MA compared to control subjects. Morning cortisol levels, endocrine signs and symptoms, and duration of MA therapy were evaluated in 28 hospitalized medical patients treated with MA, and 21 control patients admitted to the same hospital service during the study period.
Results: Median cortisol levels were significantly lower in patients using MA vs controls (160 vs 386 nmol/l, p=0.003). Forty-three percent of subjects on MA demonstrated morning cortisol levels below the normal range (138-690 nmol/l), compared with 10% of controls (p=0.013). Ninety-three percent of subjects taking MA had morning cortisol levels below the level that excludes adrenal insufficiency in hospitalized patients (497 nmol/l) vs 71% of controls (p=0.06).
Conclusions: MA use is associated with significant adrenal suppression in acutely ill individuals. This should alert physicians to the possibility of adrenal insufficiency and the need to assess for signs or symptoms of adrenal insufficiency, and mandates a low threshold for testing adrenal function in hospitalized patients taking MA.