Normalization of Potassium Despite 11-Deoxycorticosterone Rise During Etomidate Therapy in Adrenocortical Carcinoma.

Adrenocortical carcinoma (ACC) is a rare malignancy often associated with disorganized steroid synthesis, leading to variable clinical phenotypes. Etomidate, an imidazole derivative, is a potent inhibitor of adrenal cytochrome P450-dependent enzymes, particularly 11β-hydroxylase (CYP11B1). Subhypnotic doses of etomidate are effective in reducing serum cortisol in patients with severe Cushing syndrome, a common manifestation in ACC. However, the effects of etomidate on other adrenal hormones in ACC remain poorly understood. In this report, we measured 13 steroid hormones before and after etomidate infusion using liquid chromatography-tandem mass spectrometry in a patient with ACC. Etomidate administration led to marked suppression of cortisol and aldosterone, while 11-deoxycorticosterone levels increased substantially. Interestingly, despite the elevated 11-deoxycorticosterone, serum potassium normalized, highlighting a complex interplay among mineralocorticoid precursors and active hormones in maintaining electrolyte balance.