Which agent is associated with adrenal suppression?

Which agent is associated with adrenal suppression?

• A. Thiopental
• B. Diazepam
• C. Etomidate
• D. Propofol

Answer: (C)

Etomidate is associated with adrenal suppression due to its inhibition of the enzyme 11β-hydroxylase in the adrenal cortex. This enzyme is necessary for converting 11-deoxycortisol to cortisol (and 11-deoxycorticosterone to corticosterone). By blocking this step, etomidate acutely lowers cortisol production, blunting the body's stress response to anesthesia. A single dose can transiently reduce cortisol levels, and prolonged or continuous use can cause more lasting suppression, which is particularly concerning in critically ill patients who rely on endogenous cortisol for hemodynamic stability and immune response. The other commonly used induction agents—thiopental, diazepam, and propofol—do not inhibit 11β-hydroxylase and thus do not cause adrenal suppression through this mechanism (though they have other hemodynamic and physiologic effects).

Etomidate is associated with adrenal suppression due to its inhibition of the enzyme 11β-hydroxylase in the adrenal cortex. This enzyme is necessary for converting 11-deoxycortisol to cortisol (and 11-deoxycorticosterone to corticosterone). By blocking this step, etomidate acutely lowers cortisol production, blunting the body's stress response to anesthesia. A single dose can transiently reduce cortisol levels, and prolonged or continuous use can cause more lasting suppression, which is particularly concerning in critically ill patients who rely on endogenous cortisol for hemodynamic stability and immune response. The other commonly used induction agents—thiopental, diazepam, and propofol—do not inhibit 11β-hydroxylase and thus do not cause adrenal suppression through this mechanism (though they have other hemodynamic and physiologic effects).