Which IV anesthetic can cause adrenal insufficiency?

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

Answer: (A)

Etomidate can cause adrenal insufficiency because it inhibits the adrenal enzyme 11β-hydroxylase (CYP11B1) in the cortex, blocking the final step of cortisol synthesis. This suppression of cortisol production can occur after a single induction dose and be more pronounced with repeated dosing or in critically ill patients who rely on endogenous cortisol to handle stress. Among common IV anesthetics, etomidate uniquely lowers cortisol production, whereas propofol and thiopental do not suppress adrenal function in clinically meaningful ways, and ketamine may even raise cortisol due to sympathetic activation. This makes etomidate the best answer when considering the risk of adrenal insufficiency.