Etomidate is an imidazole derivative with short-acting sedative, hypnotic, and general anesthetic properties. Etomidate appears to have gamma-aminobutyric acid (GABA) like effects, mediated through GABA-A receptor. The action enhances the inhibitory effect of GABA on the central nervous system by causing chloride channel opening events which leads to membrane hyperpolarization.
This review focuses on the unique clinical and molecular pharmacology of etomidate. Among general anesthesia induction drugs, etomidate is the only imidazole, and it has the most favorable therapeutic index for single bolus administration. It also produces a unique toxicity among anesthetic drugs-- inhibition of adrenal steroid synthesis that far outlasts its hypnotic action and that may reduce survival of critically ill patients. The major molecular targets mediating anesthetic effects of etomidate in the central nervous system are specific γ-aminobutyric acid type A receptor subtypes. Amino acids forming etomidate binding sites have been identified in transmembrane domains of these proteins. Etomidate binding site structure models for the main enzyme mediating etomidate adrenotoxicity have also been developed. Based on this deepening understanding of molecular targets and actions, new etomidate derivatives are being investigated as potentially improved sedative-hypnotics or for use as highly selective inhibitors of adrenal steroid synthesis.
Forman, S. A. (2011). Clinical and molecular pharmacology of etomidate. Anesthesiology: The Journal of the American Society of Anesthesiologists, 114(3), 695-707.
Etomidate is an intravenous anesthetic agent released for clinical use in the United States in 1972. Its popularity in clinical practice is the result of its beneficial effects on intracerebral dynamics with limited effects on hemodynamic function. These properties have made it a safe and effective anesthetic induction agent in both adult and pediatric patients with altered myocardial performance, congenial heart disease, or hypovolemia. However, recent concern has been expressed regarding its effects on the endogenous production of corticosteroids and the impact of that effect on patient outcomes. The following manuscript reviews clinical reports regarding etomidate use in the pediatric population and discusses recent concerns regarding its effects on corticosteroid metabolism and the implications of such effects for clinical use.
Tobias, J. D. (2015). Etomidate in pediatric anesthesiology: Where are we now?. Saudi journal of anaesthesia, 9(4), 451.