indication

Used in the induction of general anesthesia.

pharmacology

Etomidate is a non-barbiturate hypnotic that acts at the level of the reticular-activating system to produce anesthesia. Etomidate is an imidazole compound that appears to depress CNS function via GABA. Duration of action is intermediate between thiopental and methohexital, and recovery from a single dose is rapid with little residual depression. Like the barbiturates and propofol, etomidate is does not induce analgesia. Etomidate induces unconsciousness within one circulation time. Recovery is rapid as a result of extensive redistribution and rapid metabolism.

mechanism of action

Etomidate binds at a distinct binding site associated with a Cl^- ionopore at the GABA_A receptor, increasing the duration of time for which the Cl^- ionopore is open. The post-synaptic inhibitory effect of GABA in the thalamus is, therefore, prolonged.

toxicity

Undesirable side effects of etomidate that may limit its use include pain on injection, myoclonus and adrenocortical suppression lasting 4-6 hours following an induction dose.

biotransformation

Hepatic. Metabolized rapidly by ester hydrolysis to inactive metabolites.

half life

75 minutes.

route of elimination

Approximately 75% of the administered dose is excreted in the urine during the first day after injection.