ETOMIDATE
History
Etomidate (Amidate, Hypnomidate) was synthesized[574]
in 1964 and was introduced into clinical practice[575]
in 1972. Its properties include hemodynamic stability, minimal respiratory depression,
cerebral protection, and pharmacokinetics enabling rapid recovery after either a
single dose
or a continuous infusion. In animals, etomidate also provides a wider margin of
safety (median effective dose/median lethal dose [ED50
/LD50
])
than thiopental does (26.4 versus 4.6).[576]
These
beneficial properties led to the widespread use of etomidate for induction, for maintenance
of anesthesia, and for prolonged sedation in critically ill patients. Anesthesiologists'
enthusiasm for etomidate, however, was tempered by reports that the drug can cause
temporary inhibition of steroid synthesis after both single doses and infusions.
[338]
[577]
[578]
This effect, combined with other minor disadvantages (e.g., pain on injection, superficial
thrombophlebitis, myoclonus, and a relatively high incidence of nausea and vomiting)
led to several editorials[579]
[580]
[581]
questioning the role of etomidate in modern
anesthetic practice. Use of the drug waned significantly after these editorials,
but it has expanded because of rediscovery of etomidate's beneficial physiologic
profile combined with a lack of any new reports describing clinically significant
adrenocortical suppression after an induction dose or brief infusion.
