Etomidate 4600462 218235986 2008-06-09T19:40:55Z 63.71.65.210 /* Side effects */ {{Refimprove|date=April 2007}} {{drugbox | | IUPAC_name = ethyl&nbsp;3-[(1''R'')-1-phenylethyl]imidazole-<br>4-carboxylate | image = Etomidate skeletal.svg | image2 = Etomidate3d.png | CAS_number = 33125-97-2 | ATC_prefix = N01 | ATC_suffix = AX07 | PubChem = 667484 | DrugBank = APRD00965 | C = 14 |H = 16 |N = 2 |O = 2 | molecular_weight = 244.289 [[Gram|g]]/[[Mole (unit)|mol]] | protein_bound = 75% | metabolism = [[Ester]] [[hydrolysis]] | elimination_half-life = 75 [[Minutes|min]] | excretion = [[Kidney|Renal]] (85%) and biliary (15%) | pregnancy_category = D <small>([[United States|U.S.]])</small> | legal_UK = POM | routes_of_administration = [[Intravenous therapy|Intravenous]] }} '''Etomidate''' is a short acting [[intravenous]] anaesthetic agent used for the induction of [[general anaesthesia]] and for [[sedation]] for short procedures such as reduction of dislocated joints and [[cardioversion]]. It was discovered at [[Janssen Pharmaceutica]] in [[1964]]. ==Drug class== Etomidate, a hypnotic is a carboxylated [[imidazole]] derivative. Etomidate has [[anesthesia|anesthetic]] and [[amnesia|amnestic]] properties, but has no [[analgesia|analgesic]] properties. ==Uses== Etomidate is commonly used in the emergency setting as part of a [[rapid sequence induction]] to induce anesthesia or for [[conscious sedation]]. It is often used in this setting since it has a rapid onset of action and a low cardiovascular risk profile, and therefore is less likely to cause a significant drop in blood pressure than other induction agents. In the operating room with a stable patient, anesthesiologists may choose an alternative induction agent, such as [[propofol]], [[thiopental]] or [[methohexital]]. (see Side effects below). At the typical dose, anesthesia is induced for about 5–10 minutes even though the half-life of drug metabolism is approximately 75 minutes. This is because etomidate is redistributed from the plasma to other tissues. ==Dosage== The anaesthetic induction dose for adult humans is 0.3&nbsp;mg/kg intravenously, with a typical dose ranging from 20-40 mg. In common with all induction agents, etomidate causes loss of consciousness after one '''arm-brain circulation time'''. In very brief procedures such as cardioversion, a 10 mg dose may be used which may be repeated for effect. ==Metabolism== Etomidate is highly protein bound in [[blood plasma]] and is metabolised by hepatic and plasma [[esterase]]s to inactive products. It exhibits a [[Exponential decay|bi-exponential decline]], with a redistribution [[half-life]] of 2–5 minutes and an elimination half-life of 68–75 minutes. ==Side effects== The use of etomidate infusions for [[sedation]] of critically ill patients in [[intensive care unit]]s has been associated with increased mortality, which is due to suppression of [[steroid]] synthesis (both [[glucocorticoid]]s and [[mineralocorticoid]]s) in the [[adrenal cortex]]. This effect has been demonstrated after a single dose, and lasts about 24 hours. There is no evidence that a single induction dose of etomidate has any effect on morbidity or mortality. However, some sources advise giving a prophylactic dose of steroids (e.g. [[hydrocortisone]]) if etomidate is used. Seizure-like activity is occasionally seen with anesthetic induction. In the absence of concurrent EEG monitoring, it is difficult to ascribe this to cortical activity. [[Myoclonic]] movement originating at the spinal cord level is often a likely mechanism. Excitatory phenomena, and epileptiform movements and [[EEG]] activity may be observed during induction. Etomidate consistently increases the amplitude of somatosensory [[evoked potentials]] (in contrast to most anaesthetic agents). Etomidate in the propylene glycol formulation may produce [[Pain and nociception|pain]] on injection, a side effect which is less likely with the lipid formulation. There is a 30-fold difference between the [[effective dose]] and the [[lethal dose]] of etomidate, making it an extremely safe agent. Post operative vomiting is more common than with other induction agents. ==Formulation== Etomidate is usually presented as a clear colourless solution for injection containing 2&nbsp;mg/ml of etomidate in an aqueous solution of 35% [[propylene glycol]], although a [[lipid]] [[emulsion]] preparation (of equivalent strength) has also been introduced. Etomidate is presented as a [[racemic]] mixture, but only the D-[[isomer]] has pharmacological activity. {{General anesthetics}} [[Category:Anesthetics]] [[Category:Imidazoles]] [[de:Etomidat]] [[es:Etomidato]] [[fr:Étomidate]] [[it:Etomidate]] [[nl:Etomidaat]] [[pl:Etomidat]] [[pt:Etomidato]] [[ru:Этомидат]]