Nα-Acetyl-L-tryptophan amide

Etomidate is a hypnotic agent that is used for the induction of anesthesia. It produces its effect by acting as a positive allosteric modulator on the γ-aminobutyric acid type A receptor and thus enhancing the effect of the inhibitory neurotransmitter γ-aminobutyric acid. Etomidate stands out among other anesthetic agents by having a remarkably stable cardiorespiratory profile, producing no cardiovascular or respiratory depression. However, etomidate suppresses the adrenocortical axis by the inhibition of the enzyme 11β-hydroxylase. This makes the drug unsuitable for administration by a prolonged infusion. It also makes the drug unsuitable for administration to critically ill patients. Etomidate has relatively large volumes of distributions and is rapidly metabolized by hepatic esterases into an inactive carboxylic acid through hydrolyzation. Because of the decrease in popularity of etomidate, few modern extensive pharmacokinetic or pharmacodynamic studies exist. Over the last decade, several analogs of etomidate have been developed, with the aim of retaining its stable cardiorespiratory profile, whilst eliminating its suppressive effect on the adrenocortical axis. One of these molecules, ABP-700, was studied in extensive phase I clinical trials. These found that ABP-700 is characterized by small volumes of distribution and rapid clearance. ABP-700 is metabolized similarly to etomidate, by hydrolyzation into an inactive carboxylic acid. Furthermore, ABP-700 showed a rapid onset and offset of clinical effect. One side effect observed with both etomidate and ABP-700 is the occurrence of involuntary muscle movements. The origin of these movements is unclear and warrants further research.

Purpose: Etomidate and ketamine are hemodynamically stable induction agents often used to sedate critically ill patients during emergency endotracheal intubation. In 2015, quality improvement data from our hospital suggested a survival benefit at Day 7 from avoidance of etomidate in critically ill patients during emergency intubation. In this clinical trial, we hypothesized that randomization to ketamine instead of etomidate would be associated with Day 7 survival after emergency endotracheal intubation. Methods: A prospective, randomized, open-label, parallel assignment, single-center clinical trial performed by an anesthesiology-based Airway Team under emergent circumstances at one high-volume medical center in the United States. 801 critically ill patients requiring emergency intubation were randomly assigned 1:1 by computer-generated, pre-randomized sealed envelopes to receive etomidate (0.2-0.3 mg/kg, n = 400) or ketamine (1-2 mg/kg, n = 401) for sedation prior to intubation. The pre-specified primary endpoint of the trial was Day 7 survival. Secondary endpoints included Day 28 survival. Results: Of the 801 enrolled patients, 396 were analyzed in the etomidate arm, and 395 in the ketamine arm. Day 7 survival was significantly lower in the etomidate arm than in the ketamine arm (77.3% versus 85.1%, difference - 7.8, 95% confidence interval - 13, - 2.4, p = 0.005). Day 28 survival rates for the two groups were not significantly different (etomidate 64.1%, ketamine 66.8%, difference - 2.7, 95% confidence interval - 9.3, 3.9, p = 0.294). Conclusion: While the primary outcome of Day 7 survival was greater in patients randomized to ketamine, there was no significant difference in survival by Day 28.

Purpose: Etomidate causes adrenal insufficiency. Yet in critically ill patients, it is controversial whether it increases mortality rates above that of comparator anesthetic induction agents. We postulated that etomidate would increase relative mortality rates correspondingly to the severity of illness as defined by SAPS or APACHE scores. Materials and methods: A literature search was performed on Pub Med, SCOPUS, and Cochrane Reviews for human studies, regardless of language, between 1983 and February 2020. The search strategy used keywords, "etomidate," "adrenal insufficiency," "glucocorticoid," and "intensive care." Both authors reviewed electronic data search titles, abstracts and extracted data, which were checked by the other reviewer. Primary outcome was 28-day survival. Secondary outcome was adrenal insufficiency. Results: There were 29 trials of etomidate versus comparators in 8584 patients. Etomidate was associated with adrenal insufficiency (risk ratio (rr) = 1·54, 95% CI; 1·42, 1·67, p < 0.001) and increased overall relative mortality rates (rr = 1.09, CI;1.04,1.16, p = 0.001). Meta-regression showed that with etomidate there was a continuous progressive relative risk of mortality associated with increasing severity of illness (predefined in each article by standard critical illness scores). In those patients who had a predicted mortality rate > the median for this analysis (predicted mortality 44%) the relative mortality rate (rr) = 1.20, Ci;1.12,1.29, p < 0.001, the absolute risk difference (rd) = 0.08, CI;0.05,0.11, p < 0.0001 and the number needed to harm (1/rd) was 12.5. In those with a calculated predicted mortality <44% there was no increase in relative mortality rate. Conclusions: Whereas etomidate causes adrenal insufficiency, it was not shown to increase mortality in many analyzed here in ICU settings. However, etomidate associated relative mortality rates increased progressively and correlated with the severity of critical illness scores. Intensivists should anticipate the need for glucocorticoid supplementation after etomidate in those with severe critical illness and in those with acute deterioration of vital signs.