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Deng C, Liu J, Zhang W. Structural Modification in Anesthetic Drug Development for Prodrugs and Soft Drugs. Front Pharmacol 2022; 13:923353. [PMID: 35847008 PMCID: PMC9283706 DOI: 10.3389/fphar.2022.923353] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Accepted: 06/01/2022] [Indexed: 11/18/2022] Open
Abstract
Among the advancements in drug structural modifications, the increased focus on drug metabolic and pharmacokinetic properties in the anesthetic drug design process has led to significant developments. Drug metabolism also plays a key role in optimizing the pharmacokinetics, pharmacodynamics, and safety of drug molecules. Thus, in the field of anesthesiology, the applications of pharmacokinetic strategies are discussed in the context of sedatives, analgesics, and muscle relaxants. In this review, we summarize two approaches for structural optimization to develop anesthetic drugs, by designing prodrugs and soft drugs. Drugs that both failed and succeeded during the developmental stage are highlighted to illustrate how drug metabolism and pharmacokinetic optimization strategies may help improve their physical and chemical properties.
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Affiliation(s)
- Chaoyi Deng
- Department of Anesthesiology, West China Hospital, Sichuan University, Chengdu, China
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, West China Hospital, Sichuan University, Chengdu, China
| | - Jin Liu
- Department of Anesthesiology, West China Hospital, Sichuan University, Chengdu, China
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, West China Hospital, Sichuan University, Chengdu, China
| | - Wensheng Zhang
- Department of Anesthesiology, West China Hospital, Sichuan University, Chengdu, China
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, West China Hospital, Sichuan University, Chengdu, China
- *Correspondence: Wensheng Zhang,
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Valk BI, Struys MMRF. Etomidate and its Analogs: A Review of Pharmacokinetics and Pharmacodynamics. Clin Pharmacokinet 2021; 60:1253-1269. [PMID: 34060021 PMCID: PMC8505283 DOI: 10.1007/s40262-021-01038-6] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/11/2021] [Indexed: 01/09/2023]
Abstract
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.
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Affiliation(s)
- Beatrijs I Valk
- Department of Anesthesiology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9713 GZ, Groningen, The Netherlands
| | - Michel M R F Struys
- Department of Anesthesiology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9713 GZ, Groningen, The Netherlands.
- Department of Basic and Applied Medical Sciences, Ghent University, Ghent, Belgium.
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Zhang YJ, Deng C, Yang J, Gong D, Kang Y, Liu J, Zhang W. Preclinical Pharmacokinetics Study of a Novel Intravenous Anesthetic ET-26 Hydrochloride. Curr Drug Metab 2020; 20:1073-1081. [PMID: 31870260 DOI: 10.2174/1389200221666191223105504] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Revised: 11/27/2019] [Accepted: 12/01/2019] [Indexed: 02/08/2023]
Abstract
BACKGROUND ET-26 hydrochloride is a novel intravenous anesthetic, approved for clinical trials, that produces a desirable sedative-hypnotic effect with stable myocardial performance and mild adrenocortical suppression in rats and beagle dogs. The objective of this study was to assess the absorption, distribution, metabolism, and excretion of ET-26 hydrochloride. METHODS Hepatocytes from human, monkey, dog, rat, and mouse were used to determine the metabolites of ET-26 hydrochloride. Distribution and excretion were assessed in rats and pharmacokinetic studies were performed in beagle dogs. RESULTS The metabolic pathway and proposed structure of metabolites were fully assessed resulting from the biotransformation reactions of hydrolysis, dehydrogenation, demethylation and glucuronic acid conjugation. The main distribution of the drug was in fat (15067 ± 801 ng/ml) and liver (13647 ± 1126 ng/ml), and the kidney was the primary excretion route (4.47%-11.94%). The Cmax after injection with 1.045 mg/kg, 2.09 mg/kg, and 4.18 mg/kg was 1476.5 ± 138.9 ng/ml, 2846.1 ± 223.3 ng/ml, and 6233.3 ± 238.9 ng/ml, respectively. The t1/2 of the drug was similar across dose groups at 74.8 ± 10.8 min to 81.4 ± 4.2 min. The AUC0-t values were 30208.1 ± 2026.5 min*ng/ml, 62712.8 ± 1808.3 min*ng/ml, and 130465.2 ± 7457.4 min*ng/ml, respectively. CONCLUSION The metabolic pathway and the proposed structure of metabolites for ET-26 hydrochloride were fully assessed. The majority of distribution for ET-26 hydrochloride occurs in the fat and liver, while the primary route of excretion for ET-26 hydrochloride is through the kidney. In dogs, pharmacokinetic features of ET-26 hydrochloride had a linear relationship with dosage.
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Affiliation(s)
- Yu Jun Zhang
- Department of Anesthesiology, Laboratory of Anesthesia and Critical Care Medicine, Translational Neuroscience Center, West China Hospital, Sichuan University, Chengdu, Sichuan, China.,National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, West China Hospital, Sichuan University, Chengdu, China
| | - ChaoYi Deng
- Department of Anesthesiology, Laboratory of Anesthesia and Critical Care Medicine, Translational Neuroscience Center, West China Hospital, Sichuan University, Chengdu, Sichuan, China.,National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, West China Hospital, Sichuan University, Chengdu, China
| | - Jun Yang
- Department of Anesthesiology, Laboratory of Anesthesia and Critical Care Medicine, Translational Neuroscience Center, West China Hospital, Sichuan University, Chengdu, Sichuan, China.,National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, West China Hospital, Sichuan University, Chengdu, China
| | - DeYing Gong
- Department of Anesthesiology, Laboratory of Anesthesia and Critical Care Medicine, Translational Neuroscience Center, West China Hospital, Sichuan University, Chengdu, Sichuan, China.,National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, West China Hospital, Sichuan University, Chengdu, China
| | - Yi Kang
- Department of Anesthesiology, Laboratory of Anesthesia and Critical Care Medicine, Translational Neuroscience Center, West China Hospital, Sichuan University, Chengdu, Sichuan, China.,National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, West China Hospital, Sichuan University, Chengdu, China
| | - Jin Liu
- Department of Anesthesiology, Laboratory of Anesthesia and Critical Care Medicine, Translational Neuroscience Center, West China Hospital, Sichuan University, Chengdu, Sichuan, China.,National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, West China Hospital, Sichuan University, Chengdu, China
| | - WenSheng Zhang
- Department of Anesthesiology, Laboratory of Anesthesia and Critical Care Medicine, Translational Neuroscience Center, West China Hospital, Sichuan University, Chengdu, Sichuan, China.,National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, West China Hospital, Sichuan University, Chengdu, China
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Zhang Y, Deng C, Gong D, Kang Y, Liu J, Zhang W. Preclinical safety evaluation of ET-26 hydrochloride, a novel intravenous anesthetic agent, in beagle dogs. J Appl Toxicol 2019; 40:679-690. [PMID: 31867768 DOI: 10.1002/jat.3936] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
ET-26 hydrochloride (ET-26HCl) is a novel etomidate analogue, approved for clinical trials, which has an effective sedative-hypnotic effect, a stable myocardial performance, and milder adrenocortical suppression than etomidate in rats and beagle dogs. Additionally, ET-26HCl showed similar hemodynamic stability as etomidate in the rat uncontrolled hemorrhagic shock model. Furthermore, ET-26HCl, in the rat lipopolysaccharide-induced sepsis model, was found to have a higher survival rate, a lower inflammatory reaction, and less organ injury. In the present study, we measured the potential adverse effects of ET-26HCl in beagle dogs in accordance with the Guidance on single- and repeated-dose toxicity published by the China Food and Drug Administration. In toxicity studies, single and repeated (14 days) intravenous doses of up to 16 mg/kg were well tolerated, with only pharmacologically related clinical signs seen in both studies. Thus, the no-observed-adverse-effect level (NOAEL) of ET-26HCl was found at 16 mg/kg/day. Toxicokinetic examination demonstrated that ET-26HCl showed a dose-dependent increase to exposure, no gender difference, and no evidence of accumulation. These results provide useful information for guiding a phase I clinical trial of ET-26HCl in healthy volunteers.
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Affiliation(s)
- YuJun Zhang
- Department of Anesthesiology, Laboratory of Anesthesia and Critical Care Medicine, Translational Neuroscience Center, West China Hospital, Sichuan University, Chengdu, Sichuan, China.,National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, West China Hospital, Sichuan University, Chengdu, China
| | - ChaoYi Deng
- Department of Anesthesiology, Laboratory of Anesthesia and Critical Care Medicine, Translational Neuroscience Center, West China Hospital, Sichuan University, Chengdu, Sichuan, China.,National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, West China Hospital, Sichuan University, Chengdu, China
| | - DeYing Gong
- Department of Anesthesiology, Laboratory of Anesthesia and Critical Care Medicine, Translational Neuroscience Center, West China Hospital, Sichuan University, Chengdu, Sichuan, China.,National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, West China Hospital, Sichuan University, Chengdu, China
| | - Yi Kang
- Department of Anesthesiology, Laboratory of Anesthesia and Critical Care Medicine, Translational Neuroscience Center, West China Hospital, Sichuan University, Chengdu, Sichuan, China.,National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, West China Hospital, Sichuan University, Chengdu, China
| | - Jin Liu
- Department of Anesthesiology, Laboratory of Anesthesia and Critical Care Medicine, Translational Neuroscience Center, West China Hospital, Sichuan University, Chengdu, Sichuan, China.,National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, West China Hospital, Sichuan University, Chengdu, China
| | - WenSheng Zhang
- Department of Anesthesiology, Laboratory of Anesthesia and Critical Care Medicine, Translational Neuroscience Center, West China Hospital, Sichuan University, Chengdu, Sichuan, China.,National-Local Joint Engineering Research Center of Translational Medicine of Anesthesiology, West China Hospital, Sichuan University, Chengdu, China
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Antkowiak B, Rammes G. GABA(A) receptor-targeted drug development -New perspectives in perioperative anesthesia. Expert Opin Drug Discov 2019; 14:683-699. [DOI: 10.1080/17460441.2019.1599356] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Bernd Antkowiak
- Department of Anesthesiology and Intensive Care, Experimental Anesthesiology Section, Eberhard-Karls-University,
Tübingen, Germany
- Department of Anaesthesiology and Intensive Care, Experimental Anaesthesiology Section, Werner Reichardt Center for Integrative Neuroscience, Tübingen,
Germany
| | - Gerhard Rammes
- University Hospital rechts der Isar, Department of Anesthesiology, München,
Germany
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Valk B, Absalom A, Meyer P, Meier S, den Daas I, van Amsterdam K, Campagna J, Sweeney S, Struys M. Safety and clinical effect of i.v. infusion of cyclopropyl-methoxycarbonyl etomidate (ABP-700), a soft analogue of etomidate, in healthy subjects. Br J Anaesth 2018; 120:1401-1411. [DOI: 10.1016/j.bja.2018.01.038] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2017] [Revised: 01/15/2018] [Accepted: 02/19/2018] [Indexed: 11/25/2022] Open
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Abstract
GABA (γ-aminobutyric acid) receptors, of which there are two types, are involved in inhibitory synapses within the central nervous system. The GABAA receptor (GABAAR) has a central role in modern anesthesia and sedation practice, which is evident from the high proportion of agents that target the GABAAR. Many GABAAR agonists are used in anesthesia practice and sedation, including propofol, etomidate, methohexital, thiopental, isoflurane, sevoflurane, and desflurane. There are advantages and disadvantages to each GABAAR agonist currently in clinical use. With increasing knowledge regarding the pharmacology of GABAAR agonists, however, newer sedative agents have been developed which employ 'soft pharmacology', a term used to describe the pharmacology of agents whereby their chemical configuration allows rapid metabolism into inactive metabolites after the desired therapeutic effect(s) has occurred. These newer 'soft' GABAAR agonists may well approach ideal sedative agents, as they can offer well-controlled, titratable activity and ultrashort action. This review provides an overview of the role that GABAAR agonists currently play in sedation and anesthesia, in addition to discussing the future role of novel GABAAR agonists in anesthesia and sedation.
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A Phase 1, Single-center, Double-blind, Placebo-controlled Study in Healthy Subjects to Assess the Safety, Tolerability, Clinical Effects, and Pharmacokinetics–Pharmacodynamics of Intravenous Cyclopropyl-methoxycarbonylmetomidate (ABP-700) after a Single Ascending Bolus Dose. Anesthesiology 2017; 127:20-35. [DOI: 10.1097/aln.0000000000001662] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Abstract
Background
Cyclopropyl-methoxycarbonylmetomidate (ABP-700) is a new “soft” etomidate analog. The primary objectives of this first-in-human study were to describe the safety and efficacy of ABP-700 and to determine its maximum tolerated dose. Secondary objectives were to characterize the pharmacokinetics of ABP-700 and its primary metabolite (cyclopropyl-methoxycarbonyl acid), to assess the clinical effects of ABP-700, and to investigate the dose–response and pharmacokinetic/pharmacodynamic relationships.
Methods
Sixty subjects were divided into 10 cohorts and received an increasing, single bolus of either ABP-700 or placebo. Safety was assessed by clinical laboratory evaluations, infusion-site reactions, continuous monitoring of vital signs, physical examination, adverse event monitoring, and adrenocorticotropic hormone stimulation testing. Clinical effects were assessed with modified observer’s assessment of alertness/sedation and Bispectral Index monitoring. Pharmacokinetic parameters were calculated.
Results
Stopping criteria were met at 1.00 mg/kg dose. No serious adverse events were reported. Adverse events were dose-dependent and comprised involuntary muscle movement, tachycardia, and ventilatory effects. Adrenocorticotropic hormone stimulation evoked a physiologic cortisol response in all subjects, no different from placebo. Pharmacokinetics were dose-proportional. A three-compartment pharmacokinetic model described the data well. A rapid onset of anesthesia/sedation after bolus administration and also a rapid recovery were observed. A quantitative concentration–effect relationship was described for the modified observer’s assessment of alertness/sedation and Bispectral Index.
Conclusions
This first-in-human study of ABP-700 shows that ABP-700 was safe and well tolerated after single-bolus injections up to 1.00 mg/kg. Bolus doses of 0.25 and 0.35 mg/kg were found to provide the most beneficial clinical effect versus side-effect profile.
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A Novel Strategy to Reverse General Anesthesia by Scavenging with the Acyclic Cucurbit[n]uril-type Molecular Container Calabadion 2. Anesthesiology 2017; 125:333-45. [PMID: 27341276 DOI: 10.1097/aln.0000000000001199] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Calabadion 2 is a new drug-encapsulating agent. In this study, the authors aim to assess its utility as an agent to reverse general anesthesia with etomidate and ketamine and facilitate recovery. METHODS To evaluate the effect of calabadion 2 on anesthesia recovery, the authors studied the response of rats to calabadion 2 after continuous and bolus intravenous etomidate or ketamine and bolus intramuscular ketamine administration. The authors measured electroencephalographic predictors of depth of anesthesia (burst suppression ratio and total electroencephalographic power), functional mobility impairment, blood pressure, and toxicity. RESULTS Calabadion 2 dose-dependently reverses the effects of ketamine and etomidate on electroencephalographic predictors of depth of anesthesia, as well as drug-induced hypotension, and shortens the time to recovery of righting reflex and functional mobility. Calabadion 2 displayed low cytotoxicity in MTS-3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium-based cell viability and adenylate kinase release cell necrosis assays, did not inhibit the human ether-à-go-go-related channel, and was not mutagenic (Ames test). On the basis of maximum tolerable dose and acceleration of righting reflex recovery, the authors calculated the therapeutic index of calabadion 2 in recovery as 16:1 (95% CI, 10 to 26:1) for the reversal of ketamine and 3:1 (95% CI, 2 to 5:1) for the reversal of etomidate. CONCLUSIONS Calabadion 2 reverses etomidate and ketamine anesthesia in rats by chemical encapsulation at nontoxic concentrations.
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Tanious MK, Beutler SS, Kaye AD, Urman RD. New Hypnotic Drug Development and Pharmacologic Considerations for Clinical Anesthesia. Anesthesiol Clin 2017; 35:e95-e113. [PMID: 28526163 DOI: 10.1016/j.anclin.2017.01.017] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Since the public demonstration of ether as a novel, viable anesthetic for surgery in 1846, the field of anesthesia has continually sought the ideal anesthetic-rapid onset, potent sedation-hypnosis with a high therapeutic ratio of toxic dose to minimally effective dose, predictable clearance to inactive metabolites, and minimal side effects. This article aims to review current progress of novel induction agent development and provide an update on the most promising drugs poised to enter clinical practice. In addition, the authors describe trends in novel agent development, implications for health care costs, and implications for perioperative care.
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Affiliation(s)
- Mariah Kincaid Tanious
- Department of Anesthesiology, Perioperative and Pain Medicine, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA 02115, USA
| | - Sascha S Beutler
- Department of Anesthesiology, Perioperative and Pain Medicine, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA 02115, USA
| | - Alan D Kaye
- Department of Anesthesiology and Pain Medicine, Louisiana State University School of Medicine, LSU Health Science Center, 1542 Tulane Avenue, Room 659, New Orleans, LA 70112, USA
| | - Richard D Urman
- Department of Anesthesiology, Perioperative and Pain Medicine, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA 02115, USA.
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Yang J, Kang Y, Wang B, Yang L, Liu J, Zhang W. Metabolite-inactive etomidate analogues alleviating suppression on adrenal function in Beagle dogs. Eur J Pharm Sci 2017; 99:343-349. [PMID: 28057551 DOI: 10.1016/j.ejps.2016.12.041] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Revised: 12/23/2016] [Accepted: 12/31/2016] [Indexed: 02/05/2023]
Abstract
Owing to rapid generation in body, the metabolites of etomidate softdrug are able to accumulate in either the brain or periphery and subsequently affect the recovery from anaesthesia or cause corticosteroid suppression. This study was designed to investigate the ability of two etomidate analogues (ET-26, ET-42) with inactive metabolites to provide anaesthesia with lesser corticosteroid suppression. The 50% effective dose (ED50) of ET-26, ET-42, Etomidate, MOC-ET (an etomidate softdrug) and CPMM (an improved etomidate softdrug) required to induce anaesthesia intravenously in Beagle dogs were 1.44mg/kg, 0.72mg/kg, 0.43mg/kg 23.12mg/kg and 0.59mg/kg, respectively. After adrenocorticotropic hormone (ACTH) stimulation, the serum concentrations of cortisol and corticosterone in the ET-26, ET-42 and CPMM groups were similar to those of controls, and significantly higher than those of the etomidate and MOC-etomidate groups (P<0.05). Furthermore, no significant differences in serum concentrations of cortisol and corticosterone after ACTH-stimulation between ET-26, ET-42, CPMM, and blank control groups were observed. In this study, anaesthetic potencies of ET-26 (ED50=1.44mg/kg) and ET-42 (ED50=0.72mg/kg) were determined. Both analogues can significantly reduce the corticosteroid suppression in vivo. Metabolite-inactive etomidate derivatives with slow metabolism might provide a novel strategy to improve Etomidate associated corticosteroid suppression.
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Affiliation(s)
- Jun Yang
- Laboratory of Anesthesia and Critical Care Medicine, Translational Neuroscience Centre, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, PR China
| | - Yi Kang
- Laboratory of Anesthesia and Critical Care Medicine, Translational Neuroscience Centre, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, PR China
| | - Bin Wang
- Laboratory of Anesthesia and Critical Care Medicine, Translational Neuroscience Centre, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, PR China
| | - Linghui Yang
- Laboratory of Anesthesia and Critical Care Medicine, Translational Neuroscience Centre, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, PR China
| | - Jin Liu
- Laboratory of Anesthesia and Critical Care Medicine, Translational Neuroscience Centre, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, PR China; Department of Anesthesiology, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, PR China
| | - Wensheng Zhang
- Laboratory of Anesthesia and Critical Care Medicine, Translational Neuroscience Centre, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, PR China; Department of Anesthesiology, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, PR China.
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Pejo E, Liu J, Lin X, Raines DE. Distinct Hypnotic Recoveries After Infusions of Methoxycarbonyl Etomidate and Cyclopropyl Methoxycarbonyl Metomidate: The Role of the Metabolite. Anesth Analg 2016; 122:1008-14. [PMID: 26991617 DOI: 10.1213/ane.0000000000001146] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND Methoxycarbonyl etomidate (MOC-etomidate) and cyclopropyl methoxycarbonyl metomidate (CPMM) are rapidly metabolized "soft" etomidate analogs. CPMM's duration of hypnotic effect is context insensitive, whereas MOC-etomidate's is not. In this study, we tested the hypothesis that CPMM's effect is context insensitive because, unlike MOC-etomidate, its metabolite fails to reach physiologically important concentrations in vivo even with prolonged continuous infusion. METHODS We compared the potencies with which MOC-etomidate and CPMM activate α1(L264T)β3γ2 γ-aminobutyric acid type A receptors and induce loss-of-righting reflexes (i.e., produce hypnosis) in tadpoles with those of their metabolites (MOC-etomidate's carboxylic acid metabolite [MOC-ECA] and CPMM's carboxylic acid metabolite [CPMM-CA], respectively). We measured metabolite concentrations in the blood and cerebrospinal fluid of Sprague-Dawley rats on CPMM infusion and compared them with those achieved with MOC-etomidate infusion. We measured the rates with which brain tissue from Sprague-Dawley rats metabolize MOC-etomidate and CPMM. RESULTS Both analogs and their metabolites enhanced γ-aminobutyric acid type A receptor function and induced loss-of-righting reflexes in a concentration-dependent manner. However, in these 2 assays, CPMM-CA's potency relative to its parent hypnotic was approximately 1:4900 and 1:1900, respectively, whereas MOC-ECA's was only approximately 1:415 and 1:390, respectively. With 2-hour CPMM infusions, CPMM-CA reached respective concentrations in the blood and cerebrospinal fluid that were 2 and >3 orders of magnitude lower than that which produced hypnosis. CPMM was metabolized by the brain tissue at a rate that is approximately 1/15th that of MOC-etomidate. CONCLUSIONS Hypnotic recovery after CPMM administration is context insensitive because its metabolite does not accumulate to hypnotic levels in the central nervous system. This reflects the very large potency ratio between CPMM and CPMM-CA and the resistance of CPMM to metabolism by esterases present in the brain.
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Affiliation(s)
- Ervin Pejo
- From the *Department of Anesthesia, Critical Care, and Pain Medicine, Massachusetts General Hospital, Boston, Massachusetts; and †Aberjona Laboratories, Woburn, Massachusetts
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Cyclopropyl-methoxycarbonyl Metomidate: Studies in a Lipopolysaccharide Inflammatory Model of Sepsis. Anesthesiology 2015; 123:368-76. [PMID: 26035348 DOI: 10.1097/aln.0000000000000721] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Cyclopropyl-methoxycarbonyl metomidate (CPMM) is a rapidly metabolized etomidate analog that is currently in clinical trials. The goal of this study is to assess CPMM's potential value as an anesthetic agent for use in patients with sepsis by defining its actions in an acute inflammatory model of sepsis. METHODS Escherichia coli lipopolysaccharide (1 mg/kg) was injected intravenously into Sprague-Dawley rats. Thirty minutes later, CPMM, etomidate, or vehicle (n = 8 per group) was infused for 1 h. Plasma adrenocorticotropic hormone, corticosterone, and cytokine (interleukin-1β, interleukin-6, interleukin-10, and tumor necrosis factor-α) concentrations were measured before, during, and after infusion. RESULTS After lipopolysaccharide injection, adrenocorticotropic hormone concentrations changed similarly over time in all three groups. Compared with vehicle group rats, CPMM group rats had significantly lower corticosterone concentrations at only a single study time point during infusion and no significant differences in cytokine concentrations at any time during the study period. Compared with etomidate group rats, CPMM group rats had significantly higher corticosterone concentrations (up to nine-fold) during and after hypnotic infusion. Cytokine concentrations in CPMM group rats and vehicle group rats were not significantly different, but they were significantly lower than those in etomidate group rats. Postinfusion mortality was 40% in etomidate group rats and 0% in CPMM and vehicle group rats. CONCLUSION Compared with etomidate, CPMM produces less adrenocortical suppression, lower plasma cytokine concentrations, and improved survival in a lipopolysaccharide inflammatory model of sepsis. These results suggest that CPMM may be a safer alternative to etomidate in patients with sepsis.
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Advancing novel anesthetics: pharmacodynamic and pharmacokinetic studies of cyclopropyl-methoxycarbonyl metomidate in dogs. Anesthesiology 2015; 121:1203-16. [PMID: 25170571 DOI: 10.1097/aln.0000000000000416] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Cyclopropyl-methoxycarbonyl metomidate (CPMM, also known as ABP-700) is a second-generation "soft" (i.e., metabolically labile) etomidate analogue. The purpose of this study was to characterize CPMM's pharmacology in beagle dogs in preparation for potential first in human phase 1 clinical trials. METHODS CPMM's and etomidate's hypnotic activity and duration of action were assessed using loss of righting reflex and anesthesia score assays in three or four dogs. Their pharmacokinetics were defined after single bolus administration and single bolus followed by 2-h infusion. Adrenocortical recovery times after single bolus followed by 2-h infusion of CPMM, propofol, etomidate, and vehicle were measured using an adrenocorticotropic hormone stimulation test. RESULTS Compared with etomidate, CPMM was half as potent as a hypnotic (ED50 approximately 0.8 mg/kg), was more rapidly metabolized, and had a shorter duration of sedative-hypnotic action. Recovery times after CPMM administration were also independent of infusion duration. After hypnotic infusion, adrenocorticotropic hormone-stimulated plasma cortisol concentrations were 4- to 27-fold higher in dogs that received CPMM versus etomidate. Adrenocortical recovery was faster in dogs after CPMM infusion versus etomidate infusion (half-time: 215 vs. 1,623 min, respectively). Adrenocortical responsiveness assessed 90 min after CPMM infusion was not significantly different from that after propofol infusion. CONCLUSION The studies in dogs confirm that CPMM has hypnotic and adrenocortical recovery profiles that are superior than those of etomidate, supporting the continued development of CPMM as a clinical sedative-hypnotic to be used as a single bolus and by continuous infusion to induce and maintain general anesthesia or procedural sedation.
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Melton MS, Nielsen KC, Tucker M, Klein SM, Gan TJ. New medications and techniques in ambulatory anesthesia. Anesthesiol Clin 2014; 32:463-485. [PMID: 24882131 DOI: 10.1016/j.anclin.2014.02.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Novel anesthetic and analgesic agents are currently under development or investigation to improve anesthetic delivery and patient care. The pharmacokinetic and analgesic profiles of these agents are especially tailored to meet the challenges of rapid recovery and opioid minimization associated with ambulatory anesthesia practice.
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Affiliation(s)
- M Stephen Melton
- Department of Anesthesiology, Duke University Medical Center, Box 3094, Durham, NC 27710, USA
| | - Karen C Nielsen
- Department of Anesthesiology, Duke University Medical Center, Box 3094, Durham, NC 27710, USA
| | - Marcy Tucker
- Department of Anesthesiology, Duke University Medical Center, Box 3094, Durham, NC 27710, USA
| | - Stephen M Klein
- Department of Anesthesiology, Duke University Medical Center, Box 3094, Durham, NC 27710, USA
| | - Tong J Gan
- Department of Anesthesiology, Duke University Medical Center, Box 3094, Durham, NC 27710, USA.
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Ge R, Pejo E, Gallin H, Jeffrey S, Cotten JF, Raines DE. The pharmacology of cyclopropyl-methoxycarbonyl metomidate: a comparison with propofol. Anesth Analg 2014; 118:563-7. [PMID: 24557104 PMCID: PMC6310170 DOI: 10.1213/ane.0000000000000069] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND Cyclopropyl-methoxycarbonyl metomidate (CPMM) is a "soft" etomidate analogue currently being developed as a propofol alternative for anesthetic induction and maintenance. METHODS We compared the potencies of CPMM and propofol by assessing their abilities to directly activate α1(L264T)β3γ2 gamma-aminobutyric acid type A (GABAA) receptors and induce loss of righting reflexes in tadpoles. We also measured the rates of encephalographic recovery in rats after CPMM and propofol infusions ranging in duration from 5 to 120 minutes. RESULTS CPMM and propofol activate GABAA receptors and induce loss of righting reflexes in tadpoles with respective 50% effective concentrations (EC50s) of 3.8 ± 0.4 and 3.9 ± 0.2 μM (GABAA receptor) and 2.6 ± 0.19 and 1.3 ± 0.04 μM (tadpole). Encephalographic recovery after prolonged infusion was faster with CPMM and lacked propofol's context sensitivity. CONCLUSION CPMM and propofol have similar potencies in GABAA receptors and tadpoles; however, CPMM provides more rapid and predictable recovery than propofol, particularly after prolonged infusion.
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Affiliation(s)
- Rile Ge
- Department of Anesthesia, Perioperative and Pain Medicine, Boston Children’s Hospital
| | - Ervin Pejo
- Department of Anesthesia, Critical Care, and Pain Medicine, Massachusetts General Hospital, Boston, Massachusetts
| | - Hilary Gallin
- Washington University School of Medicine, St. Louis, Missouri
| | - Spencer Jeffrey
- Department of Anesthesia, Critical Care, and Pain Medicine, Massachusetts General Hospital, Boston, Massachusetts
| | - Joseph F. Cotten
- Department of Anesthesia, Critical Care, and Pain Medicine, Massachusetts General Hospital, Boston, Massachusetts
| | - Douglas E. Raines
- Department of Anesthesia, Critical Care, and Pain Medicine, Massachusetts General Hospital, Boston, Massachusetts
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Modifying methoxycarbonyl etomidate inter-ester spacer optimizes in vitro metabolic stability and in vivo hypnotic potency and duration of action. Anesthesiology 2013; 117:1027-36. [PMID: 22929736 DOI: 10.1097/aln.0b013e31826d3bef] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Methoxycarbonyl etomidate is the prototypical very rapidly metabolized etomidate analog. Initial studies suggest that it may be too short acting for many clinical uses. We hypothesized that its duration of action could be lengthened and clinical utility broadened by incorporating specific aliphatic groups into the molecule to sterically protect its ester moiety from esterase-catalyzed hydrolysis. To test this hypothesis, we developed a series of methoxycarbonyl etomidate analogs (spacer-linked etomidate esters) containing various aliphatic-protecting groups and spacer lengths. METHODS Spacer-linked etomidate esters were synthesized and their hypnotic potencies and durations of action following bolus administration were measured in rats using a loss-of-righting reflexes assay. Octanol:water partition coefficients and metabolic half-lives in pooled rat blood were determined chromatographically. RESULTS All spacer-linked etomidate esters produced hypnosis rapidly and in a dose-dependent manner. ED50s for loss of righting reflexes ranged from 0.69 ± 0.04 mg/kg for cyclopropyl-methoxycarbonyl metomidate to 11.1 ± 0.8 mg/kg for methoxycarbonyl metomidate. The slope of a plot of the duration of loss of righting reflexes versus the logarithm of the dose ranged 12-fold among spacer-linked etomidate esters, implying widely varying brain clearance rates. The in vitro metabolic half-lives of these compounds in rat blood varied by more than two orders of magnitude and were diastereometrically selective. CONCLUSIONS We created 13 new analogs of methoxycarbonyl etomidate and identified two that have significantly higher potency and potentially address the too-brief duration of action for methoxycarbonyl etomidate. This work may provide a blueprint for optimizing the pharmacological properties of other soft drugs.
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Electroencephalographic and hypnotic recoveries after brief and prolonged infusions of etomidate and optimized soft etomidate analogs. Anesthesiology 2013; 117:1037-43. [PMID: 22929726 DOI: 10.1097/aln.0b013e31826d3de2] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
BACKGROUND Methoxycarbonyl etomidate is the prototypical soft etomidate analog. Because it has relatively low potency and is extremely rapidly metabolized, large quantities must be infused to maintain hypnosis. Consequently with prolonged infusion, metabolite reaches sufficient concentrations to delay recovery. Dimethyl-methoxycarbonyl metomidate (DMMM) and cyclopropyl-methoxycarbonyl metomidate (CPMM) are methoxycarbonyl etomidate analogs with higher potencies and slower clearance. Because of these properties, we hypothesized that dosing would be lower and electroencephalographic and hypnotic recoveries would be faster - and less context-sensitive - with DMMM or CPMM versus methoxycarbonyl etomidate or etomidate. METHODS Etomidate, DMMM, and CPMM where infused into rats (n = 6 per group) for either 5 min or 120 min. After infusion termination, electroencephalographic and hypnotic recovery times were measured. The immobilizing ED50 infusion rates were determined using a tail clamp assay. RESULTS Upon terminating 5-min infusions, electroencephalographic and hypnotic recovery times were not different among hypnotics. However, upon terminating 120-min infusions, recovery times varied significantly with respective values (mean ± SD) 48 ± 13 min and 31 ± 6.5 min (etomidate), 17 ± 7.0 min and 14 ± 3.4 min (DMMM), and 4.5 ± 1.1 min and 4.2 ± 1.6 min (CPMM). The immobilizing ED50 infusion rates were (mean ± SD) 0.19 ± 0.03 mg · kg · min (etomidate), 0.60 ± 0.12 mg · kg · min (DMMM), and 0.89 ± 0.18 mg · kg · min (CPMM). CONCLUSIONS Electroencephalographic and hypnotic recoveries following prolonged infusions of DMMM and CPMM are faster than those following methoxycarbonyl etomidate or etomidate. In the case of CPMM infusion, recovery times are 4 min and context-insensitive.
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Chitilian HV, Eckenhoff RG, Raines DE. Anesthetic drug development: Novel drugs and new approaches. Surg Neurol Int 2013; 4:S2-S10. [PMID: 23653886 PMCID: PMC3642742 DOI: 10.4103/2152-7806.109179] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2012] [Accepted: 08/08/2012] [Indexed: 12/17/2022] Open
Abstract
The ideal sedative–hypnotic drug would be a rapidly titratable intravenous agent with a high therapeutic index and minimal side effects. The current efforts to develop such agents are primarily focused on modifying the structures of existing drugs to improve their pharmacodynamic and pharmacokinetic properties. Drugs currently under development using this rational design approach include analogues of midazolam, propofol, and etomidate, such as remimazolam, PF0713, and cyclopropyl methoxycarbonyl-etomidate (MOC-etomidate), respectively. An alternative approach involves the rapid screening of large libraries of molecules for activity in structural or phenotypic assays that approximate anesthetic and target receptor interactions. Such high-throughput screening offers the potential for identifying completely novel classes of drugs. Anesthetic drug development is experiencing a resurgence of interest because there are new demands on our clinical practice that can be met, at least in part, with better agents. The goal of this review is to provide the reader with a glimpse of the novel anesthetic drugs and new developmental approaches that lie on the horizon.
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Affiliation(s)
- Hovig V Chitilian
- Department of Anesthesia, Critical Care, and Pain Medicine, Massachusetts General Hospital, Boston, MA, USA
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Ge R, Pejo E, Cotten JF, Raines DE. Adrenocortical suppression and recovery after continuous hypnotic infusion: etomidate versus its soft analogue cyclopropyl-methoxycarbonyl metomidate. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2013; 17:R20. [PMID: 23363638 PMCID: PMC4057162 DOI: 10.1186/cc12494] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/10/2012] [Accepted: 01/29/2013] [Indexed: 11/10/2022]
Abstract
Introduction Etomidate is no longer administered as a continuous infusion for anesthetic maintenance or sedation, because it results in profound and persistent suppression of adrenocortical steroid synthesis with potentially lethal consequences in critically ill patients. We hypothesized that rapidly metabolized soft analogues of etomidate could be developed that do not produce persistent adrenocortical dysfunction even after prolonged continuous infusion. We hope that such agents might also provide more rapid and predictable anesthetic emergence. We have developed the soft etomidate analogue cyclopropyl-methoxycarbonyl etomidate (CPMM). Upon termination of 120-minute continuous infusions, hypnotic and encephalographic recoveries occur in four minutes. The aims of this study were to assess adrenocortical function during and following 120-minute continuous infusion of CPMM and to compare the results with those obtained using etomidate. Methods Dexamethasone-suppressed rats were randomized into an etomidate group, CPMM group, or control group. Rats in the etomidate and CPMM groups received 120-minute continuous infusions of etomidate and CPMM, respectively. Rats in the control group received neither hypnotic. In the first study, adrenocortical function during hypnotic infusion was assessed by administering adrenocorticotropic hormone (ACTH) 90 minutes after the start of the hypnotic infusion and measuring plasma corticosterone concentrations at the end of the infusion 30 minutes later. In the second study, adrenocortical recovery following hypnotic infusion was assessed by administering ACTH every 30 minutes after infusion termination and measuring plasma corticosterone concentrations 30 minutes after each ACTH dose. Results During hypnotic infusion, ACTH-stimulated serum corticosterone concentrations were significantly lower in the CPMM and etomidate groups than in the control group (100 ± 64 ng/ml and 33 ± 32 ng/ml versus 615 ± 265 ng/ml, respectively). After hypnotic infusion, ACTH-stimulated serum corticosterone concentrations recovered to control values within 30 minutes in the CPMM group but remained suppressed relative to those in the control group for more than 3 hours in the etomidate group. Conclusions Both CPMM and etomidate suppress adrenocortical function during continuous infusion. However, recovery occurs significantly more rapidly following infusion of CPMM.
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