Reversing neuromuscular blockade: inhibitors of the acetylcholinesterase versus the encapsulating agents sugammadex and calabadion

Unraveling the molecular dynamics of sugammadex-rocuronium complexation: A blueprint for cyclodextrin drug design

Sugammadex, marketed as Bridion™, is an approved cyclodextrin (CD) based drug for the reversal of neuromuscular blockade in adults undergoing surgery. Sugammadex forms an inclusion complex with the neuromuscular blocking agent (NMBA) rocuronium, allowing rapid reversal of muscle paralysis. In silico methods have been developed for studying CD inclusion complexes, aimed at accurately predicting their structural, energetic, dynamic, and kinetic properties, as well as binding constants. Here, a computational study aimed at characterizing the sugammadex-rocuronium system from the perspective of docking calculations, free molecular dynamics (MD) simulations, and biased metadynamics simulations with potential of mean force (PMF) calculations is presented. The aim is to provide detailed information about this system, as well as to use it as a model system for validation of the methods. This method predicts results in line with experimental evidence for both the optimal structure and the quantitative value for the binding constant. Interestingly, there is a less profound preference for the orientation than might be assumed based on electrostatic interactions, suggesting that both orientations may exist in solution. These results show that this technology can efficiently analyze CD inclusion complexes and could be used to facilitate the development and optimization of novel applications for CDs.

Comparison of the effects of sugammadex versus neostigmine for reversal of neuromuscular block on hospital costs of care

BACKGROUND

Sugammadex reversal of neuromuscular block facilitates recovery of neuromuscular function after surgery, but the drug is expensive. We evaluated the effects of sugammadex on hospital costs of care.

METHODS

We analysed 79 474 adult surgical patients who received neuromuscular blocking agents and reversal from two academic healthcare networks between 2016 and 2021 to calculate differences in direct costs. We matched our data with data from the Healthcare Cost and Utilization Project-National Inpatient Sample (HCUP-NIS) to calculate differences in total costs in US dollars. Perioperative risk profiles were defined based on ASA physical status and admission status (ambulatory surgery vs hospitalisation).

RESULTS

Based on our registry data analysis, administration of sugammadex vs neostigmine was associated with lower direct costs (-1.3% lower costs; 95% confidence interval [CI], -0.5 to -2.2%; P=0.002). In the HCUP-NIS matched cohort, sugammadex use was associated with US$232 lower total costs (95% CI, -US$376 to -US$88; P=0.002). Subgroup analysis revealed that sugammadex was associated with US$1042 lower total costs (95% CI, -US$1198 to -US$884; P<0.001) in patients with lower risk. In contrast, sugammadex was associated with US$620 higher total costs (95% CI, US$377 to US$865; P<0.001) in patients with a higher risk (American Society of Anesthesiologists physical status ≥3 and preoperative hospitalisation).

CONCLUSIONS

The effects of using sugammadex on costs of care depend on patient risk, defined based on comorbidities and admission status. We observed lower costs of care in patients with lower risk and higher costs of care in hospitalised surgical patients with severe comorbidities.

Influence of sugammadex versus neostigmine for neuromuscular block reversal on the incidence of postoperative pulmonary complications: a meta-analysis of randomized controlled trials

BACKGROUND

The influence of sugammadex for reversal of neuromuscular block (NMB) on postoperative pulmonary complications (PPCs), compared with neostigmine, remains to be determined. We performed a meta-analysis of randomized controlled trials (RCTs) to compare the incidence of PPCs between patients who received sugammadex versus neostigmine.

METHODS

Relevant studies were obtained by searching the PubMed, Embase, and Cochrane Library databases. A random effects model incorporating the potential heterogeneity was used to pool the results.

RESULTS

Fourteen RCTs including 1478 adult patients who underwent surgeries with general anesthesia were included, and of these, 753 received sugammadex and 725 received neostigmine for reversal of NMB. The pooled results showed that sugammadex was associated with a lower risk of overall PPCs compared to neostigmine (odds ratio [OR]: 0.62, 95% confidence interval [CI]: 0.43-0.89, p = 0.01; I² = 0%). This finding remained consistent after exclusion of two studies with potential overlapping events (OR: 0.58, 95% CI: 0.36-0.96, p = 0.03; I²=9%). Stratified analyses according to the categories of PPCs showed that sugammadex was associated with a significantly lower risk of postoperative respiratory failure (OR: 0.60, 95% CI: 0.38-0.97, p = 0.04; I² = 0%) but not of postoperative pulmonary infection (OR: 0.79, p = 0.71), atelectasis (OR: 0.78, p = 0.33), or pneumothorax (OR: 0.87, p = 0.79).

CONCLUSIONS

Compared with neostigmine, the use of sugammadex for reversal of NMB was associated with a lower risk of PPCs, mainly due to a lower incidence of postoperative respiratory failure with the use of sugammadex.

A Clinical and Budgetary Impact Analysis of Introducing Sugammadex for Routine Reversal of Neuromuscular Blockade in a Hypothetical Cohort in the US

INTRODUCTION

Sugammadex rapidly reverses the effects of rocuronium- and vecuronium-induced neuromuscular blockade (NMB), offering a more complete and predictable NMB recovery than cholinesterase inhibitors. Despite clinical benefits, cost pressures on hospital budgets influence the choice of the NMB reversal method. This study evaluated clinical and healthcare system payer's budget impacts associated with sugammadex in the US for routine reversal of moderate or deep rocuronium- or vecuronium-induced NMB in adults undergoing surgery.

METHODS

A 1-year decision analytic model was constructed reflecting a set of procedures using rocuronium or vecuronium that resulted in moderate or deep NMB at the end of surgery. Two scenarios were considered for a hypothetical cohort of 100,000 patients: without sugammadex versus with sugammadex. Comparators included neostigmine (+glycopyrrolate) and no neuromuscular blocking agents (NMBAs). Total costs (in 2019 US dollars) to a healthcare system [net of costs of reversal agents and overall cost offsets via reduction in postoperative pulmonary complications (PPC)] were compared.

RESULTS

A total of 9971 surgical procedures utilized rocuronium or vecuronium, resulting in moderate (91.0% of cases) or deep (9.0%) blockade at the end of surgeries. In the with sugammadex scenario, sugammadex replaced neostigmine in 4156 of 9585 procedures versus the without sugammadex scenario that used only neostigmine for NMB reversal. Introducing sugammadex reduced PPC events by 12% (58 cases) among the modeled procedures, leading to a budget impact of -$3,079,703 (-$309 per modeled procedure, or a 10.9% reduction in total costs). The results did not vary qualitatively in one-way sensitivity analyses.

CONCLUSIONS

The additional costs of sugammadex for the reversal of rocuronium- or vecuronium-induced NMB could be offset by improved outcomes (i.e., reduced PPC events), and potentially lead to overall healthcare budgetary savings versus reversal with neostigmine or spontaneous recovery. This study provides insights into savings that can be obtained beyond the anesthesia budget, reducing the broader clinical and budgetary burden on the hospital.

Chemical and Pharmacological Screening of Rhinella icterica (Spix 1824) Toad Parotoid Secretion in Avian Preparations

The biological activity of Rhinella icterica parotoid secretion (RIPS) and some of its chromatographic fractions (RI18, RI19, RI23, and RI24) was evaluated in the current study. Mass spectrometry of these fractions indicated the presence of sarmentogenin, argentinogenin, (5β,12β)-12,14-dihydroxy-11-oxobufa-3,20,22-trienolide, marinobufagin, bufogenin B, 11α,19-dihydroxy-telocinobufagin, bufotalin, monohydroxylbufotalin, 19-oxo-cinobufagin, 3α,12β,25,26-tetrahydroxy-7-oxo-5β-cholestane-26-O-sulfate, and cinobufagin-3-hemisuberate that were identified as alkaloid and steroid compounds, in addition to marinoic acid and N-methyl-5-hydroxy-tryptamine. In chick brain slices, all fractions caused a slight decrease in cell viability, as also seen with the highest concentration of RIPS tested. In chick biventer cervicis neuromuscular preparations, RIPS and all four fractions significantly inhibited junctional acetylcholinesterase (AChE) activity. In this preparation, only fraction RI23 completely mimicked the pharmacological profile of RIPS, which included a transient facilitation in the amplitude of muscle twitches followed by progressive and complete neuromuscular blockade. Mass spectrometric analysis showed that RI23 consisted predominantly of bufogenins, a class of steroidal compounds known for their cardiotonic activity mediated by a digoxin- or ouabain-like action and the blockade of voltage-dependent L-type calcium channels. These findings indicate that the pharmacological activities of RI23 (and RIPS) are probably mediated by: (1) inhibition of AChE activity that increases the junctional content of Ach; (2) inhibition of neuronal Na⁺/K⁺-ATPase, leading to facilitation followed by neuromuscular blockade; and (3) blockade of voltage-dependent Ca²⁺ channels, leading to stabilization of the motor endplate membrane.

Current use of neuromuscular blocking agents and antagonists in Korea: a 2018 survey

Background

Neuromuscular blocking agents (NMBAs) and neuromuscular monitoring in anesthetic management are integral for endotracheal intubation, better visualization of the surgical field, and prevention of residual neuromuscular blockade and pulmonary complications. Sugammadex is a drug that reduces risk of residual neuromuscular blockade, with more rapid recovery compared to anticholinesterase. The purpose of this study was to investigate current usage status of NMBAs and antagonist with neuromuscular monitoring, among anesthesiologists in Korea.

Methods

Anesthesiologists working in Korea were invited to participate in an online survey via email January 2–February 28, 2018. The questionnaire consisted of 45 items, including preferred NMBAs, antagonists, neuromuscular monitoring, and complications related to the use sugammadex. A total of 174 responses were analyzed.

Results

Rocuronium was a commonly used NMBA for endotracheal intubation (98%) of hospitals, and maintenance of anesthesia (83.3%) in of hospitals. Sugammadex, pyridostigmine, and neostigmine were used in 89.1%, 87.9%, and 45.4% of hospitals. Neuromuscular monitoring was employed in 79.3% of hospitals; however only 39.7% of hospitals used neuromuscular monitoring before antagonist administration. Usual dosage range of sugammadex was 2.1–4 mg/kg in 35.1% of hospitals, within 2 mg/kg in 34.5% of hospitals, and 1 vial regardless of body weight in 22.4% of hospitals. Sugammadexrelated complications were encountered by 14.9% of respondents.

Conclusions

This survey indicates several minor problems associated with the use of antagonists and neuromuscular monitoring. However, most anesthesiologists appear to have appropriate information regarding the usage of NMBAs and sugammadex.

Survey of neuromuscular monitoring and assessment of postoperative residual neuromuscular block in a postoperative anaesthetic care unit

INTRODUCTION

The use of neuromuscular blocking agents (NMBAs) is common during general anaesthesia. Neuromuscular monitoring with a peripheral nerve stimulator (PNS) is essential to prevent postoperative residual neuromuscular block (PRNB), defined as a train-of-four (TOF) ratio < 0.9. PRNB remains a common complication and may contribute to morbidity in the postoperative anaesthetic care unit (PACU).

METHODS

An online survey was sent to anaesthesiologists in our department to assess their knowledge and clinical practices related to neuromuscular blockade. Next, a study was conducted on adult patients scheduled for elective surgery under general anaesthesia requiring NMBAs. Upon admission to the PACU, TOF monitoring was performed.

RESULTS

A large proportion of anaesthesiologists showed a lack of knowledge of neuromuscular blockade or non-adherence to the best clinical practices associated with it. The majority (98.7%) stated that they did not routinely use PNS monitoring. In the clinical study, TOF monitoring was only used in 17.9% of the 335 patients who were assessed. The prevalence of PRNB was 33.4% and was associated with the elderly (age ≥ 65 years), a higher dose of NMBA used, a shorter duration of surgery, and a shorter duration between the last dose of NMBA and measurement of PRNB in the PACU. The incidence of adverse symptoms in the PACU was observed to be higher in patients with PRNB.

CONCLUSION

PRNB remains a clinically significant problem, but routine PNS monitoring is rare in our institution. This is compounded by inadequate knowledge and poor adherence to best clinical guidelines related to neuromuscular blockade.

Residual Neuromuscular Blockade in the Critical Care Setting

Residual neuromuscular blockade is a widespread challenge for providers in the acute care setting that, if left unrecognized or untreated, places patients at higher risk for morbidity and mortality. The condition is estimated to occur in 26% to 88% of patients undergoing general anesthesia. The role of the advanced practice nurse in the acute care setting is to facilitate a safe recovery process by identifying early signs of deterioration and supporting the patient until full muscular strength has returned. This article discusses the prevalence of residual neuromuscular blockade and associated complications and patient risk factors. A review is included of the current uses for neuromuscular blockade, pathophysiology of the neuromuscular junction, pharmacologic characteristics of neuromuscular blocking agents (including drug-drug interactions), monitoring modalities, and effectiveness of reversal agents. Treatment recommendations pertinent to residual neuromuscular blockade are outlined.

New Drug Developments for Neuromuscular Blockade and Reversal: Gantacurium, CW002, CW011, and Calabadion

Purpose of Review

The purpose of this chapter is to provide a brief review of the literature on the recent developments in neuromuscular blockade and reversal agents.

Recent Findings

Novel drug development resulted in pharmacological advancements in neuromuscular management and led to a new series of compounds, chlorofumarates, such as gantacurium, CW002, and CW011. These drugs have a fast onset and rapid to intermediate duration of action and can be rapidly reversed by l-cysteine adduction without side effects that are commonly observed with anticholinesterase reversal drugs. Another new advancement is the development of a new class of reversal drugs, the calabadions. These drugs are able to reverse both steroidal and non-steroidal non-depolarizing neuromuscular blocking drugs rapidly.

Summary

Recent advancements in neuromuscular blocking agents and reversal drugs have shown promise in improving safety of management of neuromuscular blockade. Preclinical and clinical studies are discussed. However, to date these new drugs are not yet available for clinical use.

Neuronal Effects of Sugammadex in combination with Rocuronium or Vecuronium

Rocuronium (ROC) and Vecuronium (VEC) are the most currently used steroidal non-depolarizing neuromuscular blocking (MNB) agents. Sugammadex (SUG) rapidly reverses steroidal NMB agents after anaesthesia. The present study was conducted in order to evaluate neuronal effects of SUG alone and in combination with both ROC and VEC. Using MTT, CASP-3 activity and Western-blot we determined the toxicity of SUG, ROC or VEC in neurons in primary culture. SUG induces apoptosis/necrosis in neurons in primary culture and increases cytochrome C (CytC), apoptosis-inducing factor (AIF), Smac/Diablo and Caspase 3 (CASP-3) protein expression. Our results also demonstrated that both ROC and VEC prevent these SUG effects. The protective role of both ROC and VEC could be explained by the fact that SUG encapsulates NMB drugs. In BBB impaired conditions it would be desirable to control SUG doses to prevent the excess of free SUG in plasma that may induce neuronal damage. A balance between SUG, ROC or VEC would be necessary to prevent the risk of cell damage.

Lactucopicrin ameliorates oxidative stress mediated by scopolamine-induced neurotoxicity through activation of the NRF2 pathway

Cholinergic activity plays a vital role in cognitive function, and is reduced in individuals with neurodegenerative diseases. Scopolamine, a muscarinic cholinergic antagonist, has been employed in many studies to understand, identify, and characterize therapeutic targets for Alzheimer's disease (AD). Scopolamine-induced dementia is associated with impairments in memory and cognitive function, as seen in patients with AD. The current study aimed to investigate the molecular mechanisms underlying scopolamine-induced cholinergic neuronal dysfunction and the neuroprotective effect of lactucopicrin, an inhibitor of acetylcholine esterase (AChE). We investigated apoptotic cell death, caspase activation, generation of reactive oxygen species (ROS), mitochondrial dysfunction, and the expression levels of anti- and pro-apoptotic proteins in scopolamine-treated C6 cells. We also analyzed the expression levels of antioxidant enzymes and nuclear factor (erythroid-derived 2)-like 2 (NRF2) in C6 cells and neurite outgrowth in N2a neuroblastoma cells. Our results revealed that 1 h scopolamine pre-treatment induced cytotoxicity by increasing apoptotic cell death via oxidative stress-mediated caspase 3 activation and mitochondrial dysfunction. Scopolamine also downregulated the expression the antioxidant enzymes superoxide dismutase, glutathione peroxidase, and catalase, and the transcription factor NRF2. Lactucopicrin treatment protected C6 cells from scopolamine-induced toxicity by reversing the effects of scopolamine on those markers of toxicity. In addition, scopolamine attenuated the secretion of neurotrophic nerve growth factor (NGF) in C6 cells and neurite outgrowth in N2a cells. As expected, lactucopicrin treatment enhanced NGF secretion and neurite outgrowth. Our study is the first to show that lactucopicrin, a potential neuroprotective agent, ameliorates scopolamine-induced cholinergic dysfunction via NRF2 activation and subsequent expression of antioxidant enzymes.