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Background: Cholinesterase inhibitors (ChEIs) are regularly used in Alzheimer's disease. Of the three ChEIs approved for dementia, donepezil is among the most prescribed drugs in the United States with nearly 6 million prescriptions in 2020; however, it is classified as a "known risk" QT interval-prolonging medication (QTPmed). Given this claim is derived from observational data including single case reports, we aimed to evaluate high-quality literature on the frequency and nature of proarrhythmic major adverse cardiac events (MACE) associated with donepezil., Methods: We searched Medline, Embase, International Pharmaceutical Abstracts, and Cochrane Central from 1996 onwards for randomized controlled trials (RCTs) involving patients age ≥18 years comparing donepezil to placebo. The MACE composite included mortality, sudden cardiac death, non-fatal cardiac arrest, Torsades de pointes, ventricular tachyarrhythmia, seizure or syncope. Random-effects meta-analyses were performed with a treatment-arm continuity correction for single and double zero event studies., Results: Sixty RCTs (n = 12,463) were included. Twenty-five of 60 trials (n = 5886) investigated participants with Alzheimer's disease and 33 trials monitored electrocardiogram data. The mean follow-up duration was 31 weeks (SD = 36). Mortality was the most commonly reported MACE (252/331, 75.8% events), the remainder were syncope or seizures, with no arrhythmia events. There was no increased risk of MACE with exposure to donepezil compared to placebo (risk ratio [RR] 1.08, 95% CI 0.88-1.33, I 2  = 0%) and this was consistent in the subgroup analysis of trials including participants with cardiovascular morbidities (RR 1.14, 95% CI 0.88-1.47). Subgroup analysis suggested a trend toward more events with donepezil with follow-up ≥52 weeks (RR: 1.32, 0.98-1.79)., Conclusions: This systematic review with meta-analysis found donepezil may not be arrhythmogenic. Donepezil was not associated with mortality, ventricular arrhythmias, seizure or syncope, although longer durations of therapy need more study. Further research to clarify actual clinical outcomes related to QTPmed is important to inform prescribing practices., (© 2024 The Authors. Journal of the American Geriatrics Society published by Wiley Periodicals LLC on behalf of The American Geriatrics Society.)

Background: Postoperative gastrointestinal dysfunction (POGD) commonly occurs following gastrointestinal (GI) surgery and is associated with specific anesthetic agents. Cholinesterase inhibitors employed for reversing neuromuscular blockade have been implicated in development of POGD. Sugammadex, a novel reversal agent, is linked with reduced POGD. However, there is a lack of comprehensive comparative review between these agents regarding their impact on POGD following GI surgery. This study aims to systematically review the effects of sugammadex on POGD compared to cholinesterase inhibitors following GI surgery., Methods: MEDLINE, EMBASE, and CENTRAL were searched as of July 2022 to identify articles comparing sugammadex with cholinesterase inhibitors in patients undergoing gastrointestinal surgery, specifically in relation to POGD. Secondary endpoints included length of hospital stay, readmission rates, pulmonary complications, and postoperative morbidity., Results: From 198 citations, 2 randomized controlled trials (RCTs) and 3 retrospective cohorts with 717 patients receiving sugammadex and 812 patients receiving cholinesterase inhibitors were included. Significantly lower rates of prolonged postoperative ileus (OR .44, 95% CI .25-.77, P < .05, I 2 = 56%, low certainty evidence) was observed with sugammadex. No significant difference in any other outcome was observed. Narrative review of readmission data demonstrated no significant difference., Conclusion: The use of sugammadex following gastrointestinal surgery is associated with significantly lower rates of prolonged postoperative ileus compared to cholinesterase inhibitors. However, these do not translate into a significant reduction in length of stay, morbidity, or postoperative nausea and vomiting. Results are limited by the numer of studies included and missing data, more robust RCTs are needed before recommendations can be made., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Background: Postoperative ileus, driven by the cholinergic anti-inflammatory pathway, is the most common complication in patients undergoing colorectal surgery. By inhibiting acetylcholinesterase, pyridostigmine can potentially modulate the cholinergic anti-inflammatory pathway and accelerate gastrointestinal recovery. This study aimed to assess the efficacy of pyridostigmine in improving gastrointestinal recovery after colorectal surgery., Methods: This double-blinded RCT enrolled adult patients undergoing elective colorectal surgery at two hospitals in South Australia. Patients were randomized to 60 mg oral pyridostigmine or placebo twice daily starting 6 h after surgery until the first passage of stool. The primary outcome was GI-2, a validated composite measure of time to first stool and tolerance of oral diet. Secondary outcomes included incidence of postoperative ileus (defined as GI-2 greater than 4 days), duration of hospital stay, and 30-day complications, evaluated by intention-to-treat univariate analysis., Results: Of 130 patients recruited (mean(s.d.) age 58.4(16.4) years; 73 men, 56%), 65 were allocated to each arm. The median GI-2 was 1 day shorter with pyridostigmine compared with placebo (2 (i.q.r. 1-3) versus 3 (2-4) days; P = 0.015). However, there were no significant differences in postoperative ileus (17.2 versus 21.5%; P = 0.532) or duration of hospital stay (median 5 (i.q.r. 4-8.75) versus 5 (4-7.5) days; P = 0.921). Similarly, there were no significant differences in overall complications, anastomotic leak, cardiac complications, or patient-reported side effects., Conclusion: Pyridostigmine resulted in a quicker return of GI-2 and was well tolerated. Larger multicentre studies are required to determine the optimal dosing and evaluate the impact of pyridostigmine in different surgical settings. Registration number: ACTRN12621000530820 (https://anzctr.org.au)., (© The Author(s) 2024. Published by Oxford University Press on behalf of BJS Foundation Ltd. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Background: Cumulative anticholinergic burden refers to the cumulative effect of multiple medications with anticholinergic properties. However, concomitant use of cholinesterase inhibitors (ChEIs) and anticholinergic burden can nullify the benefit of the treatment and worsen Alzheimer's disease (AD). A literature gap exists regarding the extent of the cumulative anticholinergic burden and associated risk factors in AD. Therefore, this study evaluated the prevalence and predictors of cumulative anticholinergic burden among patients with AD initiating ChEIs., Methods: A retrospective longitudinal cohort study was conducted using the Medicare claims data involving parts A, B, and D from 2013 to 2017. The study sample included older adults (65 years and older) diagnosed with AD and initiating ChEIs (donepezil, rivastigmine, or galantamine). The cumulative anticholinergic burden was calculated based on the Anticholinergic Cognitive Burden scale and patient-specific dosing using the defined daily dose over the 1 year follow-up period after ChEI initiation. Incremental anticholinergic burden levels were dichotomized into moderate-high (sum of standardized daily anticholinergic exposure over a year (TSDD) score ≥ 90) versus low-no (score 0-89). The Andersen Behavioral Model was used as the conceptual framework for selecting the predictors under the predisposing, enabling, and need categories. A multivariable logistic regression model was used to evaluate the predictors of high-moderate versus low-no cumulative anticholinergic burden. A multinomial logistic regression model was also used to determine the factors associated with patients having moderate and high burdens compared to low/no burdens., Results: The study included 222,064 older adults with AD with incident ChEI use (mean age 82.24 ± 7.29, 68.9% females, 83.6% White). Overall, 80.48% had some anticholinergic burden during the follow-up, with 36.26% patients with moderate (TSDD scores 90-499), followed by 24.76% high (TSDD score > 500), and 19.46% with low (TSDD score 1-89) burden categories. Predisposing factors such as age; African American, Asian, or Hispanic race; and need factors included comorbidities such as dyslipidemia, syncope, delirium, fracture, pneumonia, epilepsy, and claims-based frailty index were less likely to be associated with the moderate-high anticholinergic burden. The factors that increased the odds of moderate-high burden were predisposing factors such as female sex; enabling factors such as dual eligibility and diagnosis year; and need factors such as baseline burden, behavioral and psychological symptoms of dementia, depression, insomnia, urinary incontinence, irritable bowel syndrome, anxiety, muscle spasm, gastroesophageal reflux disease, heart failure, and dysrhythmia. Most of these findings remained consistent with multinomial logistic regression.  CONCLUSION: Four out of five older adults with AD had some level of anticholinergic burden, with over 60% having moderate-high anticholinergic burden. Several predisposing, enabling, and need factors were associated with the cumulative anticholinergic burden. The study findings suggest a critical need to minimize the cumulative anticholinergic burden to improve AD care., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Adverse drug events (ADEs) rates associated with anti-dementia acetylcholinesterase inhibitors are estimated to be 5%-20% and show a wide range of symptoms. No report has examined whether there is a difference in the anti-dementia drugs' ADEs profile. This study aimed to establish whether anti-dementia drugs' ADEs profile differed. Data was based on the Japanese Adverse Drug Event Report (JADER) database. The reporting odds ratios (RORs) was used to analyze data for ADEs from April 2004-October 2021. The target drugs were donepezil, rivastigmine, galantamine, and memantine. The top ten most frequently occurring adverse events were selected. The association between the RORs and antidementia drug ADEs was evaluated, and compared the distribution rate of expression age related to ADEs and each ADEs' timing of onset due to anti-dementia drugs. The primary outcome was RORs. Secondary outcome were expression age and time-to-onset of ADE associated with anti-dementia drugs. A total of 705,294 reports were analyzed. The adverse events incidence differed. Bradycardia, loss of consciousness, falls, and syncope incidence were significantly diverse. The Kaplan-Meier curve results for the cumulative ADEs incidence showed that donepezil had the slowest onset, while galantamine, rivastigmine, and memantine had approximately the same timing of onset.

Background and Objective: Cholinesterase inhibitors (ChEIs) are used as first-line pharmacotherapy to manage dementia. However, there are limited data regarding their relative safety. This study evaluated the risk of serious adverse events (SAEs) associated with individual ChEIs in older adults with dementia and also examined sex-based and dose-based effects on this risk., Methods: This was a retrospective cohort study using 2013-2015 US Medicare claims data involving Parts A, B, and D. Patients aged ≥ 65 years with a dementia diagnosis and incident use of the ChEIs, namely donepezil, galantamine, or rivastigmine, were included. The primary outcome of interest was SAEs defined as emergency department visits, inpatient hospitalizations, or death within 6 months of ChEI initiation. Multivariable Cox proportional hazards regression with propensity score (PS) as a covariate and inverse probability of treatment weighting generated using generalized boosted models was used to assess the risk of SAEs across individual ChEIs., Results: The study included 767,684 older adults with dementia who were incident new users of ChEIs (donepezil 79.42%, rivastigmine 17.67%, galantamine 2.91%). SAEs were observed in 15.5% of the cohort within 6 months of ChEI prescription. Cox regression model with PS as covariate found that patients prescribed rivastigmine (adjusted hazard ratio [aHR] 1.12; 95% CI 1.03-1.33) and galantamine (aHR 1.51; 95% CI 1.24-1.84) were at increased risk of SAEs compared with patients on donepezil. Stratified analyses revealed that rivastigmine was associated with an 18% increased risk for SAEs in females (aHR 1.18; 95% CI 1.06-1.31), and galantamine was associated with a 71% increased risk in males (aHR 1.71; 95% CI 1.17-2.51) compared with donepezil. High and recommended index doses of rivastigmine and galantamine were associated with an increased risk of SAEs compared with donepezil. The findings were consistent in sensitivity analyses., Conclusion: The study found that the risk of SAEs varied across individual ChEIs, with sex and dose moderating these effects. Therefore, these moderating effects should be carefully considered in personalizing dementia care., (© 2022. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

This retrospective cohort study aimed to evaluate the association between acetylcholinesterase inhibitors (AChEI) usage and the risk of lung cancer. Data from 116,106 new users of AChEI and 348,318, at a ratio of 1:3, matched by age, sex, and index-year, between 2000 and 2015 controls were obtained from the Taiwan Longitudinal Health Insurance Database in this cohort study. The Cox regression model was used to compare the risk of lung cancer. The adjusted hazard ratio (aHR) of lung cancer for AChEI users was 1.198 (95% confidence interval [CI] = 0.765-1.774, p = 0.167). However, the adjusted HR for patients aged ≥ 65 was adjusted to HR: 1.498 (95% CI = 1.124-1.798, p < 0.001), in contrast to the comparison groups. In addition, patients with comorbidities such as pneumonia, bronchiectasis, pneumoconiosis, pulmonary alveolar pneumonopathy, hypertension, stroke, coronary artery disease, diabetes mellitus, chronic kidney disease, depression, anxiety, smoking-related diseases, dementia, and seeking medical help from medical centers and regional hospitals, were associated with a higher risk in lung cancer. Furthermore, longer-term usage of rivastigmine (366-730 days, ≥ 731 days) and galantamine (≥ 731 days) was associated with the risk of lung cancer. AChEI increased the risk of lung cancer in the older aged patients, several comorbidities, and a longer-term usage of rivastigmine and galantamine. Therefore, physicians should estimate the risks and benefits of AChEI usage and avoid prescribing antidepressants concurrently., (© 2022. The Author(s).)

Acetylcholinesterase (AChE) inhibitor is the first choice for the treatment of Alzheimer's disease (AD), but it has some defects, such as dose limitation and unsatisfactory long-term treatment effect. Recent studies have shown that butyrylcholinesterase (BuChE) inhibitors or double acetyl and butyryl cholinesterase inhibitors have better curative effects on AD, and the side effects are lower than those of specific AChE inhibitors. Dual target cholinesterase inhibitors have become a new hotspot in the research of anti-AD drugs. Herein, the synthesis and bioactivities of BuChE inhibitors were reviewed., (Copyright © 2021 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)

Organophosphorus (OP) compounds that inhibit acetylcholinesterase are a common cause of poisoning worldwide, resulting in several hundred thousand deaths each year. The pathways activated during OP compound poisoning via overstimulation of muscarinic acetylcholine receptors (mAChRs) play a decisive role in toxidrome. The antidotal therapy includes atropine, which is a nonspecific blocker of all mAChR subtypes. Atropine is efficient for mitigating depression in respiratory control centers but does not benefit patients with OP-induced skeletal muscle weakness. By using an ex vivo model of OP-induced muscle weakness, we studied the effects of the M1/M4 mAChR antagonist pirenzepine and the M2/M4 mAChR antagonist methoctramine on the force of mouse diaphragm muscle contraction. It was shown that weakness caused by the application of paraoxon can be significantly prevented by methoctramine (1 µM). However, neither pirenzepine (0.1 µM) nor atropine (1 µM) was able to prevent muscle weakness. Moreover, the application of pirenzepine significantly reduced the positive effect of methoctramine. Thus, balanced modulation of neuromuscular synaptic transmission via M1 and M2 mAChRs contributes to paraoxon-induced muscle weakness. It was shown that methoctramine (10 µmol/kg, i.p.) and atropine (50 µmol/kg, i.p.) were equieffective toward increasing the survival of mice poisoned with a 2xLD 50 dose of paraoxon., (© 2022. The Author(s).)

Current myasthenia gravis guidelines recommend intravenous immunoglobulin or plasmapheresis and discontinuation of pyridostigmine during myasthenic crisis. However, intravenous immunoglobulin or plasmapheresis is expensive and frequently not available in developing countries. This study aims to summarize the evidence of giving an acetylcholinesterase inhibitor in myasthenic crisis. Medline, Embase, and Cochrane databases and references were searched for observational studies that determined the use of acetylcholinesterase inhibitor in myasthenic crisis. The eligibility criteria were as follows: population, patients with myasthenic crisis, intervention (acetylcholinesterase inhibitor administration), and outcome (clinical improvement and complications). In total, 106 studies were identified, 92 through database searching (after removing duplicates) and 14 through other sources. Only eight were analyzed in the present systematic review. In five, acetylcholinesterase inhibitor was given at the start of the crisis, whereas in the other three, acetylcholinesterase inhibitor was discontinued initially and then restarted prior to extubation. Two observational analytic studies and three case reports showed improvement in different outcome measures. In the other three, improvement of outcome measures was also observed. Overall, a small proportion of patients developed cardiac arrhythmia and pneumonia after administration of acetylcholinesterase inhibitor alone, although this was not statistically different compared with those subjected to plasmapheresis. In summary, continuous intravenous infusion of pyridostigmine or neostigmine can be a substitute for intravenous immunoglobulin or plasmapheresis if these are not available during crisis; however, caution should be observed because of the aforementioned possible complications., (© 2021. Springer Science+Business Media, LLC, part of Springer Nature and Neurocritical Care Society.)

Objective: To evaluate the association between the use of antipsychotic drugs and cholinesterase inhibitors and the risk of falls and fractures in elderly patients with major neurocognitive disorders., Design: Self-controlled case series., Setting: Taiwan's National Health Insurance Database., Participants: 15 278 adults, aged ≥65, with newly prescribed antipsychotic drugs and cholinesterase inhibitors, who had an incident fall or fracture between 2006 and 2017. Prescription records of cholinesterase inhibitors confirmed the diagnosis of major neurocognitive disorders; all use of cholinesterase inhibitors was reviewed by experts., Main Outcome Measures: Conditional Poisson regression was used to derive incidence rate ratios and 95% confidence intervals for evaluating the risk of falls and fractures for different treatment periods: use of cholinesterase inhibitors alone, antipsychotic drugs alone, and a combination of cholinesterase inhibitors and antipsychotic drugs, compared with the non-treatment period in the same individual. A 14 day pretreatment period was defined before starting the study drugs because of concerns about confounding by indication., Results: The incidence of falls and fractures per 100 person years was 8.30 (95% confidence interval 8.14 to 8.46) for the non-treatment period, 52.35 (48.46 to 56.47) for the pretreatment period, and 10.55 (9.98 to 11.14), 10.34 (9.80 to 10.89), and 9.41 (8.98 to 9.86) for use of a combination of cholinesterase inhibitors and antipsychotic drugs, antipsychotic drugs alone, and cholinesterase inhibitors alone, respectively. Compared with the non-treatment period, the highest risk of falls and fractures was during the pretreatment period (adjusted incidence rate ratio 6.17, 95% confidence interval 5.69 to 6.69), followed by treatment with the combination of cholinesterase inhibitors and antipsychotic drugs (1.35, 1.26 to 1.45), antipsychotic drugs alone (1.33, 1.24 to 1.43), and cholinesterase inhibitors alone (1.17, 1.10 to 1.24)., Conclusions: The incidence of falls and fractures was high in the pretreatment period, suggesting that factors other than the study drugs, such as underlying diseases, should be taken into consideration when evaluating the association between the risk of falls and fractures and use of cholinesterase inhibitors and antipsychotic drugs. The treatment periods were also associated with a higher risk of falls and fractures compared with the non-treatment period, although the magnitude was much lower than during the pretreatment period. Strategies for prevention and close monitoring of the risk of falls are still necessary until patients regain a more stable physical and mental state., Competing Interests: Competing interests: All authors have completed the ICMJE uniform disclosure form at www.icmje.org/disclosure-of-interest/ and declare: EC-CL reports grants from the Ministry of Science and Technology of Taiwan (107-2320-B-006-070-MY3 and 106-2320-B-006-025-MY2), outside the submitted work; KK-CM reports grants from the CW Maplethorpe Fellowship, National Institute of Health Research, UK, and the European Commission Horizon 2020 Framework, personal fees from IQVIA, and grants from Amgen and GlaxoSmithKline, outside the submitted work; no financial relationships with any organisations that might have an interest in the submitted work in the previous three years; no other relationships or activities that could appear to have influenced the submitted work., (© Author(s) (or their employer(s)) 2019. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Acetylcholinesterase inhibitors (AChEIs) have been associated with an increased risk of starting antimuscarinic treatment to treat overactive bladder (OAB)-an example of a prescribing cascade. Limited comparative data exist regarding the prescribing cascade of antimuscarinics across individual AChEIs in older adults with dementia., Objective: This study examined the association between individual AChEI use and antimuscarinic cascade in older adults with dementia., Methods: We conducted a new user retrospective cohort study from January 2005 to December 2018 using data from the TriNetX electronic medical record database, a federated electronic medical records network in the US. The cohort included patients 65 years or older with a diagnosis of dementia using AChEIs (donepezil, galantamine, or rivastigmine). Individual AChEIs were identified with index dates from 1 January 2006 to 31 June 2018, with a 1-year washout period. The study excluded patients with any antimuscarinic use and OAB diagnosis 1 year before the AChEI index date. The primary outcome of interest was the prescription of antimuscarinics within 6 months of the AChEI index date. A Cox proportional hazard model was used to assess the association between individual incident AChEI use and antimuscarinic prescribing cascade after controlling for several covariates., Results: The study included 47,059 older adults with dementia who were incident users of AChEIs. Most of these patients were initiated with donepezil (83.1%), followed by rivastigmine (12.3%) and galantamine (4.6%). Overall, 8.16% of the study cohort had incident OAB diagnosis or antimuscarinic prescription. Antimuscarinics were initiated by 1725 (3.7%) older adults with dementia within 6 months of AChEI prescription, and cascade varied widely across individual agents-donepezil (3.9%), rivastigmine (2.6%), and galantamine (2.9%). Cox proportional hazard analyses revealed that donepezil users had an increased risk of receiving antimuscarinics (adjusted hazard ratio 1.55, 95% confidence interval 1.31-1.83) compared with rivastigmine. The findings were consistent in sensitivity analyses., Conclusion: This study found that donepezil use is more likely to lead to antimuscarinic cascade than rivastigmine. Future studies are needed to determine the potential consequences of this cascade in dementia.

Introduction : Alzheimer's disease and depression are health conditions affecting millions of people around the world. Both are strongly related to the level of the neurotransmitter acetylcholine. Since cholinergic deficit is characteristic of Alzheimer's disease, acetylcholinesterase inhibitors are applied as relevant drugs for the treatment of this disease, elevating the level of acetylcholine. On the other hand, a high level of acetylcholine is found to be associated with the symptoms of clinical depression. Areas covered : This article aims to discuss if acetylcholinesterase inhibitors used as anti-Alzheimer's drugs could be the cause of the symptoms of clinical depression often linked to this neurological disorder. Emphasis will be put on drugs currently in use and on newly investigated natural products, which can inhibit AChE activity. Expert opinion : Currently, it is not proven that the patient treated for Alzheimer's disease is prone to increased risk for depression due to the acetylcholinesterase inhibition, but there are strong indications. The level of acetylcholine is not the only factor in highly complicated diseases like AD and depression. Still, it needs to be considered isolated, keeping in mind the nature of presently available therapy, especially during a rational drug design process.

Donepezil, an inhibitor for acetylcholinesterase used for patients with Alzheimer's disease, has been shown to inhibit I Kr , occasionally inducing torsade de pointes. In order to analyze the causal relationship between donepezil treatment and onset of lethal arrhythmias, we initially assessed electropharmacological effects of donepezil hydrochloride of 0.01, 0.1, and 1 mg/kg, i.v. over 10 min using the halothane-anesthetized intact dogs (n = 4), possibly providing subtherapeutic to supratherapeutic plasma concentrations. Although the low or middle dose did not exert any effect, the high dose transiently increased the ventricular refractoriness along with modest prolongation of the late repolarization period, indicating potential I Kr inhibitory action in vivo. Moreover, the high dose induced the positive chronotropic, inotropic, and dromotropic actions along with the pressor effect and prolongation of early repolarization period, suggesting sympathicotonic condition in the central nervous system. Next, we examined proarrhythmic effects of donepezil hydrochloride of 0.1 and 1 mg/kg, i.v. over 10 min using the conscious chronic atrioventricular block dogs (n = 4). Although the low dose hardly affected the cardiovascular variables, the high dose increased the atrial and ventricular rate without significantly altering the repolarization period, possibly reflecting sympathicotonic condition. Importantly, the high dose induced non-sustained ventricular tachycardia in half of the animals. Thus, donepezil by itself did not induce torsade de pointes in vivo, which suggests that donepezil-induced sympathicotonic condition may induce Ca 2+ overload, triggering the ventricular arrhythmias, but might indirectly attenuate its I Kr inhibitory action, preventing excessive repolarization delay.

The recent use of organophosphate nerve agents in Syria, Malaysia, Russia, and the United Kingdom has reinforced the potential threat of their intentional release. These agents act through their ability to inhibit human acetylcholinesterase (hAChE; E.C. 3.1.1.7), an enzyme vital for survival. The toxicity of hAChE inhibition via G-series nerve agents has been demonstrated to vary widely depending on the G-agent used. To gain insight into this issue, the structures of hAChE inhibited by tabun, sarin, cyclosarin, soman, and GP were obtained along with the inhibition kinetics for these agents. Through this information, the role of hAChE active site plasticity in agent selectivity is revealed. With reports indicating that the efficacy of reactivators can vary based on the nerve agent inhibiting hAChE, human recombinatorially expressed hAChE was utilized to define these variations for HI-6 among various G-agents. To identify the structural underpinnings of this phenomenon, the structures of tabun, sarin, and soman-inhibited hAChE in complex with HI-6 were determined. This revealed how the presence of G-agent adducts impacts reactivator access and placement within the active site. These insights will contribute toward a path of next-generation reactivators and an improved understanding of the innate issues with the current reactivators.

Background: Vascular cognitive impairment (VCI) describes a broad spectrum of cognitive impairments caused by cerebrovascular disease, ranging from mild cognitive impairment to dementia. There are currently no pharmacological treatments recommended for improving either cognition or function in people with VCI. Three cholinesterase inhibitors (donepezil, galantamine, and rivastigmine) are licenced for the treatment of dementia due to Alzheimer's disease. They are thought to work by compensating for reduced cholinergic neurotransmission, which is also a feature of VCI. Through pairwise comparisons with placebo and a network meta-analysis, we sought to determine whether these medications are effective in VCI and whether there are differences between them with regard to efficacy or adverse events., Objectives: (1) To assess the efficacy and safety of cholinesterase inhibitors in the treatment of adults with vascular dementia and other VCI. (2) To compare the effects of different cholinesterase inhibitors on cognition and adverse events, using network meta-analysis., Search Methods: We searched ALOIS, the Cochrane Dementia and Cognitive Improvement Group's register, MEDLINE (OvidSP), Embase (OvidSP), PsycINFO (OvidSP), CINAHL (EBSCOhost), Web of Science Core Collection (ISI Web of Science), LILACS (BIREME), ClinicalTrials.gov, and the World Health Organization International Clinical Trials Registry Platform on 19 August 2020., Selection Criteria: We included randomised controlled trials in which donepezil, galantamine, or rivastigmine was compared with placebo or in which the drugs were compared with each other in adults with vascular dementia or other VCI (excluding cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL)). We included all drug doses and routes of administration., Data Collection and Analysis: Two review authors independently identified eligible trials, extracted data, assessed risk of bias, and applied the GRADE approach to assess the certainty of the evidence. The primary outcomes were cognition, clinical global impression, function (performance of activities of daily living), and adverse events. Secondary outcomes were serious adverse events, incidence of development of new dementia, behavioural disturbance, carer burden, institutionalisation, quality of life and death. For the pairwise analyses, we pooled outcome data at similar time points using random-effects methods. We also performed a network meta-analysis using Bayesian methods., Main Results: We included eight trials (4373 participants) in the review. Three trials studied donepezil 5 mg or 10 mg daily (n= 2193); three trials studied rivastigmine at a maximum daily dose of 3 to 12 mg (n= 800); and two trials studied galantamine at a maximum daily dose of 16 to 24 mg (n= 1380). The trials included participants with possible or probable vascular dementia or cognitive impairment following stroke. Mean ages were between 72.2 and 73.9 years. All of the trials were at low or unclear risk of bias in all domains, and the evidence ranged from very low to high level of certainty. For cognition, the results showed that donepezil 5 mg improves cognition slightly, although the size of the effect is unlikely to be clinically important (mean difference (MD) -0.92 Alzheimer's Disease Assessment Scale-Cognitive Subscale (ADAS-Cog) points (range 0 to 70), 95% confidence interval (CI) -1.44 to -0.40; high-certainty evidence). Donepezil 10 mg (MD -2.21 ADAS-Cog points, 95% CI -3.07 to -1.35; moderate-certainty evidence) and galantamine 16 to 24 mg (MD -2.01 ADAS-Cog point, 95%CI -3.18 to -0.85; moderate-certainty evidence) probably also improve cognition, although the larger effect estimates still may not be clinically important. With low certainty, there may be little to no effect of rivastigmine 3 to 12 mg daily on cognition (MD 0.03 ADAS-Cog points, 95% CI -3.04 to 3.10; low-certainty evidence). Adverse events reported in the studies included nausea and/or vomiting, diarrhoea, dizziness, headache, and hypertension. The results showed that there was probably little to no difference between donepezil 5 mg and placebo in the number of adverse events (odds ratio (OR) 1.22, 95% CI 0.94 to 1.58; moderate-certainty evidence), but there were slightly more adverse events with donepezil 10 mg than with placebo (OR 1.95, 95% CI 1.20 to 3.15; high-certainty evidence). The effect of rivastigmine 3 to 12 mg on adverse events was very uncertain (OR 3.21, 95% CI 0.36 to 28.88; very low-certainty evidence). Galantamine 16 to 24 mg is probably associated with a slight excess of adverse events over placebo (OR 1.57, 95% CI 1.02 to 2.43; moderate-certainty evidence). In the network meta-analysis (NMA), we included cognition to represent benefit, and adverse events to represent harm. All drugs ranked above placebo for cognition and below placebo for adverse events. We found donepezil 10 mg to rank first in terms of benefit, but third in terms of harms, when considering the network estimates and quality of evidence. Galantamine was ranked second in terms of both benefit and harm. Rivastigmine had the lowest ranking of the cholinesterase inhibitors in both benefit and harm NMA estimates, but this may reflect possibly inadequate doses received by some trial participants and small trial sample sizes., Authors' Conclusions: We found moderate- to high-certainty evidence that donepezil 5 mg, donepezil 10 mg, and galantamine have a slight beneficial effect on cognition in people with VCI, although the size of the change is unlikely to be clinically important. Donepezil 10 mg and galantamine 16 to 24 mg are probably associated with more adverse events than placebo. The evidence for rivastigmine was less certain. The data suggest that donepezil 10 mg has the greatest effect on cognition, but at the cost of adverse effects. The effect is modest, but in the absence of any other treatments, people living with VCI may still wish to consider the use of these agents. Further research into rivastigmine is needed, including the use of transdermal patches., (Copyright © 2021 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.)

In recent years, the number of patients with Alzheimer's type dementia continues to increase year by year. As a first-line drug, cholinesterase inhibitor is used. There is a close relationship between the time course of the drug plasma concentration (pharmacokinetics; PK) and the time course of its effects and side effects (pharmacodynamics; PD). However, the relationship between PK and PD is not simply that plasma concentrations are proportional to the effects. The effect is expressed through the characteristics of various pharmacokinetic processes. Therefore, it is important to investigate the transition of effects accompanying its pharmacokinetics. We conducted a fundamental PK/PD analysis using donepezil. Time course of acetylcholine in the hippocampus was investigated with relation to its PK after donepezil administration using rats. The PK and PD characteristics of the drug, including its active metabolite, were investigated. Additionally, Alzheimer's type dementia drugs are often given in combination with antiplatelet drugs such as cilostazol. It is reported that donepezil and cilostazol interact clinically, partly due to inhibition in the efflux transporters in certain tissues. There are various transporters in the body, and interactions through them may cause unexpected changes in the effects. So, it is important to calculate the correlation between the donepezil level in plasma and tissues after their combined administration. From the PK/PD point of view, the results of this study will provide insight into the time course of effects and the characteristics of drug-drug interaction in clinical practice.

Background: Pneumonia is an inflammatory condition induced by infection of the lungs and is frequently a cause of morbidity and mortality among patients with Alzheimer's disease (AD). Some studies have shown an association between acetylcholinesterase inhibitor use and elevated pneumonia risk., Objective: The purpose of this study was to perform a comparative analysis of the number of reported pneumonia cases in individuals prescribed rivastigmine relative to the number of reported cases by patients using other therapeutics including over-the-counter drugs and other AD therapeutics, as reported to the FDA Adverse Event Reporting System (FAERS) database., Methods: A disproportionality analysis was conducted to investigate the association between using rivastigmine and risk of pneumonia. Age, gender, dosage, temporality, and geographic distribution of reported cases were also assessed., Results: Patients prescribed rivastigmine were more likely to report pneumonia as an adverse event than many drugs except galantamine. Males were found to be 46% more likely than females to report pneumonia as an adverse event while likelihood of pneumonia diagnosis increases 3-5-fold in patients older than 65 years of age., Conclusion: The observed elevated frequency of aspiration pneumonia in patients prescribed rivastigmine may be due to an induced cholinergic crisis that is selective for the medulla oblongata, resulting in gastrointestinal distress, impaired swallowing, heightened salivation, and labored breathing. The observed elevated frequency of infectious pneumonia in patients prescribed rivastigmine may also be linked to overstimulation of neurons in the medulla oblongata and downstream suppression of localized inflammatory responses.

Background: Bradycardia is a physiological condition characterized by a decrease in heart rate and is a side effect of many drug classes. Bradycardia has been reported as an adverse event for patients receiving donepezil for Alzheimer's disease (AD) treatment., Objective: The purpose of the paper is to systematically investigate the association between the occurrence of bradycardia in adults and the usage of donepezil using clinical data derived from the FDA Adverse Event Reporting System (FAERS) database., Methods: The risk of bradycardia in patients who only took donepezil was compared with those of patients who only took over-the-counter medications, multiple arrhythmia drugs, or other medications for AD treatment. In addition, this study sought to determine if this heightened bradycardia risk was influenced by sex, age, and dosage., Results: The results indicated that there was a significant greater likelihood of reporting bradycardia in patients administered donepezil than most of the drugs investigated. There was no significant association between age or the dosage of donepezil and the likelihood of reporting bradycardia. However, males were found to be more likely than females to report bradycardia as an adverse event. Tumor necrosis factor inhibition and the stimulation of endothelial nitric oxide synthase were proposed to be the primary mechanism of actions which confer elevated bradycardia risk when using donepezil., Conclusion: These findings identified strong association between the usage of donepezil and bradycardia in adults as well as provided insight into the underlying molecular mechanisms that induce bradycardia by donepezil.

For over three-quarters of a century, organophosphorus (OP) insecticides have been ubiquitously used in agricultural, residential, and commercial settings and in public health programs to mitigate insect-borne diseases. Their broad-spectrum insecticidal effectiveness is accounted for by the irreversible inhibition of acetylcholinesterase (AChE), the enzyme that catalyzes acetylcholine (ACh) hydrolysis, in the nervous system of insects. However, because AChE is evolutionarily conserved, OP insecticides are also toxic to mammals, including humans, and acute OP intoxication remains a major public health concern in countries where OP insecticide usage is poorly regulated. Environmental exposures to OP levels that are generally too low to cause marked inhibition of AChE and to trigger acute signs of intoxication, on the other hand, represent an insidious public health issue worldwide. Gestational exposures to OP insecticides are particularly concerning because of the exquisite sensitivity of the developing brain to these insecticides. The present article overviews and discusses: (i) the health effects and therapeutic management of acute OP poisoning during pregnancy, (ii) epidemiological studies examining associations between environmental OP exposures during gestation and health outcomes of offspring, (iii) preclinical evidence that OP insecticides are developmental neurotoxicants, and (iv) potential mechanisms underlying the developmental neurotoxicity of OP insecticides. Understanding how gestational exposures to different levels of OP insecticides affect pregnancy and childhood development is critical to guiding implementation of preventive measures and direct research aimed at identifying effective therapeutic interventions that can limit the negative impact of these exposures on public health., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

A series of novel quinolinone derivatives bearing dithiocarbamate moiety were designed and synthesised as multifunctional AChE inhibitors for the treatment of AD. Most of these compounds exhibited strong and clearly selective inhibition to ee AChE. Among them, compound 4c was identified as the most potent inhibitor to both ee AChE and h AChE (IC 50 = 0.22 μM for eeAChE; IC 50 = 0.16 μM for h AChE), and it was also the best inhibitor to AChE-induced Aβ aggregation (29.02% at 100 μM) and an efficient inhibitor to self-induced Aβ aggregation (30.67% at 25 μM). Kinetic and molecular modelling studies indicated that compound 4c was a mixed-type inhibitor, which could interact simultaneously with the catalytic anionic site (CAS) and the peripheral anionic site (PAS) of AChE. In addition, 4c had good ability to cross the BBB, showed no toxicity on SH-SY5Y neuroblastoma cells and was well tolerated in mice at doses up to 2500 mg/kg (po).

Eighty consecutive Chinese patients diagnosed with Alzheimer disease were assessed for darkening of grey hair. Of the 62 eligible patients (mean age = 79.3 ± 7.9 years; male: female = 1:1.48), 24/62 (38.7%, 95%CI: 26.6 - 51.9) reported hair darkening after prolonged usage of cholinesterase inhibitor for at least 6 months. Of the 24 patients with hair darkening, 17 (70.9%) experienced hair darkening in the occipital region, 3 (12.5%) in the parietal region, 2 (8.3%) patients in the frontal region and 2 (8.3%) patients experienced hair darkening in multiple regions. Analysis of melanin concentration showed no significant difference between darkened hair of patients after prolonged drug use and the dark hair of controls (P = 0.381)., (© 2020 The Australasian College of Dermatologists.)

Objectives: The risk of diabetes mellitus may be elevated among persons exposed to some pesticides, including cholinesterase-inhibiting insecticides (organophosphates and carbamates). The objective of this study was to investigate how acetylcholinesterase activity was associated with mean blood glucose levels among smallholder farmers in Uganda., Methods: We conducted a short-term follow-up study among 364 smallholder farmers in Uganda. Participants were examined three times from September 2018 to February 2019. At each visit, we measured glycosylated haemoglobin A (HbA 1c ) as a measure of long-term average blood glucose levels. Exposure to organophosphate and carbamate insecticides was quantified using erythrocyte acetylcholinesterase normalised by haemoglobin (AChE/Hb). For a subgroup of participants, fasting plasma glucose (FPG) was also available. We analysed HbA 1c and FPG versus AChE/Hb in linear mixed and fixed effect models adjusting for age, sex, physical activity level, and consumption of fruits and vegetables, alcohol and tobacco., Results: Contrary to our hypothesis, our mixed effect models showed significant correlation between low AChE/Hb and low HbA 1c . Adjusted mean HbA 1c was 0.74 (95% CI 0.17 to 1.31) mmol/mol lower for subjects with AChE/Hb=24.3 U/g (35th percentile) compared with subjects with AChE/Hb=25.8 U/g (50th percentile). Similar results were demonstrated for FPG. Fixed effect models showed less clear correlations for between-phase changes in AChE/Hb and HbA 1c ., Conclusions: Our results do not clearly support a causal link between exposure to cholinesterase-inhibiting insecticides and elevated blood glucose levels (expressed as HbA 1c and FPG), but results should be interpreted with caution due to the risk of reverse causality., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2020. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Donepezil is an acetylcholinesterase inhibitor commonly used to treat mild to moderate Alzheimer's disease. Its use has been associated with increased bone mass in humans and animals. However, the effect of postoperative administration of donepezil on bone healing remains unknown. Therefore, this study aimed to assess the impact of postoperative injection of donepezil on bone healing, titanium-implant osseointegration, and soft tissue healing. Twenty-two Sprague-Dawley rats were randomly assigned to receive a daily dose of either donepezil (0.6 mg/kg) or saline as a control. In each rat, a uni-cortical defect was created in the right tibia metaphysis and a custom-made titanium implant was placed in the left tibiae. After two weeks, rats were euthanized, and their bones were analysed by Micro-CT and histology. The healing of bone defect and implant osseointegration in the rats treated with donepezil were significantly reduced compared to the saline-treated rats. Histomorphometric analysis showed lower immune cell infiltration in bone defects treated with donepezil compared to the saline-treated defects. On the other hand, the healing time of soft tissue wounds was significantly shorter in donepezil-treated rats compared to the controls. In conclusion, short-term administration of donepezil hinders bone healing whereas enhancing soft tissue healing.

Acetylcholinesterase is an important biochemical enzyme in that it controls acetylcholine-mediated neuronal transmission in the central nervous system, contains a unique structure with two binding sites connected by a gorge region, and it has historically been the main pharmacological target for treatment of Alzheimer's disease. Given the large projected increase in Alzheimer's disease cases in the coming decades and its complex, multifactorial nature, new drugs that target multiple aspects of the disease at once are needed. Tacrine, the first acetylcholinesterase inhibitor used clinically but withdrawn due to hepatotoxicity concerns, remains an important starting point in research for the development of multitarget-directed acetylcholinesterase inhibitors. This review highlights tacrine-based, multitarget-directed acetylcholinesterase inhibitors published in the literature since 2015 with a specific focus on merged compounds (i.e., compounds where tacrine and a second pharmacophore show significant overlap in structure). The synthesis of these compounds from readily available starting materials is discussed, along with acetylcholinesterase inhibition data, relative to tacrine, and structure activity relationships. Where applicable, molecular modeling, to elucidate key enzyme-inhibitor interactions, and secondary biological activity is highlighted. Of the numerous compounds identified, there is a subset with promising preliminary screening results, which should inspire further development and future research in this field.

Non-depolarizing neuromuscular blocking agents are used during general anesthesia to facilitate intubation and optimize surgical conditions. When patients leave the operating room after surgery, postoperative residual neuromuscular block occurs frequently, increasing vulnerability to respiratory complications such as hypoxemia and unplanned postoperative mechanical ventilation. To restore neuromuscular transmission and skeletal muscle strength, anesthesiologists typically administer peripherally acting acetylcholinesterase inhibitors such as neostigmine. However, neostigmine's desirable effects have a narrow therapeutic range. Even at recommended dose (15-50 μg/kg), neostigmine induces nicotinic (upper airway muscle weakness leading to dysphagia and upper airway obstruction, and decreased maximum inspiratory airflow) and muscarinic (blurred vision, bronchial constriction, abdominal cramping and nausea) side effects. Recent data have questioned as to whether neostigmine reversal of neuromuscular blockade improves relevant patient outcomes such as postoperative respiratory and perioperative cardiovascular complications. A central strategy to avoid side effects of neuromuscular blocking agents is their judicious use based on quantitative monitoring of neuromuscular transmission using repetitive peripheral nerve stimulation (train-of-four ratio). Peripherally acting acetylcholinesterase inhibitors such as neostigmine should then only be administered when indicated and dosed based on results of the train-of-four ratio., Competing Interests: Declaration of competing interest All other authors declare no conflict of interest., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Donepezil, galantamine, and rivastigmine are the three acetylcholinesterase inhibitors (AChEIs), out of a total of only four medications prescribed in the treatment of Alzheimer's Disease (AD) and related dementias. These medications are known to be associated with bradycardia given their mechanism of action of increasing acetylcholine (ACh). However, in March 2015, donepezil was added to the CredibleMeds "known-risk" category, a list where medications have a documented risk for acquired long-QT syndrome (ALQTS) and torsades de pointes (TdP) - a malignant ventricular arrhythmia that is a different adverse event than bradycardia (and is not necessarily associated with ACh action). The purpose of this article is to review the three AChEIs, especially with regards to mechanistic differences that may explain why only donepezil poses this risk; several pharmacological mechanisms may explain why. However, from an empirical point-of-view, aside from some case-reports, only a limited number of studies have generated relevant information regarding AChEIs' and electrocardiogram findings; none have specifically compared donepezil against galantamine or rivastigmine for malignant arrhythmias such as TdP. Currently, the choice of one of the three AChEIs for treatment of AD symptoms is primarily dependent upon clinician and patient preference. However, clinicians should be aware of the potential increased risk associated with donepezil. There is a need to examine the comparative risk of malignant arrhythmias among AChEIs users in real-world practice; this may have important implications with regards to changes in AChEI prescribing patterns., (© 2020 The Authors. Pharmacology Research & Perspectives published by John Wiley & Sons Ltd, British Pharmacological Society and American Society for Pharmacology and Experimental Therapeutics.)

Objectives: Alzheimer's disease (AD) is one of the most prevalent neurodegenerative disorders and a well-recognized cause of dementia with ageing. In this review, we have represented the ChE and MAO inhibitory potential of TV 3326 against AD based on current scientific evidence., Key Findings: The aetiology of AD is quite complex and not completely understood. However, it has been observed that AD involves the deposition of abnormal amyloid beta (Aβ), along with hyperphosphorylation of tau, oxidative stress, low acetylcholine (ACh) level and biometal dyshomeostasis. Due to the complex nature of AD aetiology, active research is required in the areas of development of multitarget drugs with 2 or more complementary biological functions, as they might represent significant progress in the AD treatment. Interestingly, it has been found that TV 3326 (i.e. ladostigil) is regarded as a novel therapeutic agent since it has the potential to cause inhibition of monoamine oxidase (MAO) A and B, and acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) in the brain. Furthermore, it has the capacity to reverse memory impairments, which further suggests the ability of this drug to elevate cholinergic activity in the brain., Summary: TV 3326 can avert oxidative-nitrative stress and gliosis. It has also been confirmed that TV 3326 contains neuroprotective and anti-apoptotic properties. Therefore, this distinctive combined inhibition of ChE and MAO along with its neuroprotective property makes TV 3326 a useful drug in the treatment of AD., (© 2020 Royal Pharmaceutical Society.)

A series of new tetrahydroacridine and 3,5-dichlorobenzoic acid hybrids with different spacers were designed, synthesized, and evaluated for their ability to inhibit both cholinesterase enzymes. Compounds 3a , 3b , 3f , and 3g exhibited selective butyrylcholinesterase ( Eq BuChE) inhibition with IC 50 values ranging from 24 to 607 nM. Among them, compound 3b was the most active (IC 50 = 24 nM). Additionally, 3c (IC 50 for Ee AChE = 25 nM and IC 50 for Eq BuChE = 123 nM) displayed dual cholinesterase inhibitory activity and was the most active compound against acetylcholinesterase (AChE). Active compound 3c was also tested for the ability to inhibit Aβ aggregation. Theoretical physicochemical properties of the compounds were calculated using ACD Labs Percepta and Chemaxon. A Lineweaver-Burk plot and docking study showed that 3c targeted both the catalytic active site (CAS) and the peripheral anionic site (PAS) of AChE. Moreover, 3c appears to possess neuroprotective activity and could be considered a free-radical scavenger. In addition, 3c did not cause DNA damage and was found to be less toxic than tacrine after oral administration; it also demonstrated little inhibitory activity towards hyaluronidase (HYAL), which may indicate that it possesses anti-inflammatory properties. The screening for new in vivo interactions between 3c and known receptors was realized by yeast three-hybrid technology (Y3H).

Background: Pisa syndrome (PS) is characterized by an abnormally sustained posture, with flexion of the body and head to one side and slight rotation of the trunk. Although PS most commonly arises as an adverse effect of antipsychotic drugs, choline-esterase inhibitors (ChEIs) are also sometimes known to induce PS. Despite the fact that the precise mechanism remains unclear, cholinergic-dopaminergic imbalance has been considered as a possible pathophysiologic mechanism underlying the genesis of PS., Case Presentation: We hereby report the case of a 60-year-old woman with Alzheimer's disease who presented with the signs of PS after her treatment was switched to galantamine, a type of ChEI, even though she had received donepezil, another type of ChEI, for 5 years without any complications. To the best of our knowledge, this is the first report of PS associated with treatment switch from one to another type of ChEI. Galantamine, but not other ChEIs, can enhance striatal dopamine release through allosteric modulation of the nicotinic acetylcholine receptor, and has weaker muscarinic effects than donepezil. Therefore, we propose two novel hypotheses to explain the development of PS, as follows; galantamine, which enhances dopamine release, can induce imbalance of dopamine levels in the striatum of patients with dementia, resulting in PS, and the weaker muscarinic effects of the drug could be one of the factors predisposing to the development of PS., Conclusion: The present case suggests that treatment with galantamine is associated with a higher risk of development of PS than that with other ChEIs, such as donepezil, despite the pharmacological profile of galantamine as a dopamine modulator. Also, this report provides novel insight into another plausible mechanism underlying the development of PS, besides cholinergic-dopaminergic imbalance, namely, dopamine imbalance in the striatum with muscarinic-nicotinic imbalance.

This pilot study designed to evaluate the efficacy and safety of MAO-B inhibitor in comparison with Donepezil (DNP) in elderly Chinese patients with Alzheimer disease (AD). In the present clinical trial, Chinese elderly patients aged ≥65 years with a confirmed diagnosis of AD were enrolled. The patients received MAO-B inhibitor (Selegiline 5 mg) or DNP 10 mg daily (reference) for 6 months. The efficacy and safety data were collected from 120 patients (60 patients in each group) every 3 weeks until 6 months. The primary endpoints were to assess the change in cognitive score from baseline in both the treatment group. The result of the present study showed that the patients treated with MAO-B inhibitor and DNP have similar efficacy and safety profile Considering the clinical benefit, mean (SD) improvement in sign and symptoms was numerically greater in DNP-treated patients as compared to MAO-B inhibitor at endpoint visit (SIB: 12.3 (3.7) vs 11.3 (4.2); AD severity: 14.2 (3.5); CIBIS+/CIBIC: 10.2 (2.7) vs 9.4 (3.2); ADCS-ADL: 14.3 (4.2) vs 13.2 (3.4); MMSE: 14.3 (3.7) vs 12.2 (3.2), P>0.05 respectively for each comparison). However, a statistical difference in terms of clinical benefit was similar between both the treatment groups (p>0.05). Overall, both the study drugs were found comparable in relieving the symptoms of AD (severity score after end of treatment: 14.2 vs 13.4 respectively; p >0.05). This indicates that MAO-B inhibitor is a potential target for the treatment of AD in China. The results of the present study may help to design a large clinical trial to evaluate the efficacy and safety of MAO-B inhibitor in comparison with DNP in AD patients.

Introduction: We evaluated the impact of deprescribing acetylcholinesterase inhibitors (AChEIs) on aggressive behaviors and incident antipsychotic use in nursing home (NH) residents with severe dementia., Methods: We conducted a retrospective study of Medicare claims, Part D, Minimum Data Set for NH residents aged 65+ with severe dementia receiving AChEIs in 2016. Aggressive behaviors were measured using the aggressive behavior scale (ABS; n = 30,788). Incident antipsychotic prescriptions were evaluated among antipsychotic non-users (n = 25,188). Marginal structural models and inverse probability of treatment weights were used to evaluate associations of AChEI deprescribing and outcomes., Results: The severity of aggressive behaviors was low at baseline (mean ABS = 0.5) and was not associated with deprescribing AChEIs (0.002 increase in ABS, P = .90). Incident antipsychotic prescribing occurred in 5.1% of residents and was less likely with AChEI deprescribing (adjusted odds ratio = 0.52 [0.40-0.68], P <.001])., Discussion: Deprescribing AChEIs was not associated with a worsening of aggressive behaviors or incident antipsychotic prescriptions., (© 2020 the Alzheimer's Association.)

Background/objective: Reevaluation of the appropriateness of acetylcholinesterase inhibitors (AChEIs) is recommended in older adults with severe dementia, given the lack of strong evidence to support their continued effectiveness and risk for medication-induced adverse events. We sought to evaluate the impact of deprescribing AChEIs on risk of all-cause events (hospitalizations, emergency department visits, and mortality) and serious falls or fractures in older nursing home (NH) residents with severe dementia., Design: Analysis of 2015 to 2016 data from Medicare claims, Part D prescriptions, Minimum Data Set (MDS) version 3.0, Area Health Resource File, and Nursing Home Compare. Marginal structural models with inverse probability of treatment weights were used to evaluate the association of deprescribing AChEIs and all-cause negative events as well as serious falls or fractures., Setting: US Medicare-certified NHs., Participants: Nonskilled NH residents, aged 65 years and older, with severe dementia receiving AChEIs within the first 14 days of an MDS assessment in 2016 (n = 37 106)., Results: The sample was primarily white (78.7%), female (75.5%), and aged 80 years or older (77.4%). Deprescribing AChEIs was associated with an increased likelihood of all-cause negative events in unadjusted models (odds ratio [OR] = 1.17; 95% confidence interval [CI] = 1.11-1.23; P < .01), but not in fully adjusted models (adjusted OR [aOR] = 1.00; 95% CI = 0.94-1.06; P = .94). By contrast, deprescribing was associated with a reduced likelihood of serious falls or fractures in unadjusted models (OR = 0.59; 95% CI = 0.52-0.66; P < .001) and remained significant in adjusted models (aOR = 0.64; 95% CI = 0.56-0.73; P < .001)., Conclusion: Deprescribing AChEIs was not associated with a significant increase in the likelihood for all-cause negative events and was associated with a reduced likelihood of falls and fractures in older NH residents with dementia. Our findings suggest that deprescribing AChEIs is a reasonable approach to reduce the risk of serious falls or fractures without increasing the risk for all-cause events. J Am Geriatr Soc 68:699-707, 2020., (© 2019 The American Geriatrics Society.)

Background: Antidementia drugs (cholinesterase inhibitors and memantine) are still widely prescribed despite their controversial effects and 2011 guidelines that no longer encourage their prescription. The objective was to assess which factors remained determinants of antidementia drug prescriptions., Methods: A cross-sectional study was performed in 2013. Patients suffering from dementia, aged 65 and over, identified in the French national health insurance database were included. Because we anticipated a high correlation between age, comorbidities, and health care use, we first identified the patients' health status by a latent class analysis. Second, we performed adjusted logistic regression models. The explanatory variables were patients' health status, gender, prescription of nonpharmacological treatments (physical and speech therapies), prescription of psychotropic drugs, and access to health care., Results: Among the 3873 patients included, 38% received antidementia drugs. Three latent classes of patients with different health status were identified. Patients with poor health status received significantly fewer antidementia drugs (P < .001). Patients with speech therapy or antidepressant drugs received significantly more antidementia drugs (P < .001), whereas patients with physical therapy received significantly fewer antidementia drugs (P = .006)., Conclusion: Antidementia drugs were less likely to be prescribed for patients with poor health status. This result is encouraging for these frail patients who are more vulnerable to the adverse effects of treatments. At the same time, this result encourage targeting specifically patients in good health status for the use of a decision aid, in an attempt to limit prescriptions by involving patients and families., (© 2020 John Wiley & Sons Ltd.)

Introduction: Alzheimer disease (AD) is a neurodegenerative disease characterized by progressive cognitive dysfunction, which is mainly manifested as memory impairment and a reduced ability to self-care, often accompanied by neuropsychiatric and behavioral disorders. Donepezil is the second drug to be approved by the US FDA for the treatment of AD. Of the five FDA-approved drugs for AD treatment, donepezil is currently the most widely used. Here, we report an extrapyramidal adverse reaction to donepezil in an elderly patient with AD., Patient Concerns: An 87-year-old woman presented with a 1-year history of forgetfulness that was aggravated since the past 2 months. She had a long-term history of multiple major conditions, including hypertension, diabetes, osteoporosis, and arterial plaques. Brain imaging showed age-related changes, and her Mini Mental State Examination score was 20. Other tests revealed no abnormalities apart from multiple thyroid nodules on ultrasonography., Diagnosis: She was diagnosed with AD, hypertension, type 2 diabetes mellitus, diabetic neuropathy, osteoporosis, carotid and lower-extremity arterial plaques, thyroid nodules., Interventions: She was treated with donepezil (5 mg/day), amlodipine besylate (5 mg/day), glimepiride (4 mg/day), methylcobalamin (1.5 mg/day), calcium carbonate D3 (600 mg/day), simvastatin (20 mg/day) and enteric-coated aspirin (100 mg/day)., Outcomes: Four days later, she experienced fatigue, panic, sweating, and one episode of vomiting. On the 5th day, she developed increased muscle tension, speech difficulty, and involuntary tremors. Imaging and blood tests revealed no obvious abnormality, and the patient was not receiving psychotropic drugs. An extrapyramidal adverse reaction to donepezil was considered, and the drug was discontinued, after which the symptoms gradually disappeared., Conclusion: Serious adverse reactions to donepezil can occur in elderly patients, who typically require multiple medications for a variety of comorbidities. In particular, extrapyramidal reactions have occurred when donepezil is administered in combination with psychotropic drugs. However, in our patient, an extrapyramidal adverse reaction occurred in the absence of psychotropic drugs. Thus, clinicians must be aware of inter-individual differences in drug actions and possible serious adverse reactions, and carefully monitor these patients to ensure the timely detection of adverse events and their safe treatment.

Background: The anticholinesterase neostigmine and the muscarinic inhibitor glycopyrrolate are frequently coadministered for the reversal of neuromuscular blockade. This practice can precipitate severe bradycardia or tachycardia, but whether it affects the incidence of cardiovascular complications remains unclear. We hypothesized that anticholinesterase reversal with neostigmine and glycopyrrolate versus no anticholinesterase reversal increases the risk of postoperative cardiovascular complications among adult patients undergoing noncardiac surgery with general anesthesia., Methods: We conducted a prespecified retrospective analysis of hospital registry data from a major health care network for patients undergoing surgery with general anesthesia from January 2007 to December 2015. The primary outcome was a composite of cardiac dysrhythmia, acute heart failure, transient ischemic attack, ischemic stroke, and acute myocardial infarction within 30 days after surgery. We performed sensitivity analyses in subgroups and propensity score adjustment and explored the association between exposure and outcome in subgroups of patients with high risk of cardiovascular complications., Results: Of the 98,147 cases receiving neuromuscular blockade, 73,181 (74.6%) received neostigmine and glycopyrrolate, while 24,966 (25.4%) did not. A total of 5612 patients (7.7%) in the anticholinesterase reversal group and 1651 (6.6%) in the control group (P < .001) experienced the primary outcome. After adjustment for clinical covariates, neostigmine and glycopyrrolate exposure was significantly associated in a dose-dependent fashion (P for trend <.001, respectively) with tachycardia (adjusted odds ratio = 2.1 [95% CI, 1.97-2.23]; P < .001) and bradycardia (adjusted odds ratio = 2.84 [95% CI, 2.49-3.24]; P < .001) but not with postoperative cardiovascular complications (adjusted odds ratio = 1.03 [95% CI, 0.97-1.1]; P = .33). We identified a significant effect modification of anticholinesterase reversal by high age, high-risk surgery, and history of atrial fibrillation (P for interaction = .002, .001, and .02, respectively). By using linear combinations of main effect and exposure-risk interaction terms, we detected significant associations between anticholinesterase reversal and cardiovascular complications toward a higher vulnerability in these patient subgroups., Conclusions: Neuromuscular blockade reversal with neostigmine and glycopyrrolate was associated with an increased incidence of intraoperative tachycardia and bradycardia but not with 30-day postoperative cardiovascular complications. Exploratory analyses suggest that a high postoperative cardiovascular complication risk profile may modify the effects of anticholinesterase reversal toward clinical relevance.

Cognitive impairment is a common complication observed after a stroke. Currently there are no definitively proven pharmacologic therapies for recovery from post-stroke cognitive impairment and vascular dementia. In this meta-analysis, we evaluated the efficacy and safety of cholinesterase inhibitors in their improvement of cognition in patients with post-stroke cognitive impairment and vascular dementia. We conducted a meta-analysis using seven eligible studies from 305 published articles. We investigated the differences in Mini-Mental State Examination (MMSE) and Alzheimer's Disease Assessment Scale-Cognitive subscale (ADAS-Cog) scores, before and after cholinergic augmentation in patients with post-stroke cognitive impairment and vascular dementia. MMSE and ADAS-cog scores were also compared during the subsequent follow-up periods. MMSE score of patients with post-stroke cognitive impairment was increased after cholinergic augmentation throughout the 24 weeks with mean differences [MD] of 3.000, 1.732, 1.578 1.516, and 1.222, at 4, 4-8, 8-12, 12-18, and 18-24 weeks, respectively. In addition, ADAS-cog scores decreased at 6, 12, 18, and 24 weeks by pharmaceutical augmentation, but not with placebo with mean differences [MD] of -2.333, -2.913, -2.767, -2.416, and -1.859, respectively. This meta-analysis shows that acetylcholinesterase inhibitors maintain a stable pattern of improved cognitive function in patients with post stroke cognitive impairment and vascular dementia without the increased risk of side effects., Competing Interests: The authors have declared that no competing interests exist.

Nicotinic acetylcholine receptor activation on the perivascular sympathetic nerves via axo-axonal interaction mechanism causes norepinephrine release, which triggers the neurogenic nitrergic relaxation in basilar arteries to meet the need of a brain. Donepezil and huperzine A, which are the cholinesterase inhibitors used for Alzheimer's disease therapy, exert controversial effects on nicotinic acetylcholine receptors. Therefore, we investigated how donepezil and huperzine A via the axo-axonal interaction regulate the neurogenic vasodilation of isolated porcine basilar arteries and define their action on different subtypes of the nicotinic acetylcholine receptor by using blood vessel myography, calcium imaging, and electrophysiological techniques. Both nicotine (100 μM) and transmural nerve stimulation (TNS, 8 Hz) induce NO-mediated dilation in the arteries. Nicotine-induced vasodilations were concentration-dependently inhibited by huperzine A and donepezil, with the former being 30 fold less potent than the latter. Both cholinesterase inhibitors weakly and equally decreased TNS-elicited nitrergic vasodilations. Neither huperzine A nor donepezil affected isoproterenol (a β adrenoceptor-agonist)- or sodium nitroprusside (a NO donor)-induced vasodilation. Further, huperzine A was less potent than donepezil in inhibiting nicotine-elicited calcium influxes in rodent superior cervical ganglionic neurons and inward currents in α7- and α3β2-nicotinic acetylcholine receptor-expressing Xenopus oocytes. In conclusion, huperzine A may exert less harmful effect over donepezil on maintaining brainstem circulation and on the nicotinic acetylcholine receptor-associated cognition deficits during treatment for Alzheimer's disease., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Background: Although cases of anaphylaxis caused by sugammadex have been reported, its incidence remains uncertain. Conversely, no studies have evaluated the incidence of anaphylaxis to neostigmine., Methods: This was a retrospective multicentre observational study of patients who underwent surgery under general anaesthesia between 2012 and 2016 to compare the incidence of anaphylaxis with sugammadex with that of neostigmine at four tertiary hospitals in Japan. To ensure the quality of diagnosis, only cases with a clinical history suggestive of anaphylaxis, along with positive results from in vitro or in vivo testing, were assessed., Results: From a total of 49 532 patients who received general anaesthesia included in this study, 18 cases of anaphylaxis were reported, of which six were attributable to sugammadex and none to neostigmine. There were no fatalities attributable to anaphylaxis. The incidence of anaphylaxis caused by all drugs or by sugammadex was calculated as 0.036% (95% confidence interval [CI]: 0.022-0.057%) and 0.02% (of the number of sugammadex cases) (95% CI: 0.007-0.044%), respectively., Conclusions: The results suggest that neostigmine might be safer than sugammadex when assessing only the incidence of anaphylaxis. We believe that there is room for reconsideration of the choice of reversal agent for neuromuscular blocking agents by all anaesthetists., Clinical Trial Registration: UMIN000022365; UMIN000033561., (Copyright © 2019 The Author(s). Published by Elsevier Ltd.. All rights reserved.)