A 24-week, double-blind, placebo-controlled trial of donepezil in patients with Alzheimer's disease. Donepezil Study Group

Lessons learned from the failure of solanezumab as a prospective treatment strategy for Alzheimer's disease

INTRODUCTION

In the last decade, the efforts conducted for discovering Alzheimer's Disease (AD) treatments targeting the best-known pathogenic factors [amyloid-β (Aβ), tau protein, and neuroinflammation] were mostly unsuccessful. Given that a systemic failure of Aβ clearance was supposed to primarily contribute to AD development and progression, disease-modifying therapies with anti-Aβ monoclonal antibodies (e.g. solanezumab, bapineuzumab, gantenerumab, aducanumab, lecanemab and donanemab) are ongoing in randomized clinical trials (RCTs) with contrasting results.

AREAS COVERED

The present Drug Discovery Case History analyzes the failures of RCTs of solanezumab on AD. Furthermore, the authors review the pharmacokinetics, pharmacodynamics, and tolerability effect of solanezumab from preclinical studies with its analogous m266 in mice. Finally, they describe the RCTs with cognitive, cerebrospinal fluid and neuroimaging findings in mild-to-moderate AD (EXPEDITION studies) and in secondary prevention studies (A4 and DIAN-TU).

EXPERT OPINION

Solanezumab was one of the first anti-Aβ monoclonal antibodies to be tested in preclinical and clinical AD showing to reduce brain Aβ level by acting on soluble monomeric form of Aβ peptide without significant results on deposits. Unfortunately, this compound showed to accelerate cognitive decline in both asymptomatic and symptomatic trial participants, and this failure of solanezumab further questioned the Aβ cascade hypothesis of AD.

Evaluating the efficacy and safety of Alzheimer's disease drugs: A meta-analysis and systematic review

BACKGROUND

Alzheimer's disease (AD) is a progressive neurodegenerative disorder. Dementia severity was assessed mainly through cognitive function, psychobehavioral symptoms, and daily living ability. Currently, there are not many drugs that can be selected to treat mild to moderate AD, and the value of drugs remains controversial.

OBJECTIVE

The aim of this study is to quantitatively evaluate the efficacy and safety of cholinesterase inhibitors (ChEIs), memantine, and sodium oligomannate (GV-971) in the treatment of patients with AD. Additionally, molecular docking analysis will be used to investigate the binding affinities of donepezil, galantamine, rivastigmine, and memantine with key receptor proteins associated with AD, including beta-amyloid (Abeta), microtubule-associated protein (MAP), apolipoprotein E4 (APOE4), and Mitofusin-2 (MFN2), to further validate the results of the meta-analysis.

METHODS

We obtained clinical trials characterized by randomization, placebo control, and double-blinded methodologies concerning ChEIs, memantine, and GV-971. Statistical analysis was performed using Review Manager Version 5.4 software. Molecular docking was also conducted to evaluate the results.

RESULTS

All drugs improved the cognitive function, with the effect value ranging from -1.23 (95% CI -2.17 to -0.30) for 20 mg memantine to -3.29 (95% CI -4.14 to -2.45) for 32 mg galantamine. Although 32 mg galanthamine and GV-971 did not improve the clinicians' Global Impression of Change scale, other drugs showed significant results compared with placebo. On NPI, only 10 mg of donepezil and 24 mg of galantamine had improvement effects. On ADCS/ADL, only 20 mg memantine and 900 mg GV-971 had no significant difference from the placebo. Donepezil 5 mg and GV-971 900 mg did not increase the drug withdrawal rates due to various reasons or adverse reactions when compared to the placebo. Donepezil demonstrated superior binding to the protein and exhibited greater efficacy compared to other drugs.

CONCLUSION

ChEIs, memantine, and GV-971 all can slow the progression of AD but have different effects on respective assessments. Donepezil and GV-971 were relatively well tolerated.

Lecanemab Questions

The recently published results of the 18-month randomized controlled trial of lecanemab, reporting the efficacy of the drug in slowing the progression of early Alzheimer disease, quickly led to approval by the FDA and widespread acceptance of lecanemab treatment. However, there are a number of matters that deserve further consideration. The success of blinding was not assessed, even as infusion reactions and the cerebral pathology underlying amyloid-related imaging abnormalities could have signaled to many participants that they were on drug, potentially exerting a potent placebo effect. The value of the outcome to participants is not defined in the absolute terms necessary for clinical decision-making, and the difference attributable to lecanemab was between 18% and 46% of estimates of the minimal clinically important difference on the Clinical Dementia Rating Scale Sum of Boxes. The attenuation of change on the Alzheimer's Disease Assessment Scale-Cognitive 14 achieved by lecanemab at 18 months was 50% of that achieved by donepezil at 6 months. Lecanemab treatment imposes a high treatment burden. The fact that the burden commences at the initiation of lecanemab treatment, whereas the benefit accrues years later requires us to take into account value discounting over time, which would significantly reduce the benefit/burden ratio. Finally, treatment with monoclonal antibodies to cerebral amyloid has consistently been associated with progressive cerebral atrophy. At the least, these issues should be raised in treatment discussions with patients. They also suggest a need to very seriously reconsider how we evaluate clinical trial results preparatory to translating them into clinical practice. Some suggestions are provided.

Donepezil-induced bradycardia in a schizophrenic patient with comorbid neurocognitive disorder: a case report and review of the literature

BACKGROUND

Trials of cholinergic and glutamatergic agents have improved cognition and memory for the geriatric schizophrenic population. Donepezil is an acetylcholinesterase inhibitor that improves cognition by preventing postsynaptic degradation of hippocampal acetylcholine in patients with mild-to-moderate dementia. Donepezil has been attributed to some adverse effects, especially gastrointestinal symptoms. However, cardiovascular adverse effects are not common as there remains a dearth of literature regarding donepezil-induced bradycardia.

CASE REPORT

Hence, we present the case of a 70-year-old Hispanic female with past psychiatry history of schizophrenia who developed bradycardia and syncope following the commencement of low-dose donepezil in the inpatient unit and subsequent resolution with cessation. She had no prior cardiovascular symptoms or diagnosis.

DISCUSSION

Considering there is no baseline cardiac monitoring requirement guideline for patients on Donepezil treatment, pre-assessment electrocardiogram is advised before the commencement of acetylcholinesterase inhibitors. Finally, routine monitoring of vital signs for at least the first 72 hours following the start of donepezil might be good proactive practice for all psychiatrists. Extending this practice to inpatient and outpatient service settings will be worthwhile.

Bioactive cholinesterase inhibitions of clerodanes from the flowers of Croton krabas and molecular docking studies

The first investigation of the phytochemical profile of the flowers of Croton krabas led to the isolation of two new clerodane diterpenes, 6S-crotocaudin (1) and crotocaudin B (2), together with two known clerodanes, 6S-crotoeurin C (3) and isoteucvin (4). The structures and absolute configurations of isolated clerodanes were elucidated by extensive analysis of NMR spectroscopic data, mass spectrometry and ECD calculations. Compounds 1-4 demonstrated significant inhibitory activity towards acetylcholinesterase (AChE). Notably, compound 2 exhibited the strongest AChE inhibition (IC50 1.01 µM). Compounds 3 and 4 showed potent butyrylcholinesterase (BChE) inhibitory activity with IC50 values of 1.09 and 1.12 µM, respectively. The molecular docking results revealed that 2 bound to the catalytic anionic site (CAS) and peripheral anionic site (PAS) of AChE, while 3 occupied in the CAS of BChE.

Mechanisms with network pharmacology approach of Ginsenosides in Alzheimer's disease

Alzheimer's disease (AD) is a progressive neurodegenerative disease characterized by memory loss, cognitive disorder, language dysfunction, and mental disability. The main neuropathological changes in AD mainly include amyloid plaque deposition, neurofibrillary tangles, synapse loss, and neuron reduction. However, the current anti-AD drugs do not demonstrate a favorable effect in altering the pathological course of AD. Moreover, long-term use of these drugs is usually accompanied with various side effects. Ginsenosides are the major active constituents of ginseng and have protective effects on AD through various mechanisms in both in vivo and in vitro studies. In this review, we focused on discussing the therapeutic potential effects and the mechanisms of pharmacological activities of ginsenosides in AD, to provide new insight for further research and clinical application of ginsenosides in the future. Recent studies on the pharmacological effects and mechanisms of ginsenosides were retrieved from Chinese National Knowledge Infrastructure, National Science and Technology Library, Wanfang Data, Elsevier, ScienceDirect, PubMed, SpringerLink, and the Web of Science database up to April 2023 using relevant keywords. Network pharmacology and bioinformatics analysis were used to predict the therapeutic effects and mechanisms of ginsenosides against AD. Ginsenosides presented a wide range of therapeutic and biological activities, including alleviating Aβ deposition, decreasing tau hyperphosphorylation, regulating the cholinergic system, resisting oxidative stress, modulating Ca2+ homeostasis, as well as anti-inflammation and anti-apoptosis in neurons, respectively. For further developing the therapeutic potential as well as clinical applications, the network pharmacology approach was combined with a summary of published studies.

Shortening the Alzheimer's disease assessment scale cognitive subscale

BACKGROUND

A short yet reliable cognitive measure is needed that separates treatment and placebo for treatment trials for Alzheimer's disease. Hence, we aimed to shorten the Alzheimer's Disease Assessment Scale Cognitive Subscale (ADAS-Cog) and test its use as an efficacy measure.

METHODS

Secondary data analysis of participant-level data from five pivotal clinical trials of donepezil compared with placebo for Alzheimer's disease (N = 2,198). Across all five trials, cognition was appraised using the original 11-item ADAS-Cog. Statistical analysis consisted of sample characterization, item response theory (IRT) to identify an ADAS-Cog short version, and mixed models for repeated-measures analysis to examine the effect sizes of ADAS-Cog change on the original and short versions in the placebo versus donepezil groups.

RESULTS

Based on IRT, a short ADAS-Cog was developed with seven items and two response options. The original and short ADAS-Cog correlated at baseline and at weeks 12 and 24 at 0.7. Effect sizes based on mixed modeling showed that the short and original ADAS-Cog separated placebo and donepezil comparably (ADAS-Cog original ES = 0.33, 95% CI = 0.29, 0.40, ADAS-Cog short ES = 0.25, 95% CI =0.23, 0.34).

CONCLUSIONS

IRT identified a short ADAS-cog version that separated donepezil and placebo, suggesting its clinical potential for assessment and treatment monitoring.

Clinical importance in Alzheimer's disease: effects of anchor agreement and disease severity

OBJECTIVES

Methods of evaluating clinically meaningful decline are critical in research on Alzheimer's disease. A common method of quantifying clinically meaningful change is to calculate an anchor-based minimal clinically important difference (MCID) score. In this approach, individuals who report a meaningful change serve as the "anchors", and the mean level of change for this group serves as the MCID. In research on Alzheimer's disease, there are several possible anchors, including patients, knowledgeable observers (e.g., a family member), and clinicians. The goal of this study was to examine the extent to which agreement among anchors impacts MCID estimation and whether this relationship is moderated by cognitive severity status.

METHODS

Analyses were completed on a longitudinal sample of 2247 adults, aged 50-103, from the Uniform Data Set. Outcome measures included the Montreal Cognitive Assessment, Clinical Dementia Rating-Sum of Boxes, and Functional Activities Questionnaire.

RESULTS

For all of the outcomes, the MCID estimate was significantly higher when meaningful decline was endorsed by all of the anchors compared to when there was disagreement among the anchors. In addition, the MCID estimate was higher with increasing severity of cognitive impairment. Finally, cognitive severity status moderated the influence of agreement among anchors on MCID estimation; as disease severity increased, anchor agreement demonstrated less influence on the MCID.

CONCLUSIONS

MCID estimates based on one anchor may underestimate meaningful change, and researchers should consider the viewpoints of multiple anchors in constructing MCIDs, particularly in the early stages of cognitive decline.

Epigallocatechin-3-Gallate and Genistein for Decreasing Gut Dysbiosis, Inhibiting Inflammasomes, and Aiding Autophagy in Alzheimer's Disease

There are approximately 24 million cases of Alzheimer's disease (AD) worldwide, and the number of cases is expected to increase four-fold by 2050. AD is a neurodegenerative disease that leads to severe dementia in most patients. There are several neuropathological signs of AD, such as deposition of amyloid beta (Aβ) plaques, formation of neurofibrillary tangles (NFTs), neuronal loss, activation of inflammasomes, and declining autophagy. Several of these hallmarks are linked to the gut microbiome. The gastrointestinal (GI) tract contains microbial diversity, which is important in regulating several functions in the brain via the gut-brain axis (GBA). The disruption of the balance in the gut microbiota is known as gut dysbiosis. Recent studies strongly support that targeting gut dysbiosis with selective bioflavonoids is a highly plausible solution to attenuate activation of inflammasomes (contributing to neuroinflammation) and resume autophagy (a cellular mechanism for lysosomal degradation of the damaged components and recycling of building blocks) to stop AD pathogenesis. This review is focused on two bioflavonoids, specifically epigallocatechin-3-gallate (EGCG) and genistein (GS), as a possible new paradigm of treatment for maintaining healthy gut microbiota in AD due to their implications in modulating crucial AD signaling pathways. The combination of EGCG and GS has a higher potential than either agent alone to attenuate the signaling pathways implicated in AD pathogenesis. The effects of EGCG and GS on altering gut microbiota and GBA were also explored, along with conclusions from various delivery methods to increase the bioavailability of these bioflavonoids in the body.

Cholinesterase inhibitors and falls, syncope and injuries in patients with cognitive impairment: a systematic review and meta-analysis

BACKGROUND

Cholinesterase inhibitors are commonly used to treat patients with neurocognitive disorders, who often have an elevated risk of falling. Effective use of these medications requires a thoughtful assessment of risks and benefits.

OBJECTIVE

To provide an update on previous reviews and determine the association between cholinesterase inhibitors and falls, syncope, fracture and accidental injuries in patients with neurocognitive disorders.

METHODS

Embase, MEDLINE, Cochrane Central Register of Controlled Trials, Cumulative Index of Nursing and Allied Health Literature and AgeLine were systematically searched through March 2023 to identify all randomised controlled trials of cholinesterase inhibitors (donepezil, galantamine, rivastigmine) in patients with cognitive impairment. Corresponding authors were contacted for additional data necessary for meta-analysis. Inclusion criteria consisted of adults ≥19 years, with a diagnosis of dementia, Parkinson's disease, mild cognitive impairment or traumatic brain injury. Data were extracted in duplicate for the aforementioned primary outcomes and all outcomes were analysed using random-effects meta-analysis.

RESULTS

Fifty three studies (30 donepezil, 14 galantamine, 9 rivastigmine) were included providing data on 25, 399 patients. Cholinesterase inhibitors, compared to placebo, were associated with reduced risk of falls (risk ratio [RR] 0.84 [95% confidence interval [CI] = 0.73-0.96, P = 0.009]) and increased risk of syncope (RR 1.50 [95% CI = 1.02-2.21, P = 0.04]). There was no association with accidental injuries or fractures.

CONCLUSION

In patients with neurocognitive disorders, cholinesterase inhibitors were associated with decreased risk of falls, increased risk of syncope and no association with accidental trauma or fractures. These findings will help clinicians better evaluate risks and benefits of cholinesterase inhibitors.

Potentially inappropriate medication and frailty in older adults: A systematic review and meta-analysis

OBJECTIVES

The purpose of this study was to systematically assess existing studies to demonstrate the association between potentially inappropriate medication (PIM) and frailty.

DESIGN

Systematic review and meta-analysis.

METHODS

We searched major electronic databases (PubMed, Web of Science, the Cochrane Library, Embase, CINHAL, PsycInfo, China National Knowledge Infrastructure, China Biology Medicine disk, Weipu, and Wanfang) from their inception until February 25, 2023 (data updated on May 4, 2023), for observational studies investigating PIM and frailty. I2 was used to measure the heterogeneity between studies quantitatively. A random effect model calculated pooled effect size owing to high heterogeneity. Subgroup analysis was conducted to explore sources of heterogeneity. Additionally, the studies' quality was evaluated using the Newcastle Ottawa Scale (a modified Newcastle Ottawa Scale was used to evaluate cross-sectional studies).

RESULTS

Twenty-four studies were included for systematic review, 14 of which were included in the meta-analysis. After pooling the effect size, the odds ratio with PIM as the dependent variable was 1.12 (95%CI: 1.01-1.25), and that with frailty as the dependent variable was 1.75 (95%CI: 1.25-2.43), indicating a bidirectional association between PIM and frailty.

CONCLUSIONS

PIM and frailty interact with each other and have a bidirectional association, thus providing additional information for early clinical identification and prevention of frailty, and medication safety management.

A Randomized Double-blind Study to Assess the Skin Irritation and Sensitization Potential of a Once-weekly Donepezil Transdermal Delivery System in Healthy Volunteers

BACKGROUND

A once-weekly donepezil transdermal delivery system (TDS; Adlarity; Corium, LLC) is indicated for the treatment of mild, moderate, and severe dementia of the Alzheimer type.

METHODS

In this placebo-controlled, randomized, double-blind phase 1 trial, healthy volunteers aged 40 years or older were randomized to receive a placebo and donepezil TDS and were evaluated for the primary endpoints of skin irritation and sensitization potential. Skin irritation was scored.

RESULTS

Two hundred fifty-six participants were randomized and received ≥1 dose of any treatment. After the first weekly TDS application, no skin irritation or minimal irritation was evident between donepezil and placebo TDSs. At the third weekly TDS application, for donepezil TDS, the average of the mean combined skin irritation score was 0.55 of a possible maximum of 7, indicating none to minimal skin irritation, and for placebo, the score was 0.19, indicating no skin irritation. Of 198 participants, 4 (2.0%) were considered potentially sensitized to donepezil TDS, and 0 were potentially sensitized to placebo TDS.

CONCLUSION

Once-weekly 5-mg/d donepezil TDS demonstrated minimal skin irritation under conditions of use of 3 consecutive weekly patch applications to the same skin site and minimal sensitization potential.

American Ginseng for the Treatment of Alzheimer's Disease: A Review

Alzheimer's disease (AD) is a prevalent degenerative condition that is increasingly affecting populations globally. American ginseng (AG) has anti-AD bioactivity, and ginsenosides, as the main active components of AG, have shown strong anti-AD effects in both in vitro and in vivo studies. It has been reported that ginsenosides can inhibit amyloid β-protein (Aβ) production and deposition, tau phosphorylation, apoptosis and cytotoxicity, as well as possess anti-oxidant and anti-inflammatory properties, thus suppressing the progression of AD. In this review, we aim to provide a comprehensive overview of the pathogenesis of AD, the potential anti-AD effects of ginsenosides found in AG, and the underlying molecular mechanisms associated with these effects. Additionally, we will discuss the potential use of AG in the treatment of AD, and how ginsenosides in AG may exert more potent anti-AD effects in vivo may be a direction for further research.

Turning the Spotlight to Cholinergic Pharmacotherapy of the Human Language System

Even though language is essential in human communication, research on pharmacological therapies for language deficits in highly prevalent neurodegenerative and vascular brain diseases has received little attention. Emerging scientific evidence suggests that disruption of the cholinergic system may play an essential role in language deficits associated with Alzheimer's disease and vascular cognitive impairment, including post-stroke aphasia. Therefore, current models of cognitive processing are beginning to appraise the implications of the brain modulator acetylcholine in human language functions. Future work should be directed further to analyze the interplay between the cholinergic system and language, focusing on identifying brain regions receiving cholinergic innervation susceptible to modulation with pharmacotherapy to improve affected language domains. The evaluation of language deficits in pharmacological cholinergic trials for Alzheimer's disease and vascular cognitive impairment has thus far been limited to coarse-grained methods. More precise, fine-grained language testing is needed to refine patient selection for pharmacotherapy to detect subtle deficits in the initial phases of cognitive decline. Additionally, noninvasive biomarkers can help identify cholinergic depletion. However, despite the investigation of cholinergic treatment for language deficits in Alzheimer's disease and vascular cognitive impairment, data on its effectiveness are insufficient and controversial. In the case of post-stroke aphasia, cholinergic agents are showing promise, particularly when combined with speech-language therapy to promote trained-dependent neural plasticity. Future research should explore the potential benefits of cholinergic pharmacotherapy in language deficits and investigate optimal strategies for combining these agents with other therapeutic approaches.

Efficacy and Safety of a Transdermal Donepezil Patch in Patients with Mild to Moderate Alzheimer's Disease: Open-Label, Extension Study

BACKGROUND

In Japan, only oral formulation of donepezil hydrochloride is approved for the treatment of Alzheimer's disease.

OBJECTIVE

To evaluate safety and efficacy of a donepezil patch 27.5 mg application for 52 weeks in patients with mild-to-moderate Alzheimer's disease; and to evaluate safety on switching from donepezil hydrochloride tablets.

METHODS

This 28-week, open-label study (jRCT2080224517) is an extension of a 24-week double-blind (donepezil patch 27.5 mg versus donepezil hydrochloride tablet 5 mg) noninferiority study. The patch group (continuation group) continued administration of the patch and the tablet group (switch group) switched to the patch in this study.

RESULTS

A total of 301 patients participated (156 patients continued using patches; 145 patients switched). Both groups showed similar course on the Alzheimer's Disease Assessment Scale-cognitive component-Japanese version (ADAS-Jcog) and ABC dementia scales. At weeks 36 and 52, changes in ADAS-Jcog from week 24 [mean (standard deviation)] were 1.4 (4.8) and 2.1 (4.9) in the continuation group, and 1.0 (4.2), and 1.6 (5.4) in the switch group. The incidence of adverse events at application site in the continuation group over 52 weeks was 56.6% (98/173). Erythema, pruritus, and contact dermatitis at application site were observed in more than 10 patients each. There was no additional adverse event of clinical concern, and no increase in their incidence from the double-blind study. During the four weeks following switching, no patient discontinued or suspended administration due to adverse events.

CONCLUSION

Application of the patch for 52 weeks was well tolerated and feasible, including switching from tablets.

Improving Visual Working Memory with Cholinergic Deep Brain Stimulation

Acetylcholine is a critical modulatory neurotransmitter for cognitive function. Cholinergic drugs improve cognitive performance and enhance neuronal activity in the sensory and association cortices. An alternative means of improving cognitive function is through the use of deep brain stimulation. Prior animal studies have demonstrated that stimulation of the nucleus basalis of Meynert through DBS improves cognitive performance on a visual working memory task to the same degree as cholinesterase inhibitors. Additionally, unlike current pharmacological treatments for neurocognitive disorders, DBS does not lose efficacy over time and adverse effects are rare. These findings suggest that DBS may be a promising alternative for treating cognitive impairments in neurodegenerative disorders such as Alzheimer's disease. Thus, further research and human trials should be considered to assess the potential of DBS as a therapeutic treatment for these disorders.

Effects of Donepezil on the Musculoskeletal System in Female Rats

The extension of human life makes it more and more important to prevent and treat diseases of the elderly, including Alzheimer's disease (AD) and osteoporosis. Little is known about the effects of drugs used in the treatment of AD on the musculoskeletal system. The aim of the present study was to investigate the effects of donepezil, an acetylcholinesterase inhibitor, on the musculoskeletal system in rats with normal and reduced estrogen levels. The study was carried out on four groups of mature female rats: non-ovariectomized (NOVX) control rats, NOVX rats treated with donepezil, ovariectomized (OVX) control rats and OVX rats treated with donepezil. Donepezil (1 mg/kg p.o.) was administered for four weeks, starting one week after the ovariectomy. The serum concentrations of CTX-I, osteocalcin and other biochemical parameters, bone mass, density, mineralization, histomorphometric parameters and mechanical properties, and skeletal muscle mass and strength were examined. Estrogen deficiency increased bone resorption and formation and worsened cancellous bone mechanical properties and histomorphometric parameters. In NOVX rats, donepezil decreased bone volume to tissue volume ratio in the distal femoral metaphysis, increased the serum phosphorus concentration and tended to decrease skeletal muscle strength. No significant bone effects of donepezil were observed in OVX rats. The results of the present study indicate slightly unfavorable effects of donepezil on the musculoskeletal system in rats with normal estrogen levels.

Analysis of Adverse Events of Cholinesterase Inhibitors and NMDA Receptor Antagonists on Arrhythmias Using the Japanese Adverse Drug Event Report Database

BACKGROUND

The association between anti-dementia drugs and arrhythmia is uncertain. In addition, the effects of certain drug combinations are not yet well known.

OBJECTIVE

We investigated the association between anti-dementia drugs and arrhythmia. Furthermore, we investigated the effects of anti-dementia drugs both alone and in combination on the likelihood of arrhythmia in patients with dementia.

METHODS

We examined the Japanese Adverse Drug Event Report database (JADER) from April 2004 to May 2022 for dementia drug users aged ≥ 60 years. We calculated the unadjusted reported odds ratio (ROR) and adjusted ROR for confounding factors. Furthermore, we examined the association of various combinations of anti-dementia drugs with the development of arrhythmias.

RESULTS

There were 6718 arrhythmia cases identified out of 333,702 reported cases. The unadjusted ROR results were as follows: donepezil alone (ROR 4.39, 95% confidence interval [CI] 3.89-4.95), rivastigmine alone (2.10, 1.53-2.87), galantamine alone (3.87, 3.04-4.94), memantine alone (2.25, 1.59-3.20), and combination of choline esterase inhibitor and memantine (2.56, 1.84-3.57). In a multivariate analysis, the RORs remained significant.

CONCLUSIONS

Regardless of whether anti-dementia drugs were used alone or in combination, attention should be paid to the occurrence of arrhythmias.

Efficacy and safety of a transdermal donepezil patch in patients with mild-to-moderate Alzheimer's disease: A 24-week, randomized, multicenter, double-blind, parallel group, non-inferiority study

AIM

To assess non-inferiority of a donepezil patch 27.5 mg compared with donepezil hydrochloride tablets 5 mg in patients with mild-to-moderate Alzheimer's disease; and to compare the efficacy and safety profiles of a donepezil patch 27.5 mg with donepezil hydrochloride tablets 5 mg.

METHODS

This was a 24-week, multicenter, randomized, double-blind, double-dummy, parallel group, non-inferiority (phase III) study carried out in Japan. The primary end-point was the change in the Alzheimer's Disease Assessment Scale-cognitive component-Japanese version from baseline to week 24, with the aim of evaluating the non-inferiority of the donepezil patch 27.5 mg compared with donepezil hydrochloride tablets 5 mg.

RESULTS

Of 340 randomized patients, 303 completed the double-blind period. Changes from baseline in the Alzheimer's Disease Assessment Scale-cognitive component-Japanese version at week 24 (least squares mean ± standard error) were -0.7 ± 0.4 (donepezil patch 27.5 mg) and 0.2 ± 0.4 (donepezil hydrochloride tablet 5 mg). The difference in the least squares means (95% confidence interval) was -0.9 (-2.01 to 0.14). The upper bound of the 95% confidence interval for the difference between groups was less than the predefined non-inferiority margin of 2.15. The donepezil patches 27.5 mg also had a safety profile that showed good tolerability comparable with donepezil hydrochloride tablets 5 mg.

CONCLUSIONS

Non-inferiority on suppression of cognitive decline was shown for the donepezil patch 27.5 mg when compared with donepezil hydrochloride tablets 5 mg in Japanese patients with mild-to-moderate Alzheimer's disease. Geriatr Gerontol Int 2023; 23: 275-281.

M1/M4-Preferring Muscarinic Cholinergic Receptor Agonist Xanomeline Reverses Wake and Arousal Deficits in Nonpathologically Aged Mice

Degeneration of the cholinergic basal forebrain is implicated in the development of cognitive deficits and sleep/wake architecture disturbances in mild cognitive impairment (MCI) and Alzheimer's disease (AD). Indirect-acting muscarinic cholinergic receptor agonists, such as acetylcholinesterase inhibitors (AChEIs), remain the only FDA-approved treatments for the cognitive impairments observed in AD that target the cholinergic system. Novel direct-acting muscarinic cholinergic receptor agonists also improve cognitive performance in young and aged preclinical species and are currently under clinical development for AD. However, little is known about the effects of direct-acting muscarinic cholinergic receptor agonists on disruptions of sleep/wake architecture and arousal observed in nonpathologically aged rodents, nonhuman primates, and clinical populations. The purpose of the present study was to provide the first assessment of the effects of the direct-acting M1/M4-preferring muscarinic cholinergic receptor agonist xanomeline on sleep/wake architecture and arousal in young and nonpathologically aged mice, in comparison with the AChEI donepezil, when dosed in either the active or inactive phase of the circadian cycle. Xanomeline produced a robust reversal of both wake fragmentation and disruptions in arousal when dosed in the active phase of nonpathologically aged mice. In contrast, donepezil had no effect on either age-related wake fragmentation or arousal deficits when dosed during the active phase. When dosed in the inactive phase, both xanomeline and donepezil produced increases in wake and arousal and decreases in nonrapid eye movement sleep quality and quantity in nonpathologically aged mice. Collectively, these novel findings suggest that direct-acting muscarinic cholinergic agonists such as xanomeline may provide enhanced wakefulness and arousal in nonpathological aging, MCI, and AD patient populations.

Long-Term Safety, Tolerability, and Efficacy of a Transdermal Donepezil Patch in Patients with Severe Alzheimer's Disease

BACKGROUND

Oral formulations are not suitable for demented patients with dysphagia, those refuse to take tablets, or those with drug compliance problem. However, only oral formulations of donepezil hydrochloride are approved for the treatment of severe Alzheimer's disease in Japan.

OBJECTIVE

To evaluate the safety, tolerability, and efficacy of long-term application of a 55.0 mg transdermal donepezil patch switched from a 10 mg oral donepezil hydrochloride tablet, for the treatment of patients with severe Alzheimer's disease.

METHODS

A 52-week, multicenter, open-label, uncontrolled (phase III) study (jRCT2080224612) was conducted in Japan between April 2019 and August 2021. A 10 mg donepezil hydrochloride tablet was administered once a day for four weeks; a 55.0 mg donepezil patch was then applied once a day for 52 weeks in patients with severe Alzheimer's disease.

RESULTS

Of 64 patients received the patch, 45 completed the 52-week period. The overall discontinuation rate was 29.7% (19/64). Among the 19 patients discontinued, six patients 9.4% (6/64) discontinued due to adverse events. The incidence of adverse events at application sites was 67.2% (43/64), including application site erythema 29.7% (19/64), application site pruritus 25.0% (16/64), and contact dermatitis 20.3% (13/64). Adverse events were mild and did not increase with time, demonstrating a favorable safety profile. Cognitive function, measured using the Mini-Mental State Examination, was maintained for up to 24 weeks.

CONCLUSIONS

Adverse events were considered manageable in a clinical setting. The long-term application of a 55.0 mg donepezil patch once a day was feasible treatment in patients with severe Alzheimer's disease.

Exogenous Oxytocin Administration Restores Memory in Female APP/PS1 Mice

BACKGROUND

Current treatment options for Alzheimer's disease (AD) are limited, inefficient, and often have serious side effects. Oxytocin is a neuropeptide implicated in a variety of central processes, such as social and reproductive behaviors. Among others, it has garnered attention in various domains of psychiatric research, while its role in the development and course of neurodegenerative disorders like AD is rather unknown.

OBJECTIVE

This study aimed to investigate the role of exogenous oxytocin administration on memory, specifically in view of AD, as a potential novel treatment option.

METHODS

We describe a novel treatment approach by using a relatively low dose of long-term intranasal oxytocin treatment, to restore memory deficits in female APPswePS1dE9 mice.

RESULTS

Female APPswePS1dE9 mice treated with oxytocin showed increased spatial memory performance in the object location task and improved working memory in the Y-Maze, while indicating decreased sociability.

CONCLUSIONS

These results indicate that oxytocin is able to reverse acquired cognitive deficits in female APPswePS1dE9 mice.

Efficacy of acupuncture in patients with mild Alzheimer's disease and its impact on gut microbiota: Study protocol for a randomized sham-controlled trial

Introduction

Acupuncture is used as an adjuvant therapy for Alzheimer's disease (AD), but available evidence for efficacy is limited so far. Growing studies suggest that resident gut microbiota contributes to the development and progression of AD. Meanwhile, acupuncture is reported to treat gastrointestinal and neurodegenerative disorders via the gut-brain axis. Therefore, our aim is to confirm the adjunctive therapeutic effects of acupuncture for AD, and explore the relationship between clinical efficacy and shifts of gut microbiota.

Methods and analysis

This is a randomized, participant-masked, sham-controlled trial. One hundred and sixty participants with mild AD will be randomly assigned (1:1) to either active acupuncture or non-penetrating sham acupuncture (three times weekly for 14 weeks) added to donepezil treatment (5 mg per day for 28 weeks). The primary efficacy outcome is the change from baseline to week 28 in the Alzheimer's disease Assessment Scale (ADAS-cog12). Secondary efficacy outcomes include other assessments of the Mini-Mental State Examination (MMSE), the Alzheimer's disease Cooperative Study-Activities of Daily Living (ADCS-ADL), and Neuropsychiatric Inventory (NPI). Gut microbiota will be measured using 16S rRNA tag sequencing.

Discussion

This rigorous trial will provide high-quality evidence on the efficacy of acupuncture as adjunctive treatment for mild AD, and identify the possible mechanisms of acupuncture from gut microbiota.

Clinical Trial Registration

[https://clinicaltrials.gov/ct2/show/NCT05078944], ClinicalTrials.gov [NCT05078944]. Registered 15 October 2021.

Anti-Dementia Drug Persistence Following Donepezil Initiation Among Alzheimer's Disease Patients in Japan: LIFE Study

BACKGROUND

Donepezil is frequently used to treat Alzheimer's disease (AD) symptoms but is associated with early discontinuation. Determining the persistence rates of anti-dementia drug use after donepezil initiation may inform the development and improvement of treatment strategies, but there is little evidence from Japan.

OBJECTIVE

To determine anti-dementia drug persistence following donepezil initiation among AD patients in Japan using insurance claims data.

METHODS

Insurance claims data for AD patients with newly prescribed donepezil were obtained from 17 municipalities between April 2014 and October 2021. Anti-dementia drug persistence was defined as a gap of ≤60 days between the last donepezil prescription and a subsequent prescription of donepezil, another cholinesterase inhibitor, or memantine. Cox proportional hazards models were used to analyze the association between care needs levels and discontinuation.

RESULTS

We analyzed 20,474 AD patients (mean age±standard deviation: 82.2±6.3 years, women: 65.7%). The persistence rates were 89.1% at 30 days, 79.4% at 90 days, 72.6% at 180 days, 64.5% at 360 days, and 58.3% at 540 days after initiation. Among the care needs levels, the hazard ratio (95% confidence interval) for discontinuation was 1.01 (0.94-1.07) for patients with support needs, 1.12 (1.06-1.18) for patients with low long-term care needs, and 1.31 (1.21-1.40) for patients with moderate-to-high long-term care needs relative to independent patients.

CONCLUSION

Japanese AD patients demonstrated low anti-dementia drug persistence rates that were similar to those of other countries. Higher long-term care needs were associated with discontinuation. Further measures are needed to improve drug persistence in AD patients.

Metallothionein synthesis increased by Ninjin-yoei-to, a Kampo medicine protects neuronal death and memory loss after exposure to amyloid β1-42

BACKGROUND

It is possible that increased synthesis of metallothioneins (MTs), Zn²⁺-binding proteins is linked with the protective effect of Ninjin-yoei-to (NYT) on Zn²⁺ toxicity ferried by amyloid β_1-42 (Aβ_1-42).

METHODS

Judging from the biological half-life (18-20 h) of MTs, the effective period of newly synthesized MT on capturing Zn²⁺ is estimated to be approximately 2 days. In the present paper, a diet containing 3% NYT was administered to mice for 2 days and then Aβ_1-42 was injected into the lateral ventricle of mice.

RESULTS

MT level in the dentate granule cell layer was elevated 2 days after administration of NYT diet, while the administration reduced intracellular Zn²⁺ level increased 1 h after Aβ_1-42 injection, resulting in rescuing neuronal death in the dentate granule cell layer, which was observed 14 days after Aβ_1-42 injection. Furthermore, Pre-administration of NYT diet rescued object recognition memory loss via affected perforant pathway long-term potentiation after local injection of Aβ_1-42 into the dentate granule cell layer of rats.

CONCLUSION

The present study indicates that pre-administration of NYT diet for 2 days increases synthesis of MTs, which reduces intracellular Zn²⁺ toxicity ferried by extracellular Aβ_1-42, resulting in protecting neuronal death in the dentate gyrus and memory loss after exposure to Aβ_1-42.

The Dose and Duration-dependent Association between Melatonin Treatment and Overall Cognition in Alzheimer's Dementia: A Network Meta- Analysis of Randomized Placebo-Controlled Trials

BACKGROUND

While Alzheimer's dementia (AD) has a prevalence as high as 3-32% and is associated with cognitive dysfunction and the risk of institutionalization, no efficacious and acceptable treatments can modify the course of cognitive decline in AD. Potential benefits of exogenous melatonin for cognition have been divergent across trials.

OBJECTIVE

The current network meta-analysis (NMA) was conducted under the frequentist model to evaluate the potential beneficial effects of exogenous melatonin supplementation on overall cognitive function in participants with AD in comparison to other FDA-approved medications (donepezil, galantamine, rivastigmine, memantine, and Namzaric).

METHODS

The primary outcome was the changes in the cognitive function [measured by mini-mental state examination (MMSE)] after treatment in patients with Alzheimer's dementia. The secondary outcomes were changes in the quality of life, behavioral disturbance, and acceptability (i.e., drop-out due to any reason and rate of any adverse event reported).

RESULTS

The current NMA of 50 randomized placebo-controlled trials (RCTs) revealed the medium-term lowdose melatonin to be associated with the highest post-treatment MMSE (mean difference = 1.48 in MMSE score, 95% confidence intervals [95% CIs] = 0.51 to 2.46) and quality of life (standardized mean difference = -0.64, 95% CIs = -1.13 to -0.15) among all of the investigated medications in the participants with AD. Finally, all of the investigated exogenous melatonin supplements were associated with similar acceptability as was the placebo.

CONCLUSION

The current NMA provides evidence for the potential benefits of exogenous melatonin supplementation, especially medium-term low-dose melatonin, in participants with AD.

Personalized Prediction of Alzheimer’s Disease and Its Treatment Effects by Donepezil: An Individual Participant Data Meta-Analysis of Eight Randomized Controlled Trials

Background: Patient characteristics may predict the progression of Alzheimer’s disease (AD) and may moderate the effects of donepezil. Objective: To build a personalized prediction model for patients with AD and to estimate patient-specific treatment effects of donepezil, using individual patient characteristics. Methods: We systematically searched for all double-masked randomized controlled trials comparing oral donepezil and pill placebo in the treatment of AD and requested individual participant data through its developer, Eisai. The primary outcome was cognitive function at 24 weeks, measured with the Alzheimer’s Disease Assessment Scale-cognitive component (ADAS-cog). We built a Bayesian meta-analytical prediction model for patients receiving placebo and we performed an individual patient data meta-analysis to estimate patient-level treatment effects. Results: Eight studies with 3,156 participants were included. The Bayesian prediction model suggested that more severe cognitive and global function at baseline and younger age were associated with worse cognitive function at 24 weeks. The individual participant data meta-analysis showed that, on average, donepezil was superior to placebo in cognitive function (ADAS-cog scores, –3.2; 95% Credible Interval (CrI) –4.2 to –2.1). In addition, our results suggested that antipsychotic drug use at baseline might be associated with a lower effect of donepezil in ADAS-cog (2.0; 95% CrI, –0.02 to 4.3). Conclusion: Although our results suggested that donepezil is somewhat efficacious for cognitive function for most patients with AD, use of antipsychotic drugs may be associated with lower efficacy of the drug. Future research with larger sample sizes, more patient covariates, and longer treatment duration is needed.

New Possibilities in the Therapeutic Approach to Alzheimer’s Disease

Despite the fact that Alzheimer’s disease (AD) is the most common cause of dementia, after many years of research regarding this disease, there is no casual treatment. Regardless of the serious public health threat it poses, only five medical treatments for Alzheimer’s disease have been authorized, and they only control symptoms rather than changing the course of the disease. Numerous clinical trials of single-agent therapy did not slow the development of disease or improve symptoms when compared to placebo. Evidence indicates that the pathological alterations linked to AD start many years earlier than a manifestation of the disease. In this pre-clinical period before the neurodegenerative process is established, pharmaceutical therapy might prove invaluable. Although recent findings from the testing of drugs such as aducanumab are encouraging, they should nevertheless be interpreted cautiously. Such medications may be able to delay the onset of dementia, significantly lowering the prevalence of the disease, but are still a long way from having a clinically effective disease-modifying therapy.

A Multinational, Multicenter, Randomized, Double-Blind, Active Comparator, Phase III Clinical Trial to Evaluate the Efficacy and Safety of Donepezil Transdermal Patch in Patients With Alzheimer's Disease

Background and Purpose

Oral administration of cholinesterase inhibitors is often associated with adverse gastrointestinal effects, and so developing an alternative administration route, such as transdermal, is urgently needed. The primary objective of this study was to determine the efficacy and safety of the IPI-301 donepezil transdermal patch compared with donepezil tablets (control) in mild-to-moderate probable Alzheimer’s disease (AD).

Methods

This prospective, randomized, double-blind, double-dummy, two-arm parallel, multicenter trial included 399 patients, among whom 303 completed the trial. For randomization, the patients were stratified based on previous treatment and donepezil dose; patients in each stratum were randomized to the test and control groups at a 1:1 ratio.

Results

The difference between the control group and the IPI-301 group, quantified as the Hodges–Lehmann estimate of location shift, was 0.00 (95% confidence interval: -1.00 to 1.33), with an upper limit of less than 2.02. The change in Alzheimer’s Disease Cooperative Study–Activities of Daily Living (ADCS-ADL) score differed significantly between the IPI-301 and control groups (p=0.02). However, the changes in the full-itemized ADCS-ADL scores at week 24 did not differ significantly between the two groups. There were no differences between the two groups regarding the scores for the Clinician Interview-Based Impression of Change (p=0.9097), Mini-Mental State Examination (p=0.7018), Neuropsychiatric Inventory (p=0.7656), or Clinical Dementia Rating (p=0.9990). Adverse events, vital signs, and laboratory test results were comparable between the two groups.

Conclusions

IPI-301 was safe and efficacious in improving cognitive function in patients with mild-to-moderate AD.

CRISPR-Cas9 treatment partially restores amyloid-β 42/40 in human fibroblasts with the Alzheimer's disease PSEN 1 M146L mutation

Presenilin 1 (PS1) is a central component of γ-secretase, an enzymatic complex involved in the generation of the amyloid-β (Aβ) peptide that deposits as plaques in the Alzheimer's disease (AD) brain. The M146L mutation in the PS1 gene (PSEN1) leads to an autosomal dominant form of early-onset AD by promoting a relative increase in the generation of the more aggregation-prone Aβ42. This change is evident not only in the brain but also in peripheral cells of mutation carriers. In this study we used the CRISPR-Cas9 system from Streptococcus pyogenes to selectively disrupt the PSEN1 M146L allele in human fibroblasts. A disruption of more than 50% of mutant alleles was observed in all CRISPR-Cas9-treated samples, resulting in reduced extracellular Aβ42/40 ratios. Fluorescence resonance energy transfer-based conformation and western blot analyses indicated that CRISPR-Cas9 treatment also affects the overall PS1 conformation and reduces PS1 levels. Moreover, our guide RNA did not lead to any detectable editing at the highest-ranking candidate off-target sites identified by ONE-seq and CIRCLE-seq. Overall, our data support the effectiveness of CRISPR-Cas9 in selectively targeting the PSEN1 M146L allele and counteracting the AD-associated phenotype. We believe that this system could be developed into a therapeutic strategy for patients with this and other dominant mutations leading to early-onset AD.

Long-Term Effect of Acetylcholinesterase Inhibitors on the Dorsal Attention Network of Alzheimer’s Disease Patients: A Pilot Study Using Resting-State Functional Magnetic Resonance Imaging

Background

Alzheimer’s disease (AD) is the most common condition of all neurodegenerative diseases and is characterized by various cognitive dysfunctions. Recent resting-state functional magnetic resonance imaging (rs-fMRI) studies have revealed the physiological dynamics of functionally connected brain networks, which are called resting-state networks (RSNs). Associations between impairments of RSNs and various neuropsychiatric diseases, such as AD, have been reported. Acetylcholinesterase inhibitors (AChEIs) have been used as a pharmacological treatment for mild-to-moderate moderate AD, and short-term improvements in cognitive functions and RSNs in restricted areas have been reported.

Objective

We aimed to characterize AChEI-related RSN changes by acquiring two sets of rs-fMRI data separated by approximately 3 to 6 months.

Methods

Seventeen patients with AD and nine healthy subjects participated in this study. Independent component analysis was performed on the rs-fMRI data of AChEI-responsive and non-responsive AD patients, stratified according to change in Mini-Mental State Examination (MMSE) scores after 3 to 6 months of AChEI therapy. In addition, a region of interest-based analysis of the rs-fMRI data before therapy was performed to explore the functional connectivity (FC) changes associated with AchEI therapy.

Results

Responders showed a significantly greater increase in MMSE scores, especially for orientation for time, than that of non-responders following AChEI therapy. A subtraction map of MMSE score differences (responders minus non-responders) in the independent component analysis revealed higher FC of the dorsal attention network in responders compared with that in non-responders. Moreover, in the region of interest analysis of untreated status data, the dorsal attention network showed significant negative FC with the right planum temporale, which belongs to the ventral attention network, proportional to MMSE score change.

Conclusion

The negative correlation of the FC of the dorsal attention network and right planum temporale before AChEI therapy and MMSE score change may be a biomarker of the therapeutic effect of AChEIs for AD.

Cognitive impairment networks in Alzheimer's disease: Analysis of three double-blind randomized, placebo-controlled, clinical trials of donepezil

Psychometric network analysis is an alternative theoretically-driven analytic approach that has the potential to conceptualize cognitive impairment in Alzheimer's disease differently than was previously assumed and consequently detect unknown treatment effects. Based on individual participant data, extracted from three double-blind, randomized placebo-controlled clinical trials, psychometric networks were computed on observed Alzheimer's Disease Assessment Scale Cognitive Subscale scores at baseline (N=1,554) and on predicted change scores at 24 weeks of follow-up for participants who received donepezil (N=797) or placebo (N=484). A novel conceptualization of cognitive impairment in Alzheimer's disease was displayed through the baseline network, that had 90% (n=27) positive statistically significant (p<0.05) associations, and a most central aspect of ideational praxis. Following 24 weeks, treatment effects emerged via the differences between the change score networks. The donepezil network had more statistically significant (p<0.05) positive associations and a higher global strength (n=15; S=1.22; p=0.03), than the placebo network (n=8; S=0.57). This suggests that for those who were treated with donepezil compared with placebo, cognition is a more unified construct. The main aspects of change in cognitive impairment were comprehension of spoken language for the donepezil network and spoken language ability for the placebo network. Comprehension of spoken language apears to be most sensitive to psychopharmaceutical interventions and should therefore be closely monitored. Overall, our psychometric network analysis presents a new conceptualization of cognitive impairment in Alzheimer's disease, points to previously unknown treatment effects and highlights well-defined aspects of cognitive impairment  that may translate into future treatment targets.

A prospective multicenter validation study of a machine learning algorithm classifier on quantitative electroencephalogram for differentiating between dementia with Lewy bodies and Alzheimer’s dementia

Background and purpose

An early and accurate diagnosis of Dementia with Lewy bodies (DLB) is critical because treatments and prognosis of DLB are different from Alzheimer’s disease (AD). This study was carried out in Japan to validate an Electroencephalography (EEG)-derived machine learning algorithm for discriminating DLB from AD which developed based on a database of EEG records from two different European countries.

Methods

In a prospective multicenter study, patients with probable DLB or with probable AD were enrolled in a 1:1 ratio. A continuous EEG segment of 150 seconds was recorded, and the EEG data was processed using MC-004, the EEG-based machine learning algorithm, with all clinical information blinded except for age and gender.

Results

Eighteen patients with probable DLB and 21 patients with probable AD were the included for the analysis. The performance of MC-004 differentiating probable DLB from probable AD was 72.2% (95% CI 46.5–90.3%) for sensitivity, 85.7% (63.7–97.0%) for specificity, and 79.5% (63.5–90.7%) for accuracy. When limiting to subjects taking ≤5 mg donepezil, the sensitivity was 83.3% (95% CI 51.6–97.9), the specificity 89.5% (66.9–98.7), and the accuracy 87.1% (70.2–96.4).

Conclusions

MC-004, the EEG-based machine learning algorithm, was able to discriminate between DLB and AD with fairly high accuracy. MC-004 is a promising biomarker for DLB, and has the potential to improve the detection of DLB in a diagnostic process.

Acetylcholinesterase inhibitors to enhance recovery from traumatic brain injury: a comprehensive review and case series

OBJECTIVE

Acetylcholinesterase inhibitors (AChEIs) are used off-label, in both adult and pediatric patients, to help further neuro-recovery after traumatic brain injury (TBI). Evidence is limited and piecemeal. This review describes how TBI affects the cholinergic system and consolidates evidence supporting or refuting the use of AChEIs following TBI.

METHODS

NCBI MEDLINE search included all articles published through March 2021 on AChEI use in acute and post-acute adult TBI rehabilitation (treatment began <90 days or ≥90 days since injury, respectively), and in pediatric TBI rehabilitation. Further, we checked ClinicalTrials.gov for ongoing trials using AChEIs for TBI rehabilitation in the United States.

RESULTS

27 original articles from NCBI Medline, published through March 2021, were included. The use of AChEIs following TBI in acute and post-acute rehabilitation settings, in both adult and pediatric patients, along with medication side effects, is discussed.

CONCLUSIONS

Most studies showed benefits with only moderate effect sizes because of small sample sizes. Reported side effects are minimal and stop soon after AChEIs is discontinued. Conclusions are limited by paucity of research; but fortunately, a large randomized controlled trial is ongoing, and more are needed to truly determine the efficacy of AChEIs in helping with recovery from TBI.

Model-Based Equivalent Dose Optimization to Develop New Donepezil Patch Formulation

Donepezil patch was developed to replace the original oral formulation. To accurately describe the pharmacokinetics of donepezil and investigate compatible doses between two formulations, a population pharmacokinetic model for oral and transdermal patches was built based on a clinical study. Plasma donepezil levels were analyzed via liquid chromatography/tandem mass spectrometry. Non-compartmental analyses were performed to derive the initial parameters for compartmental analyses. Compartmental analysis (CA) was performed with NLME software NONMEM assisted by Perl-speaks-NONMEM, and R. Model evaluation was proceeded via visual predictive checks (VPC), goodness-of-fit (GOF) plotting, and bootstrap method. The bioequivalence test was based on a 2 × 2 crossover design, and parameters of AUC and C_max were considered. We found that a two-compartment model featuring two transit compartments accurately describes the pharmacokinetics of nine subjects administered in oral, as well as of the patch-dosed subjects. Through evaluation, the model was proven to be sufficiently accurate and suitable for further bioequivalence tests. Based on the bioequivalence test, 114 mg/101.3 cm²–146 mg/129.8 cm² of donepezil patch per week was equivalent to 10 mg PO donepezil per day. In conclusion, the pharmacokinetic model was successfully developed, and acceptable parameters were estimated. However, the size calculated by an equivalent dose of donepezil patch could be rather large. Further optimization in formulation needs to be performed to find appropriate usability in clinical situations.

Herbal Mixture of Carthamus tinctorius L. Seed and Taraxacum coreanum Attenuates Amyloid Beta-Induced Cognitive Dysfunction In Vivo

Deposition of amyloid-beta (Aβ) in the aging brain has been often observed and is thought to be a pathological feature of Alzheimer’s disease. The use of natural products for disease prevention and treatment is gaining attention worldwide. Carthamus tinctorius L. seed and Taraxacum coreanum have been used as traditional medicines in Asian countries, where they have been reported to exert anti-inflammatory and anti-oxidative effects. It has been demonstrated that the combination of C. tinctorius L. seed and T. coreanum has an effect on cognitive enhancement, indicating a ratio of 5:5 synergistically enhancing learning and memory abilities in comparison with a single treatment. Here, we aimed to investigate the protective effect of C. tinctorius L. seed and T. coreanum mixture (CT) at different concentrations on cognition in Aβ_25-35-infused mice. CT-administered mice showed significant cognitive improvement in the T-maze, novel object recognition, and Morris water maze tests. Moreover, amyloidogenesis-related proteins, such as β-secretase and γ-secretase, were detected and their protein levels decreased after treatment with CT. Our study shows that CT attenuates cognitive dysfunction by improving learning and memory capability and regulating Aβ-related proteins in Aβ_25-35-injected mice. These findings suggest that CT might be a candidate for functional food on cognitive improvement.

Effects of water‐soluble mangosteen extract on cognitive function and neuropsychiatric symptoms in patients with mild to moderate Alzheimer's disease (WECAN‐AD): A randomized controlled trial

Introduction

The water‐soluble mangosteen pericarp extract's (WME) effect was investigated in Alzheimer's disease (AD).

Methods

The participants received 4 mg/kg/day of WME for 24 weeks (low dose, n = 33), 4 mg/kg/day for 12 weeks and then 8 mg/kg/day for 12 weeks (high dose, n = 33); or a placebo (n = 42). The outcomes were neuropsychiatric test scores, safety, tolerability, and the blood 4‐hydroxynonenal level.

Results

The proportion of participants who achieved the minimum clinically important difference for the Alzheimer's Disease Assessment Scale–Cognitive Subscale (ADAS‐Cog; –2.6 points) at 24 weeks was significantly higher in the low‐dose group (and a trend in the high‐dose group) than in the placebo group. WME appeared safe and well tolerated. At 24 weeks, the 4‐hydroxynonenal level declined in both intervention groups. The participants with a 5% reduction in this level showed greater ADAS‐Cog improvements.

Conclusion

WME is a safe and well‐tolerated cognitive enhancer in AD with varying benefits across individuals based on antioxidative response.

Sex differences in Alzheimer's disease: do differences in tau explain the verbal memory gap?

To determine if sex differences in verbal memory in AD are related to differences in extent or distribution of pathological tau, we studied 275 participants who were amyloid PET positive and carried clinical classifications of normal cognition, mild cognitive impairment (MCI) or dementia, and had tau (AV1451) PET. We compared tau distribution between men and women, and as a function of genetic risk. In MCI we further explored the relationship between quantity and distribution of tau in relation to verbal memory scores. Women had more tau burden overall, but this was driven by sex differences at the MCI stage. There was no significant difference in tau load by APOE e4 status. Within the MCI group the association between tau and performance in verbal memory tasks was stronger in women than men. The topography of the associations between tau and verbal memory also differed in MCI; women demonstrated stronger relationships between tau distribution and verbal memory performance, especially in the left hemisphere. These findings have implications for understanding tau distribution and spread, and in interpretation of verbal memory performance.

Long-acting injectable donepezil microspheres: Formulation development and evaluation

Novel formulations of donepezil (DNP)-loaded microspheres based on a bio-degradable polymer of poly(lactic-co-glycolic acid) (PLGA) with a one-month duration of effect were developed, aimed at reducing dosing frequency and adverse effects and improving patient adherence. The spherical and monodispersed DNP-loaded microspheres were precisely fabricated by the Inventage Lab Precision Particle Fabrication method (IVL-PPFM®) based on micro-electromechanical systems (MEMS) and microfluidic technology. The types of polymers and end-groups, the drug/polymer ratio (DPR), and the routes of administration for DNP were studied to ensure an effective concentration and desired duration. Laser-light particle size analysis and scanning electron microscopy were used to characterization. Also, non-clinical animal models of beagle dogs are used to optimize DNP formulations and evaluate their pharmacokinetic properties. The PK results showed that the DPR was a critical factor in determining the exposure level and duration of DNR release. Furthermore, the lactide ratio, which varied depending upon the type of polymer, determined the hydrophobic interaction and was also an important factor affecting the desired DNP release. Since DNP shows a large inter-species variation between dogs and humans, PK modeling and simulation of the reference drug (i.e., Aricept®) and DNP-loaded microspheres were used for formulation development to overcome and interpret these variations. In addition, the developed PK model was extrapolated to humans using the estimated PK parameter and published clinical pharmacology data for DNP. The predicted PK profile of the DNP-loaded microsphere in humans showed that the formulation with PLGA 7525A and the DPR of 1/9 could maintain drug concentration for a month and could control initial burst release. The data obtained from the study could be used as scientific evidence for decision-making in future formulation development.

Adverse Drug Reactions of Acetylcholinesterase Inhibitors in Older People Living with Dementia: A Comprehensive Literature Review

The rising of global geriatric population has contributed to increased prevalence of dementia. Dementia is a neurodegenerative disease, which is characterized by progressive deterioration of cognitive functions, such as judgment, language, memory, attention and visuospatial ability. Dementia not only has profoundly devastating physical and psychological health outcomes, but it also poses a considerable healthcare expenditure and burdens. Acetylcholinesterase inhibitors (AChEIs), or so-called anti-dementia medications, have been developed to delay the progression of neurocognitive disorders and to decrease healthcare needs. AChEIs have been widely prescribed in clinical practice for the treatment of Alzheimer's disease, which account for 70% of dementia. The rising use of AChEIs results in increased adverse drug reactions (ADRs) such as cardiovascular and gastrointestinal adverse effects, resulting from overstimulation of peripheral cholinergic activity and muscarinic receptor activation. Changes in pharmacokinetics (PK), pharmacodynamics (PD) and pharmacogenetics (PGx), and occurrence of drug interactions are said to be major risk factors of ADRs of AChEIs in this population. To date, comprehensive reviews in ADRs of AChEIs have so far been scarcely studied. Therefore, we aimed to recapitulate and update the diverse aspects of AChEIs, including the mechanisms of action, characteristics and risk factors of ADRs, and preventive strategies of their ADRs. The collation of this knowledge is essential to facilitate efforts to reduce ADRs of AChEIs.

Linking the Clinical Dementia Rating Scale-Sum of Boxes, the Clinician's Interview-Based Impression Plus Caregiver Input, and the Clinical Global Impression Scale: Evidence based on Individual Participant Data from Five Randomized Clinical Trials of Donepezil

BACKGROUND

In patients with Alzheimer's disease, global assessment scales, such as the Clinical Dementia Rating-Sum of Boxes (CDR-SB), the Clinician's Interview-Based Impression Plus Caregiver Input (CIBI plus), and the Clinical Global Impression (CGI) are commonly used.

OBJECTIVE

To clinically understand and interpret the associations between these scales, we examined the linkages for the total and change scores of CDR-SB, CIBI plus, and CGI.

METHODS

Individual participant data (N = 2,198) from five pivotal randomized placebo-controlled trials of donepezil were included. Data were collected at baseline and scheduled visits for up to 6 months. Spearman's correlation coefficients ρ were examined between corresponding total and change scores of simultaneous CDR-SB, CIBI plus, and CGI ratings. To link between the simultaneous ratings, equipercentile linking was used.

RESULTS

We found strong evidence that the Spearman's correlation coefficients between the CDR-SB and CGI, and CDR-SB and CIBI plus total scores were at least adequately correlated (ρ= 0.50 to 0.71, with p < 0.01). The correlation coefficients between the change scores of CDR-SB and CGI were deemed adequate for weeks 6 to 24 (ρ= 0.44 to 0.65); the remaining correlations were smaller in magnitude (ρ= 0.09 to 0.35). Overall, the linkages were in-line with expectations, e.g., CDR-SB range score of 3-4 (= very mild dementia) was linked to a CGI score of 3 (= mildly ill), and an increase of CDR-SB of 1 was linked to a change of 5 (= minimal worsening) in both CGI and CIBI plus.

CONCLUSION

The study findings can be useful for clinicians wishing to compare scores of different scales across patients. They can also help researchers understand results of studies using different scales and can facilitate meta-analyses, to increase statistical power.

Converting from the Montreal Cognitive Assessment to the Mini-Mental State Examination-2

OBJECTIVE

The Montreal Cognitive Assessment (MoCA) and Mini-Mental State Examination-2 (MMSE-2) are useful psychometric tests for cognitive screening. Many clinicians want to predict the MMSE-2 score based on the MoCA score. To facilitate the transition from the MoCA to the MMSE-2, this study developed a conversion method.

METHODS

This study retrospectively examined the relationship between the MoCA and MMSE-2. Overall, 303 participants were evaluated. We produced a conversion table using the equipercentile equating method with log-linear smoothing. Then, we evaluated the reliability and accuracy of this algorithm to convert the MoCA to the MMSE-2.

RESULTS

MoCA scores were converted to MMSE-2 scores according to a conversion table that achieved a reliability of 0.961 (intraclass correlation). The accuracy of this algorithm was 84.5% within 3 points difference from the raw score.

CONCLUSIONS

This study reports a reliable and easy conversion algorithm for transforming MoCA scores into converted MMSE-2 scores. This method will greatly enhance the utility of existing cognitive data in clinical and research settings.

Preventive effect of Ninjin-yoei-to, a Kampo medicine, on amyloid β1-42-induced neurodegeneration via intracellular Zn2+ toxicity in the dentate gyrus

Ninjin-yoei-to (NYT), a Kampo medicine, has ameliorative effects on cognitive dysfunction via enhancing cholinergic neuron activity. To explore an efficacy of NYT administration for prevention and cure of Alzheimer’s disease, here we examined the effect of NYT on amyloid β_1-42 (Aβ_1-42)-induced neurodegeneration in the dentate gyrus. A diet containing 3% NYT was administered to mice for 2 weeks and human Aβ_1-42 was intracerebroventricularly injected. Neurodegeneration in the dentate granule cell layer of the hippocampus, which was determined 2 weeks after the injection, was rescued by administration of the diet for 4 weeks. Aβ staining (uptake) was not modified in the dentate granule cell layer by pre-administration of the diet for 2 weeks, while Aβ_1-42-induced increase in intracellular Zn²⁺ was reduced, suggesting that pre-administration of NYT prior to Aβ injection is effective for reducing Aβ_1-42-induced Zn²⁺ toxicity in the dentate gyrus. As a matter of fact, Aβ_1-42-induced neurodegeneration in the dentate gyrus was rescued by pre-administration of NYT. Interestingly, the level of metallothioneins, intracellular Zn²⁺-binding proteins, which can capture Zn²⁺ from Zn-Aβ_1-42 complexes, was elevated in the dentate granule cell layer by pre-administration of NYT. The present study suggests that pre-administration of NYT prevents Aβ_1-42-mediated neurodegeneration in the dentate gyurs by induced synthesis of metallothioneins, which reduces intracellular Zn²⁺ toxicity induced by Aβ_1-42.

Mixed dementia and hyperactive delirium: a diagnostic challenge

It is well recognised that acute confusion or delirium complicates up to 10% of acute medical admissions. Disorientation in time and place with an impaired short-term memory and conscious level are the hallmarks of an acute confusion. In delirium, disorders of perception may produce restlessness and agitation. A similar state during the final days of life is termed 'terminal delirium'. Less than 10% of affected individuals will have a primary neurological disorder, for example, dementia, a neurodegenerative disease with varying aetiologies. Currently there are at least 50 million people globally suffering from dementia rendering it a global healthcare problem. Mixed dementia (MD) can be defined as a cognitive decline sufficient to impair independent functioning in daily life resulting from the coexistence of Alzheimer's disease (AD) and cerebrovascular pathology. MD occurs in patients with a neurodegenerative disorder, such as AD, Lewy body or Pick's disease and additionally cerebrovascular disease. The mechanistic synergisms between the coexisting pathologies affecting dementia risk, progression and the ultimate clinical manifestations remain elusive. Although AD can be diagnosed with a considerable degree of accuracy, the distinction between isolated AD, vascular dementia and MD, when both pathologies coexist in the same patient remains one of the most difficult diagnostic challenges because their clinical presentation can overlap. Neuropathological studies indicate that mixed vascular Alzheimer's dementia (MD) has a prevalence of 22% in the elderly. The authors present the case of a 78-year-old man with a diagnosis of MD presenting to the emergency department with delirium, a common but serious acute neuropsychiatric syndrome with the core features of inattention and global cognitive dysfunction. This case demonstrates the challenges in establishing a diagnosis in patients presenting with MD and shows that a cognitive assessment at presentation in a delirious state offers very little diagnostic information. It is therefore suggested to conduct a routine cognitive function examination on patients with dementia to anticipate new neurological signs and/or symptoms thus allowing earlier diagnosis and treatment. However, a baseline cognitive assessment when the patient was well, duration and nature of deterioration as well as collateral history will help differentiate delirium from an underlying dementia.