Monotherapy Is Good Enough for Patients With Mild‐to‐Moderate Alzheimer's Disease: A Network Meta‐Analysis of 76 Randomized Controlled Trials

Memantine: Updating a rare success story in pro-cognitive therapeutics

The great potential for NMDA receptor modulators as druggable targets in neurodegenerative disorders has been met with limited success. Considered one of the rare exceptions, memantine has consistently demonstrated restorative and prophylactic properties in many AD models. In clinical trials memantine slows the decline in cognitive performance associated with AD. Here, we provide an overview of the basic properties including pharmacological targets, toxicology and cellular effects of memantine. Evidence demonstrating reductions in molecular, physiological and behavioural indices of AD-like impairments associated with memantine treatment are also discussed. This represents both an extension and homage to Dr. Chris Parson's considerable contributions to our fundamental understanding of a success story in the AD treatment landscape.

Efficacy of pharmacotherapy and non-pharmacotherapy of Alzheimer dementia: A protocol for systematic review and meta-analysis

BACKGROUND

Alzheimer disease (AD) is the most common cause of dementia worldwide. Despite the publication of numerous systematic reviews and meta-analyses that have summarized the evidence associated with pharmacotherapies (PTs) and non-pharmacotherapies (NPTs) for the wide range of interventions available for AD treatment, their comparative safety and efficacy remains insufficiently defined.

METHODS

Systematic reviews of randomized controlled trials (RCTs) will be selected according to the following criteria: conducted in elderly patients aged 60 years or older with AD living in community or institutionalized settings, applied pairwise meta-analysis (PMA) or network meta-analysis (NMA) approaches providing pooled relative treatment effects for at least 1 pair of PTs or NPTs, and providing at least 1 of the following outcomes for patients/caregivers: cognitive, functional status, behavior, quality of life (QoL), and caregiver stress or burden. All article screening, data extraction, and risk of bias assessment will be completed independently by 2 reviewers. Relative treatment rankings will be reported with mean ranks and surface under the cumulative ranking curves.

RESULTS AND CONCLUSION

We will determine the most efficacious treatment strategies for AD patients from the most highly ranked treatments. These results will help to guide clinical decision-making and improve patient care.

Pharmacotherapy of Alzheimer's disease: an overview of systematic reviews

BACKGROUND

Alzheimer's disease (AD) is a neurodegenerative disease and the most common cause of dementia. In this umbrella systematic review (SR), we summarized the efficacy of different pharmacological interventions in improving cognitive function in patients with AD.

METHODS

A systematic search was performed through the PubMed, Scopus, Embase, and Cochrane databases for SRs of studies assessing the efficacy of pharmacological interventions versus placebo in improving cognitive function in AD or mild cognitive impairment due to AD. The risk of bias (RoB) was assessed using the Risk of Bias in SRs (ROBIS) tool.

RESULTS

Out of 1748 articles found through the database survey, 33 SR articles were included. These studies assessed effects of immunotherapy, cholinesterase inhibitors (ChEIs), memantine, statins, lithium, nonsteroidal anti-inflammatory drugs (NSAIDs), antidiabetic agents, Cerebrolysin, RAS-targeting antihypertensive drugs (ARBs and ACEIs), psychostimulants, glycogen synthase kinase 3 (GSK-3) inhibitors, melatonin, and herbal medications on cognitive function in AD patients. There was no notable overall RoB in 18 studies (54.5%), the RoB in 14 studies (42.4%) was high, and in one study (3.0%) it was unclear.

CONCLUSIONS

The use of ChEIs, including rivastigmine, galantamine, and donepezil, as well as memantine has demonstrated a positive impact on improving cognitive outcomes of AD patients, but no considerable effects were found for immunotherapies. Melatonin, statins, antihypertensive drugs, antidiabetic agents, Cerebrolysin, psychostimulants, and some herbal drugs such as Danggui-Shaoyao-San and Ginkgo biloba seem to be effective in improving cognitive function of AD patients, but the evidence in this regard is limited.

The Efficacy and Safety of Alzheimer's Disease Therapies: An Updated Umbrella Review

BACKGROUND

Evidence summaries for efficacy and safety of frequently employed treatments of Alzheimer's disease (AD) are sparse.

OBJECTIVE

We aimed to perform an updated umbrella review to identify an efficacious and safe treatment for AD patients.

METHODS

We conducted a search for meta-analyses and systematic reviews on the Embase, PubMed, The Cochrane Library, and Web of Science to address this knowledge gap. We examined the cognitive functions, behavioral symptoms, global clinical assessment, and Activities of Daily Living as efficacy endpoints, and the incidence of adverse events as safety profiles.

RESULTS

Sixteen eligible papers including 149 studies were included in the umbrella review. The results showed that AChE inhibitors (donepezil, galantamine, rivastigmine, Huperzine A), Ginkgo biloba, and cerebrolysin appear to be beneficial for cognitive, global performances, and activities of daily living in patients with AD. Furthermore, anti-Aβ agents are unlikely to have an important effect on slowing cognitive or functional impairment in mild to moderate AD.

CONCLUSION

Our study demonstrated that AChE inhibitors, Ginkgo biloba, and cerebrolysin are the optimum cognitive and activities of daily living medication for patients with AD.

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.

Sixteen-Week Interventional Study to Evaluate the Clinical Effects and Safety of Rivastigmine Capsules in Chinese Patients with Alzheimer's Disease

BACKGROUND

Rivastigmine is a cholinesterase inhibitor, approved for the treatment of mild-to-moderate dementia of Alzheimer's type.

OBJECTIVE

To explore the efficacy and safety of the maximal tolerated dose of rivastigmine capsules in Chinese patients with mild-to-moderate Alzheimer's disease (AD).

METHODS

The study was a multicenter, open-label, single-arm, phase IV clinical study in mild-to-moderate drug-naïve AD patients treated with rivastigmine capsules. The primary endpoint was the changes in the total scores of Alzheimer's Disease Assessment Scale-Cognitive subscale (ADAS-Cog) from baseline to week 16. Secondary endpoints included changes in the scores of the following assessment scales and safety: Alzheimer's Disease Cooperative Study; Activities of Daily Living; Mini-Mental Status Examination (MMSE); Neuropsychiatry Index (NPI), and Caregiver Burden Inventory.

RESULTS

222 patients were enrolled. Of these, 136 (75.1%) patients received and maintained the effective dose (≥6 mg/d) of rivastigmine for at least 4 weeks. The ADAS-Cog scale score improved in rivastigmine-treated patients at week 16 compared with baseline (p < 0.001) by 2.0 (95% CI: -3.0 to -1.1) points, which met the pre-defined superiority criteria. NPI-10 and NPI-12 scores improved by 3.6 and 4.0 points at week 16 (p = 0.001, p < 0.001), respectively. A total of 107 patients (59.1%) experienced adverse effects (AEs) during the study; common AEs included nausea (20.5%), vomiting (16.6%), anorexia (7.8%), dizziness (7.7%), and diarrhea (7.2%).

CONCLUSION

This was the first phase IV study on rivastigmine in mainland China. The study preliminarily demonstrated that rivastigmine capsules showed good tolerability and efficacy in mild-to-moderate AD patients with the maximal tolerated dose.

Efficacy and Safety of Cholinesterase Inhibitors for Mild Cognitive Impairment:A Systematic Review and Meta-Analysis

BACKGROUND

The clinical benefit of cholinesterase inhibitors (ChEIs) for mild cognitive impairment (MCI) remains inconclusive.

OBJECTIVE

We performed a systematic review and meta-analysis of the efficacy/safety of ChEIs on subjects with MCI.

METHODS

We included randomized controlled trials (RCTs) of ChEIs in subjects with MCI, using cognitive function scores as a primary outcome measure.

RESULTS

Fourteen RCTs (six using donepezil, four using galantamine, and four using rivastigmine) with 5,278 subjects were included. We found no significant difference in cognitive function scores between the ChEIs and placebo groups [standardized mean difference (SMD) = -0.06, p = 0.38, I2 = 76% ]. However, in the secondary outcomes, ChEIs were associated with a lower incidence of progression to dementia compared with placebo (risk ratio = 0.76, the number needed to treat = 20). For safety outcomes, ChEIs were associated with a lower prevalence of fall than placebo. On the other hand, compared with placebo, ChEIs were associated with a higher incidence of discontinuation due to all causes, discontinuation due to adverse events, at least one adverse event, abnormal dreams, diarrhea, dizziness, headache, insomnia, loose stools, muscle cramps, nausea, vomiting, and weight loss.

CONCLUSIONS

Although ChEIs have a slight efficacy in the treatment of MCI, there are many safety issues. Therefore, ChEIs are difficult to recommend for MCI. However, the efficacy and safety of ChEIs on MCI with a biomarker-based diagnosis is unclear. Further RCTs are needed to confirm the efficacy and safety of ChEIs when used for individual neuropathological classifications of MCI.

Pharmacogenetic considerations when prescribing cholinesterase inhibitors for the treatment of Alzheimer's disease

INTRODUCTION

Cholinergic dysfunction, demonstrated in the late 1970s and early 1980s, led to the introduction of acetylcholinesterase inhibitors (AChEIs) in 1993 (Tacrine) to enhance cholinergic neurotransmission as the first line of treatment against Alzheimer's disease (AD). The new generation of AChEIs, represented by Donepezil (1996), Galantamine (2001) and Rivastigmine (2002), is the only treatment for AD to date, together with Memantine (2003). AChEIs are not devoid of side-effects and their cost-effectiveness is limited. An option to optimize the correct use of AChEIs is the implementation of pharmacogenetics (PGx) in the clinical practice.

AREAS COVERED

(i) The cholinergic system in AD, (ii) principles of AD PGx, (iii) PGx of Donepezil, Galantamine, Rivastigmine, Huperzine and other treatments, and (iv) practical recommendations.

EXPERT OPINION

The most relevant genes influencing AChEI efficacy and safety are APOE and CYPs. APOE-4 carriers are the worst responders to AChEIs. With the exception of Rivastigmine (UGT2B7, BCHE-K), the other AChEIs are primarily metabolized via CYP2D6, CYP3A4, and UGT enzymes, with involvement of ABC transporters and cholinergic genes (CHAT, ACHE, BCHE, SLC5A7, SLC18A3, CHRNA7) in most ethnic groups. Defective variants may affect the clinical response to AChEIs. PGx geno-phenotyping is highly recommended prior to treatment.

Different Doses of Pharmacological Treatments for Mild to Moderate Alzheimer's Disease: A Bayesian Network Meta-Analysis

Background

Pharmacological treatments play a significant role in treating mild to moderate Alzheimer's disease (AD), but the optimal doses of various drugs used for these treatments are unknown. Our study compared the efficacy, acceptability, and safety of different doses of pharmacological treatments for mild to moderate AD.

Methods

Randomized controlled trials (RCTs) were identified by searching the PubMed, EMBASE, and Cochrane Library databases (all RCTs published from the date of inception of the databases until September 19, 2019). Trials comparing the efficacy, acceptability, and safety of pharmacological interventions involving donepezil, galantamine, rivastigmine, memantine, huperzine A, and Ginkgo biloba extract EGb761, alone or in combination, were identified. The primary outcomes were efficacy, acceptability, and safety.

Results

Our meta-analysis included 37 studies involving 14,705 participants. In terms of improving cognitive function, galantamine 32 mg, galantamine 24 mg, donepezil 5 mg, and donepezil 10 mg were more effective than other interventions, with the surface under the cumulative ranking curve (SUCRA) values of 93.2, 75.5, 73.3, and 65.6%, respectively. According to the SUCRA values, EGb761 240 mg was considered to be the optimal intervention in terms of both acceptability and safety. With regard to clinical global impression, rivastigmine 12 mg had the highest probability of being ranked first (83.7%). The rivastigmine 15 cm² patch (SUCRA = 93.7%) may be the best choice for daily living. However, there were no interventions that could significantly improve neuropsychiatric symptoms, compared with the placebo.

Conclusions

Different doses of the tested pharmacological interventions yielded benefits with regard to cognition, acceptability, safety, function, and clinical global impressions, but not effective behaviors.

Donepezil plus memantine versus donepezil alone for treatment of concomitant Alzheimer's disease and chronic obstructive pulmonary disease: a retrospective observational study

Objective

To assess the clinical outcomes of donepezil plus memantine (DM) and donepezil (DO) alone in Asian patients with a concomitant diagnosis of moderate-to-severe Alzheimer’s disease and mild-to-moderate chronic obstructive pulmonary disease (AD-COPD).

Methods

We conducted a retrospective analysis of patients with AD-COPD who received either DM or DO for 6 months, or until the occurrence of unacceptable adverse events or disease progression, between June 2012 and May 2016. The primary endpoint was the score on the Standardized Mini-Mental State Examination (SMMSE). Secondary endpoints were scores on the caregiver-rated Bristol Activities of Daily Living Scale, Neuropsychiatric Inventory, Dementia Quality of Life (DEMQOL)-Proxy, and General Health Questionnaire 12.

Results

In total, 154 eligible patients received DM, whereas 156 received DO. Compared with patients who received DO, patients who received DM had significantly higher mean scores on the SMMSE by 2.1 points (95% confidence interval, 1.3–2.5). Significant between-group heterogeneity was not detected in outcomes over time. The benefits of treatment with DM were greater than those of treatment with DO, in terms of the primary endpoint. Significant differences were also detected in terms of secondary endpoints.

Conclusion

DM is more effective than DO alone for Asian patients with AD-COPD.

Are antidementia drugs associated with reduced mortality after a hospital emergency admission in the population with dementia aged 65 years and older?

Introduction

People with dementia experience poor outcomes after hospital admission, with mortality being particularly high. There is no cure for dementia; antidementia medications have been shown to improve cognition and function, but their effect on mortality in real-world settings is little known. This study examines associations between treatment with antidementia medication and mortality in older people with dementia after an emergency admission.

Methods

The design is a retrospective cohort study of people aged ≥65 years, with a diagnosis of dementia and an emergency hospital admission between 01/01/2010 and 31/12/2016. Two classes of antidementia medication were considered: the acetylcholinesterase inhibitors and memantine. Mortality was examined using a Cox proportional hazards model with time-varying covariates for the prescribing of antidementia medication before or on admission and during one-year follow-up, adjusted for demographics, comorbidity, and community prescribing including anticholinergic burden. Propensity score analysis was examined for treatment selection bias.

Results

There were 9142 patients with known dementia included in this study, of which 45.0% (n = 4110) received an antidementia medication before or on admission; 31.3% (n = 2864) were prescribed one of the acetylcholinesterase inhibitors, 8.7% (n = 798) memantine, and 4.9% (n = 448) both. 32.9% (n = 1352) of these patients died in the year after admission, compared to 42.7% (n = 2148) of those with no antidementia medication on admission. The Cox model showed a significant reduction in mortality in patients treated with acetylcholinesterase inhibitors (hazard ratio [HR] = 0.78, 95% CI 0.72–0.85) or memantine (HR = 0.75, 95% CI 0.66–0.86) or both (HR = 0.76, 95% CI 0.68–0.94). Sensitivity analysis by propensity score matching confirmed the associations between antidementia prescribing and reduced mortality.

Discussion

Treatment with antidementia medication is associated with a reduction in risk of death in the year after an emergency hospital admission. Further research is required to determine if there is a causal relationship between treatment and mortality, and whether “symptomatic” therapy for dementia does have a disease-modifying effect.

•

Mortality in older people admitted with dementia is very high after an emergency hospital admission with about 40% of them dying within one year from admission.

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Less than half of patients admitted with dementia are in receipt of antidementia treatment on admission.

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Risk of death is reduced in patients treated with antidementia medication at the time of acute admission, which is not explained by their age, sex, comorbidities, or other drug prescribing.

Association of Antidementia Therapies With Time to Skilled Nursing Facility Admission and Cardiovascular Events Among Elderly Adults With Alzheimer Disease

Importance

To date, no study has compared time to skilled nursing facility (SNF) admission and cardiovascular events across medications available to treat Alzheimer disease.

Objective

To compare time to SNF admission and cardiovascular events between acetylcholinesterase inhibitor (AChEI) monotherapy, memantine hydrochloride monotherapy, and combination therapy with an AChEI and memantine in treating elderly adults with Alzheimer disease.

Design, Setting, and Participants

This retrospective cohort study uses January 1, 2006, to December 31, 2014, claims data from a 5% random sample of Medicare beneficiaries who had received a new diagnosis of Alzheimer disease between January 1, 2007, and December 31, 2013, and who initiated AChEI monotherapy, memantine monotherapy, or combination therapy with an AChEI and memantine (N = 73 475). Patients were followed up until discontinuation of treatment, switch of treatment, death, or the end of the study period. Statistical analysis was conducted from February 15, 2018, to June 15, 2018.

Exposures

Acetylcholinesterase inhibitor monotherapy (n = 44 424), memantine monotherapy (n = 11 809), and combination therapy with an AChEI and memantine (n = 17 242).

Main Outcomes and Measures

Primary outcomes were time to SNF admission and the composite of the following cardiovascular events: acute myocardial infarction, bradycardia, syncope, atrioventricular block, QT interval prolongation, and ventricular tachycardia. Cox proportional hazards regression models were constructed to compare outcomes between each pair of treatment groups, controlling for a comprehensive list of patient characteristics.

Results

The study population included 73 475 participants (53 068 women and 20 407 men; mean [SD] age, 81.8 [8.3] years); 25.5% of the participants initiating AChEI monotherapy, 25.6% of participants initiating memantine monotherapy, and 29.7% of participants initiating combination therapy with an AChEI and memantine were admitted to an SNF. Similarly, 22.2% of the participants initiating AChEI monotherapy, 20.0% of those initiating memantine monotherapy, and 24.5% of those initiating combination therapy experienced at least 1 cardiovascular event. No difference in time to SNF admission was found across the 3 treatment groups. The risk of the composite measure of any cardiovascular event did not differ between the combination therapy and AChEI monotherapy groups (adjusted hazard ratio [aHR], 0.99; 95% CI, 0.96-1.03); however, it was higher for both AChEI monotherapy (aHR, 1.07; 95% CI, 1.02-1.12) and combination therapy (aHR, 1.07; 95% CI, 1.01-1.12), relative to memantine monotherapy. This result was mainly driven by the lower risk of bradycardia and syncope observed for the memantine monotherapy group relative to both AChEI monotherapy (bradycardia: aHR, 0.88; 95% CI, 0.82-0.95; and syncope: aHR, 0.92; 95% CI, 0.86-0.97) and combination therapy (bradycardia: aHR, 0.89; 95% CI, 0.82-0.97; and syncope: aHR, 0.87; 95% CI, 0.83-0.94).

Conclusions and Relevance

Time to SNF admission did not differ across treatment groups, but memantine monotherapy was associated with a lower risk of cardiovascular events compared with both AChEI monotherapy and combination therapy with an AChEI and memantine.

Alzheimer's disease: some pharmacological and non-pharmacological approaches to correcting neuropsychiatric disorders

Today, there is no reliable pharmacological correction of dementia, despite its high prevalence worldwide. The clinical presentation of Alzheimer's disease at one or another stage is accompanied by neuropsychiatric disorders (NPDs) in addition to cognitive defect. The intensity and range of NPDs are different. The possibilities of drug therapy for NPDs are demonstrated. The role of akatinol memantine in correcting a number of psychological and behavioral disorders is highlighted. Biological, psychological, social, and environmental factors are identified among those that contribute to or provoke the development of NPDs. Knowledge of the triggers of mental disorders makes it possible to prevent and thereby reduce or eliminate NPDs. Special emphasis is laid on the patient-caregiver relationship. In recent years, non-pharmacological interventions have been increasingly used as priority-line therapy for NPDs. There are data on main methods for non-pharmacological correction and on the efficiency of their application.