Assessing therapeutic efficacy in a progressive disease: a study of donepezil in Alzheimer's disease

Efficacy of 5 and 10 mg donepezil in improving cognitive function in patients with dementia: a systematic review and meta-analysis

Objective

The purpose of this study was to compare donepezil at 5 mg and 10 mg/day against a placebo to systematically evaluate its effectiveness in improving cognitive function among patients suffering from dementia at any stage.

Method

For this systematic review and meta-analysis, we looked up Medline, Scopus, Embase, Web of Science, and The Cochrane Library for articles on the efficacy of donepezil in dementia published in the past 20 years and summarized the placebo and intervention data. Initially, a total of 2,272 articles were extracted using our search query and after the inclusion and exclusion criteria set for extraction of data, 18 studies were included in this review using PRISMA flowchart. The ADAS-cog and MMSE assessment scales were used for measuring the outcomes using IBM SPSS 29.0 for the meta-analysis.

Result

The meta-analysis comprised a total of 18 RCTs (randomized controlled trials) that were randomized to receive either donepezil 5 mg/day (n = 1,556), 10 mg/day (n = 2050) or placebo (n = 2,342). Meta-analysis concerning efficacy showed that donepezil at 10 mg/day significantly improved the MMSE score (g: 2.27, 95%CI: 1.25-3.29) but could not substantially reduce the ADAS-cog. At 5 mg/day donepezil, an overall slight improvement in MMSE score (Hedges' g: 2.09, 95%CI: 0.88-3.30) was observed.

Conclusion

Both donepezil 5 mg/day and 10 mg/day doses demonstrated improved cognitive functions for patients with dementia, however results indicated that the 10 mg/day dose was more efficacious.

Targeting NLRP3 inflammasome for neurodegenerative disorders

Neuroinflammation is a key pathological feature in neurological diseases, including Alzheimer's disease (AD). The nucleotide-binding domain leucine-rich repeat-containing proteins (NLRs) belong to the pattern recognition receptors (PRRs) family that sense stress signals, which play an important role in inflammation. As a member of NLRs, the NACHT, LRR and PYD domains-containing protein 3 (NLRP3) is predominantly expressed in microglia, the principal innate immune cells in the central nervous system (CNS). Microglia release proinflammatory cytokines to cause pyroptosis through activating NLRP3 inflammasome. The active NLRP3 inflammasome is involved in a variety of neurodegenerative diseases (NDs). Recent studies also indicate the key role of neuronal NLRP3 in the pathogenesis of neurological disorders. In this article, we reviewed the mechanisms of NLRP3 expression and activation and discussed the role of active NLRP3 inflammasome in the pathogenesis of NDs, particularly focusing on AD. The studies suggest that targeting NLRP3 inflammasome could be a novel approach for the disease modification.

Scoping Review of Randomized Trials With Discontinuation of Medicines in Older Adults

OBJECTIVES

To map the randomized trial evidence describing the feasibility of discontinuing active medications with potential adverse effects in older patients.

DESIGN

Scoping review with systematic search of PubMed, Embase, and Cochrane Library.

SETTING AND PARTICIPANTS

Randomized trials investigating discontinuation of a single medicine or medicine class in patients with mean age ≥65 years.

METHODS

We extracted trial characteristics including study design and assessed bias. As proxies for the "feasibility of discontinuation," we extracted the "dropout rate" and "disease recurrence rate."

RESULTS

We identified 40 trials investigating discontinuation of symptomatic (n = 26), preventive (n = 6), or both preventive and symptomatic medicines (n = 8) against psychiatric (n = 10), neurologic (n = 9), musculoskeletal (n = 8), cardiovascular (n = 5), respiratory (n = 4), and urologic diseases (n = 4). Five discontinuation designs were used, 75% (30/40) of trials were placebo-controlled, and 48% (19/40) of trials had bias disfavoring discontinuation. The dropout rate was similar between the discontinuation group and the continuation group in 79% of the trials (30/38), whereas disease recurrence was similar in 72% (23/32) of the trials. In 42% (13/31) of trials reporting both dropout rate and disease recurrence rate, the differences between groups were statistically insignificant and less than 10%; these trials investigated discontinuation of cholinesterase inhibitors for Alzheimer's disease in various settings (n = 3), alendronate for osteoporosis (n = 3), glucosamine for osteoarthritis, lithium as adjunct for unipolar depression, statins for cardiovascular disease in patients with limited life expectancy, droxidopa for neurogenic orthostatic hypotension, tamsulosin for lower urinary tract symptoms, sertraline for major depressive episode, and fentanyl patch for low back or osteoarthritis pain.

CONCLUSIONS AND IMPLICATIONS

We identified 40 randomized trials using a variety of designs investigating discontinuation of both symptomatic and preventive medicines in older patients. Discontinuation of medicines seems feasible for most of the investigated medicines. This scoping review can guide clinical practice and future trials on deprescribing.

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.

The synapse as a treatment avenue for Alzheimer's Disease

Alzheimer's disease (AD) is a neurodegenerative disorder with devastating symptoms, including memory impairments and cognitive deficits. Hallmarks of AD pathology are amyloid-beta (Aβ) deposition forming neuritic plaques and neurofibrillary tangles (NFTs). For many years, AD drug development has mainly focused on directly targeting the Aβ aggregation or the formation of tau tangles, but this disease has no cure so far. Other common characteristics of AD are synaptic abnormalities and dysfunctions such as synaptic damage, synaptic loss, and structural changes in the synapse. Those anomalies happen in the early stages of the disease before behavioural symptoms have occurred. Therefore, better understanding the mechanisms underlying the synaptic dysfunction found in AD and targeting the synapse, especially using early treatment windows, can lead to finding novel and more effective treatments that could improve the lives of AD patients. Researchers have recently started developing different disease-modifying treatments targeting the synapse to rescue and prevent synaptic dysfunction in AD. The main objectives of these new strategies are to halt synaptic loss, strengthen synaptic connections, and improve synaptic density, potentially leading to the rescue or prevention of cognitive impairments. This article aims to address the mechanisms of synaptic degeneration in AD and discuss current strategies that focus on the synapse for AD therapy. Alzheimer's disease (AD) is a neurodegenerative disorder that significantly impairs memory and causes cognitive and behavioural deficits. Scientists worldwide have tried to find a treatment that can reverse or rescue AD symptoms, but there is no cure so far. One prominent characteristic of AD is the brain atrophy caused by significant synaptic loss and overall neuronal damage, which starts at the early stages of the disease before other AD hallmarks such as neuritic plaques and NFTs. The present review addresses the underlying mechanisms behind synaptic loss and dysfunction in AD and discusses potential strategies that target the synapse.

Withdrawal or continuation of cholinesterase inhibitors or memantine or both, in people with dementia

BACKGROUND

Dementia is a progressive syndrome characterised by deterioration in memory, thinking and behaviour, and by impaired ability to perform daily activities. Two classes of drug - cholinesterase inhibitors (donepezil, galantamine and rivastigmine) and memantine - are widely licensed for dementia due to Alzheimer's disease, and rivastigmine is also licensed for Parkinson's disease dementia. These drugs are prescribed to alleviate symptoms and delay disease progression in these and sometimes in other forms of dementia. There are uncertainties about the benefits and adverse effects of these drugs in the long term and in severe dementia, about effects of withdrawal, and about the most appropriate time to discontinue treatment.

OBJECTIVES

To evaluate the effects of withdrawal or continuation of cholinesterase inhibitors or memantine, or both, in people with dementia on: cognitive, neuropsychiatric and functional outcomes, rates of institutionalisation, adverse events, dropout from trials, mortality, quality of life and carer-related outcomes.

SEARCH METHODS

We searched the Cochrane Dementia and Cognitive Improvement Group's Specialised Register up to 17 October 2020 using terms appropriate for the retrieval of studies of cholinesterase inhibitors or memantine. The Specialised Register contains records of clinical trials identified from monthly searches of a number of major healthcare databases, numerous trial registries and grey literature sources.

SELECTION CRITERIA

We included all randomised, controlled clinical trials (RCTs) which compared withdrawal of cholinesterase inhibitors or memantine, or both, with continuation of the same drug or drugs.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed citations and full-text articles for inclusion, extracted data from included trials and assessed risk of bias using the Cochrane risk of bias tool. Where trials were sufficiently similar, we pooled data for outcomes in the short term (up to 2 months after randomisation), medium term (3-11 months) and long term (12 months or more). We assessed the overall certainty of the evidence for each outcome using GRADE methods.

MAIN RESULTS

We included six trials investigating cholinesterase inhibitor withdrawal, and one trial investigating withdrawal of either donepezil or memantine. No trials assessed withdrawal of memantine only. Drugs were withdrawn abruptly in five trials and stepwise in two trials. All participants had dementia due to Alzheimer's disease, with severities ranging from mild to very severe, and were taking cholinesterase inhibitors without known adverse effects at baseline. The included trials randomised 759 participants to treatment groups relevant to this review. Study duration ranged from 6 weeks to 12 months. There were too few included studies to allow planned subgroup analyses. We considered some studies to be at unclear or high risk of selection, performance, detection, attrition or reporting bias. Compared to continuing cholinesterase inhibitors, discontinuing treatment may be associated with worse cognitive function in the short term (standardised mean difference (SMD) -0.42, 95% confidence interval (CI) -0.64 to -0.21; 4 studies; low certainty), but the effect in the medium term is very uncertain (SMD -0.40, 95% CI -0.87 to 0.07; 3 studies; very low certainty). In a sensitivity analysis omitting data from a study which only included participants who had shown a relatively poor prior response to donepezil, inconsistency was reduced and we found that cognitive function may be worse in the discontinuation group in the medium term (SMD -0.62; 95% CI -0.94 to -0.31). Data from one longer-term study suggest that discontinuing a cholinesterase inhibitor is probably associated with worse cognitive function at 12 months (mean difference (MD) -2.09 Standardised Mini-Mental State Examination (SMMSE) points, 95% CI -3.43 to -0.75; moderate certainty). Discontinuation may make little or no difference to functional status in the short term (SMD -0.25, 95% CI -0.54 to 0.04; 2 studies; low certainty), and its effect in the medium term is uncertain (SMD -0.38, 95% CI -0.74 to -0.01; 2 studies; very low certainty). After 12 months, discontinuing a cholinesterase inhibitor probably results in greater functional impairment than continuing treatment (MD -3.38 Bristol Activities of Daily Living Scale (BADLS) points, 95% CI -6.67 to -0.10; one study; moderate certainty). Discontinuation may be associated with a worsening of neuropsychiatric symptoms over the short term and medium term, although we cannot exclude a minimal effect (SMD - 0.48, 95% CI -0.82 to -0.13; 2 studies; low certainty; and SMD -0.27, 95% CI -0.47 to -0.08; 3 studies; low certainty, respectively). Data from one study suggest that discontinuing a cholinesterase inhibitor may result in little to no change in neuropsychiatric status at 12 months (MD -0.87 Neuropsychiatric Inventory (NPI) points; 95% CI -8.42 to 6.68; moderate certainty). We found no clear evidence of an effect of discontinuation on dropout due to lack of medication efficacy or deterioration in overall medical condition (odds ratio (OR) 1.53, 95% CI 0.84 to 2.76; 4 studies; low certainty), on number of adverse events (OR 0.85, 95% CI 0.57 to 1.27; 4 studies; low certainty) or serious adverse events (OR 0.80, 95% CI 0.46 to 1.39; 4 studies; low certainty), and on mortality (OR 0.75, 95% CI 0.36 to 1.55; 5 studies; low certainty). Institutionalisation was reported in one trial, but it was not possible to extract data for the groups relevant to this review.

AUTHORS' CONCLUSIONS

This review suggests that discontinuing cholinesterase inhibitors may result in worse cognitive, neuropsychiatric and functional status than continuing treatment, although this is supported by limited evidence, almost all of low or very low certainty. As all participants had dementia due to Alzheimer's disease, our findings are not transferable to other dementia types. We were unable to determine whether the effects of discontinuing cholinesterase inhibitors differed with baseline dementia severity. There is currently no evidence to guide decisions about discontinuing memantine. There is a need for further well-designed RCTs, across a range of dementia severities and settings. We are aware of two ongoing registered trials. In making decisions about discontinuing these drugs, clinicians should exercise caution, considering the evidence from existing trials along with other factors important to patients and their carers.

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.

Nerve Growth Factor Pathobiology During the Progression of Alzheimer's Disease

The current review summarizes the pathobiology of nerve growth factor (NGF) and its cognate receptors during the progression of Alzheimer's disease (AD). Both transcript and protein data indicate that cholinotrophic neuronal dysfunction is related to an imbalance between TrkA-mediated survival signaling and the NGF precursor (proNGF)/p75NTR-mediated pro-apoptotic signaling, which may be related to alteration in the metabolism of NGF. Data indicate a spatiotemporal pattern of degeneration related to the evolution of tau pathology within cholinotrophic neuronal subgroups located within the nucleus basalis of Meynert (nbM). Despite these degenerative events the cholinotrophic system is capable of cellular resilience and/or plasticity during the prodromal and later stages of the disease. In addition to neurotrophin dysfunction, studies indicate alterations in epigenetically regulated proteins occur within cholinotrophic nbM neurons during the progression of AD, suggesting a mechanism that may underlie changes in transcript expression. Findings that increased cerebrospinal fluid levels of proNGF mark the onset of MCI and the transition to AD suggests that this proneurotrophin is a potential disease biomarker. Novel therapeutics to treat NGF dysfunction include NGF gene therapy and the development of small molecule agonists for the cognate prosurvival NGF receptor TrkA and antagonists against the pan-neurotrophin p75NTR death receptor for the treatment of AD.

The effect of anti-dementia drugs on Alzheimer disease-induced cognitive impairment: A network meta-analysis

BACKGROUND

Cognitive impairment is a principal manifestation of Alzheimer disease (AD). To provide a clinical reference for the treatment of AD, a network meta-analysis (NMA) was performed to evaluate the effects of different anti-dementia drugs on the cognitive impairment exhibited by patients with AD.

METHODS

Relevant randomized controlled trials are found through the Pubmed database, Web of Science, Clinical Trials, Embase, Cohranne library, Chinese National Knowledge Infrastructure database, CBM databases, and Wanfang among others. A total of 33 articles were collected, with the earliest document collected having been published in February 2017. The included reports were screened for quality of papers by using strict inclusion and exclusion criteria. All analyses were based on previously published studies reporting de-identified data; thus, no ethical approval or patient consent were required. The Mini-Mental State Examination scores informed the classification of the 33 articles into a mild subgroup, which featured 11 articles, and 12 drugs (besides a placebo); a moderate subgroup, which featured 17 articles and 15 drugs (besides a placebo); and a severe subgroup, which featured 5 articles and 3 drugs (besides a placebo).

RESULTS

While donepezil, galanthamine, and huperzine demonstrated the highest efficacy in the mild cognitive dysfunction subgroup (mean difference = 5.2, 2.5, and 2.4, respectively). Donepezil, huperzine A, and rivastigmine achieved the most significant effects in the moderate cognitive dysfunction subgroup (MD = 3.8, 2.9, and 3.0 respectively). In the severe subgroup, donepezil was demonstrably superior to memantine. Donepezil was thus found to effectively address cognitive impairment in patients with AD regardless of the degrees of cognitive decline.

CONCLUSIONS

Evaluation of the clinically common anti-dementia drugs using NMA affirmed the utility of cholinesterase inhibitors, especially donepezil, in alleviating cognitive dysfunction of patients with AD. This study may therefore help to inform the clinical selection of pharmacotherapeutic interventions addressing cognitive dysfunction in patients with AD.

Meta-Analysis of Randomized Controlled Trials on the Efficacy and Safety of Donepezil, Galantamine, Rivastigmine, and Memantine for the Treatment of Alzheimer's Disease

To study the impact of donepezil, rivastigmine, galantamine, and memantine on cognitive, functional, behavioral, global changes and adverse effects in patients with mild, moderate and severe Alzheimer’s disease (AD), we screened the literature published before September 2017 in the Pubmed, Embase, Cochrane library and Web of Science Electronic databases according to the inclusion criteria. Thirty-six studies were finally determined from 1560 preliminary screened articles. The AD Assessment Scale-cognitive Subscale (ADAS-cog), AD Cooperative Study-Activities of Daily Living (ADCS-ADL), Neuropsychiatric Inventory (NPI), and Clinician’s Interview-Based Impression of Change Plus Caregiver Input scale (CIBIC+) were used as valid endpoints. Of the 36 trials included, meta-analyses of these placebo-control trials showed that there were significant differences between the donepezil, rivastigmine and placebo groups using ADAS-cog, ADCS-ADL, and CIBIC+. Meta-analyses of these placebo-controlled trials showed that there were significant differences between the galantamine and placebo groups using ADAS-cog, ADCS-ADL, NPI, and CIBIC+. These observations suggest that memantine is beneficial for stabilizing or slowing the decline in ADAS-cog and ADCS-ADL₁₉ changes in AD patients. However, there was no significant effect according to the ADCS-ADL₂₃, NPI, and CIBIC+ tests, which indicated that memantine treatment has no significant effect on these cognitive aspects of AD patients. Different effects of donepezil, rivastigmine, galantamine, or memantine on AD were found in this study. According to the results, we conclude that galantamine is effective in treating all aspects of AD and is the first choice for the treatment of AD. However, due to limited data, we should consider additional data to obtain more stable results.

Alignment of European Regulatory and Health Technology Assessments: A Review of Licensed Products for Alzheimer's Disease

Aims: To facilitate regulatory learning, we evaluated similarities and differences in evidence requirements between regulatory and health technology assessment (HTA) bodies of Alzheimer's disease (AD) approved products. Methods: The European marketing authorisation application dossiers and European public assessment reports (EPARs) of the licensed AD drugs were screened to identify the phase III randomised controlled trials (RCTs) and outcomes used. We also screened the assessment reports of the National Institute of Health and Care Excellence (NICE, England) and the National Health Care Institute (ZiN, the Netherlands) to identify the studies and outcomes used in HTA assessments. Results: The application dossiers of donepezil, galantamine, rivastigmine, and memantine contained 16 phase III RCTs in total. These trials were also included in HTA assessments except that NICE excluded studies that were not published (n = 2) or trials that included patients with other types of dementia (n = 3). In the regulatory assessments the focus was on cognitive and global outcomes, and to some extent on function. In the HTA assessments of clinical effectiveness other domains were also covered including: function, behaviour and mood, and, occasionally, quality of life. In the economic analyses of NICE the domains cognition, function, and quality of life were included. Conclusion: There was a large overlap in inclusion of trials in regulatory and HTA assessments, although the focus on specific outcomes slightly differed. Understanding the methods and perceptions of both authorities can stimulate regulatory and HTA cross-talk and further alignment, and therefore more rapid patient access to new treatments.

Donepezil for dementia due to Alzheimer's disease

BACKGROUND

Alzheimer's disease is the most common cause of dementia in older people. One approach to symptomatic treatment of Alzheimer's disease is to enhance cholinergic neurotransmission in the brain by blocking the action of the enzyme responsible for the breakdown of the neurotransmitter acetylcholine. This can be done by a group of drugs known as cholinesterase inhibitors. Donepezil is a cholinesterase inhibitor.This review is an updated version of a review first published in 1998.

OBJECTIVES

To assess the clinical efficacy and safety of donepezil in people with mild, moderate or severe dementia due to Alzheimer's disease; to compare the efficacy and safety of different doses of donepezil; and to assess the effect of donepezil on healthcare resource use and costs.

SEARCH METHODS

We searched Cochrane Dementia and Cognitive Improvement's Specialized Register, MEDLINE, Embase, PsycINFO and a number of other sources on 20 May 2017 to ensure that the search was as comprehensive and up-to-date as possible. In addition, we contacted members of the Donepezil Study Group and Eisai Inc.

SELECTION CRITERIA

We included all double-blind, randomised controlled trials in which treatment with donepezil was administered to people with mild, moderate or severe dementia due to Alzheimer's disease for 12 weeks or more and its effects compared with those of placebo in a parallel group of patients, or where two different doses of donepezil were compared.

DATA COLLECTION AND ANALYSIS

One reviewer (JSB) extracted data on cognitive function, activities of daily living, behavioural symptoms, global clinical state, quality of life, adverse events, deaths and healthcare resource costs. Where appropriate and possible, we estimated pooled treatment effects. We used GRADE methods to assess the quality of the evidence for each outcome.

MAIN RESULTS

Thirty studies involving 8257 participants met the inclusion criteria of the review, of which 28 studies reported results in sufficient detail for the meta-analyses. Most studies were of six months' duration or less. Only one small trial lasted 52 weeks. The studies tested mainly donepezil capsules at a dose of 5 mg/day or 10 mg/day. Two studies tested a slow-release oral formulation that delivered 23 mg/day. Participants in 21 studies had mild to moderate disease, in five studies moderate to severe, and in four severe disease. Seventeen studies were industry funded or sponsored, four studies were funded independently of industry and for nine studies there was no information on source of funding.Our main analysis compared the safety and efficacy of donepezil 10 mg/day with placebo at 24 to 26 weeks of treatment. Thirteen studies contributed data from 3396 participants to this analysis. Eleven of these studies were multicentre studies. Seven studies recruited patients with mild to moderate Alzheimer's disease, two with moderate to severe, and four with severe Alzheimer's disease, with a mean age of about 75 years. Almost all evidence was of moderate quality, downgraded due to study limitations.After 26 weeks of treatment, donepezil compared with placebo was associated with better outcomes for cognitive function measured with the Alzheimer's Disease Assessment Scale-Cognitive (ADAS-Cog, range 0 to 70) (mean difference (MD) -2.67, 95% confidence interval (CI) -3.31 to -2.02, 1130 participants, 5 studies), the Mini-Mental State Examination (MMSE) score (MD 1.05, 95% CI 0.73 to 1.37, 1757 participants, 7 studies) and the Severe Impairment Battery (SIB, range 0 to 100) (MD 5.92, 95% CI 4.53 to 7.31, 1348 participants, 5 studies). Donepezil was also associated with better function measured with the Alzheimer's Disease Cooperative Study activities of daily living score for severe Alzheimer's disease (ADCS-ADL-sev) (MD 1.03, 95% CI 0.21 to 1.85, 733 participants, 3 studies). A higher proportion of participants treated with donepezil experienced improvement on the clinician-rated global impression of change scale (odds ratio (OR) 1.92, 95% CI 1.54 to 2.39, 1674 participants, 6 studies). There was no difference between donepezil and placebo for behavioural symptoms measured by the Neuropsychiatric Inventory (NPI) (MD -1.62, 95% CI -3.43 to 0.19, 1035 participants, 4 studies) or by the Behavioural Pathology in Alzheimer's Disease (BEHAVE-AD) scale (MD 0.4, 95% CI -1.28 to 2.08, 194 participants, 1 study). There was also no difference between donepezil and placebo for Quality of Life (QoL) (MD -2.79, 95% CI -8.15 to 2.56, 815 participants, 2 studies).Participants receiving donepezil were more likely to withdraw from the studies before the end of treatment (24% versus 20%, OR 1.25, 95% CI 1.05 to 1.50, 2846 participants, 12 studies) or to experience an adverse event during the studies (72% vs 65%, OR 1.59, 95% 1.31 to 1.95, 2500 participants, 10 studies).There was no evidence of a difference between donepezil and placebo for patient total healthcare resource utilisation.Three studies compared donepezil 10 mg/day to donepezil 5 mg/day over 26 weeks. The 5 mg dose was associated with slightly worse cognitive function on the ADAS-Cog, but not on the MMSE or SIB, with slightly better QoL and with fewer adverse events and withdrawals from treatment. Two studies compared donepezil 10 mg/day to donepezil 23 mg/day. There were no differences on efficacy outcomes, but fewer participants on 10 mg/day experienced adverse events or withdrew from treatment.

AUTHORS' CONCLUSIONS

There is moderate-quality evidence that people with mild, moderate or severe dementia due to Alzheimer's disease treated for periods of 12 or 24 weeks with donepezil experience small benefits in cognitive function, activities of daily living and clinician-rated global clinical state. There is some evidence that use of donepezil is neither more nor less expensive compared with placebo when assessing total healthcare resource costs. Benefits on 23 mg/day were no greater than on 10 mg/day, and benefits on the 10 mg/day dose were marginally larger than on the 5 mg/day dose, but the rates of withdrawal and of adverse events before end of treatment were higher the higher the dose.

Pharmacological interventions for apathy in Alzheimer's disease

BACKGROUND

Despite the high prevalence of apathy in Alzheimer's disease (AD), and its harmful effects, there are currently no therapies proven to treat this symptom. Recently, a number of pharmacological therapies have been investigated as potential treatments for apathy in AD.

OBJECTIVES

Objective 1: To assess the safety and efficacy of pharmacotherapies for the treatment of apathy in Alzheimer's disease (AD).Objective 2: To assess the effect on apathy of pharmacotherapies investigated for other primary outcomes in the treatment of AD.

SEARCH METHODS

We searched the Specialized Register of the Cochrane Dementia and Cognitive Improvement Group (ALOIS), MEDLINE, Embase, CINAHL, PsycINFO, LILACS, ClinicalTrials.gov and the World Health Organization (WHO) portal, ICTRP on 17 May 2017.

SELECTION CRITERIA

Eligible studies were double-blind, randomized, placebo-controlled trials (RCTs) investigating apathy as a primary or secondary outcome in people with AD.

DATA COLLECTION AND ANALYSIS

Three review authors extracted data. We assessed the risks of bias of included studies using Cochrane methods, and the overall quality of evidence for each outcome using GRADE methods. We calculated mean difference (MD), standardized mean difference (SMD) or risk ratio (RR) with 95% confidence intervals on an intention-to-treat basis for all relevant outcome measures.

MAIN RESULTS

We included 21 studies involving a total of 6384 participants in the quantitative analyses. Risk of bias is very low to moderate. All studies reported appropriate methods of randomization and blinding. Most studies reported appropriate methods of allocation concealment. Four studies, three with methylphenidate and one with modafinil, had a primary aim of improving apathy. In these studies, all participants had clinically significant apathy at baseline. Methylphenidate may improve apathy compared to placebo. This finding was present when apathy was assessed using the apathy evaluation scale (AES), which was used by all three studies investigating methylphenidate: MD -4.99, 95% CI -9.55 to -0.43, n = 145, 3 studies, low quality of evidence, but not when assessed with the neuropsychiatric inventory (NPI)-apathy subscale, which was used by two of the three studies investigating methylphenidate: MD -0.08, 95% CI -3.85 to 3.69, n = 85, 2 studies, low quality of evidence. As well as having potential benefits for apathy, methylphenidate probably also slightly improves cognition (MD 1.98, 95% CI 1.06 to 2.91, n = 145, 3 studies, moderate quality of evidence), and probably improves instrumental activities of daily living (MD 2.30, 95% CI 0.74 to 3.86, P = 0.004, n = 60, 1 study, moderate quality of evidence), compared to placebo. There may be no difference between methylphenidate and placebo in the risk of developing an adverse event: RR 1.28, 95% CI 0.67 to 2.42, n = 145, 3 studies, low quality of evidence. There was insufficient evidence from one very small study of modafinil to determine the effect of modafinil on apathy assessed with the FrSBe-apathy subscale: MD 0.27, 95% CI -3.51 to 4.05, n = 22, 1 study, low quality of evidence. In all other included studies, apathy was a secondary outcome and participants were not selected on the basis of clinically significant apathy at baseline. We considered the evidence on apathy from these studies to be indirect and associated with publication bias. There was low or very low quality of evidence on cholinesterase inhibitors (ChEIs) (six studies), ChEI discontinuation (one study), antipsychotics (two studies), antipsychotic discontinuation (one study), antidepressants (two studies), mibampator (one study), valproate (three studies) and semagacestat (one study).

AUTHORS' CONCLUSIONS

Methylphenidate may demonstrate a benefit for apathy and may have slight benefits for cognition and functional performance in people with AD, but this finding is associated with low-quality evidence. Our meta-analysis is limited by the small number of studies within each drug class, risk of bias, publication bias, imprecision and inconsistency between studies. Additional studies should be encouraged targeting people with AD with clinically significant apathy which investigate apathy as a primary outcome measure, and which have a longer duration and a larger sample size. This could increase the quality of evidence for methylphenidate, and may confirm whether or not it is an effective pharmacotherapy for apathy in AD.

A narrative review of the safety concerns of deprescribing in older adults and strategies to mitigate potential harms

INTRODUCTION

As with prescribing or continuing medications, deprescribing brings with it the potential for harm as well as benefit. Uncertainty and avoidance of harm has been reported as a barrier to deprescribing in practice and may contribute to continuation of inappropriate medications.

AREAS COVERED

This narrative review covers four main safety concerns/potential harms of deprescribing in older adults: adverse drug withdrawal events, return of medical condition(s), reversal of drug-drug interactions and damage to the doctor-patient relationship. These are discussed in relation to medications in general, with some examples of medication classes used to illustrate the potential safety concerns. The majority of these harms can be minimized or even prevented by using a patient-centered, structured deprescribing process with planning, tapering and close monitoring during, and after medication withdrawal.

EXPERT OPINION

More research is needed into the safety concerns of deprescribing, however, avenues exist during drug development and post-marketing surveillance to gain knowledge on this topic. Questions remain about when it is suitable to discontinue certain medications/medication classes and there is uncertainty about the harms and benefits of both medication continuation and discontinuation in complex older adults.

Reduced basal forebrain atrophy progression in a randomized Donepezil trial in prodromal Alzheimer's disease

Acetylcholinesterase inhibitors are approved drugs currently used for the treatment of Alzheimer's disease (AD) dementia. Basal forebrain cholinergic system (BFCS) atrophy is reported to precede both entorhinal cortex atrophy and memory impairment in AD, challenging the traditional model of the temporal sequence of topographical pathology associated with AD. We studied the effect of one-year Donepezil treatment on the rate of BFCS atrophy in prodromal AD patients using a double-blind, randomized, placebo-controlled trial of Donepezil (10 mg/day). Reduced annual BFCS rates of atrophy were found in the Donepezil group compared to the Placebo treated arm. Secondary analyses on BFCS subregions demonstrated the largest treatment effects in the Nucleus Basalis of Meynert (NbM) and the medial septum/diagonal band (Ch1/2). Donepezil administered at a prodromal stage of AD seems to substantially reduce the rate of atrophy of the BFCS nuclei with highest concentration of cholinergic neurons projecting to the cortex (NbM), hippocampus and entorhinal cortex (Ch1/2).

Pharmacological treatment of neuropsychiatric symptoms in Alzheimer's disease: a systematic review and meta-analysis

BACKGROUND

A wide variety of pharmacological agents are used in the management of neuropsychiatric symptoms, which are common in Alzheimer's disease (AD), but results from randomised controlled trials (RCTs) on the efficacy and safety of these agents are conflicting.

OBJECTIVES

To quantify the efficacy and safety of pharmacological treatment on neuropsychiatric symptoms in AD patients.

METHODS

Systematic review and meta-analysis of RCTs comparing pharmacological agents with placebo on Neuropsychiatric Inventory (NPI) and safety outcomes in AD patients with neuropsychiatric symptoms.

RESULTS

Cholinesterase inhibitors (ChEIs) and atypical antipsychotics improved NPI total scores (ChEIs: standardised mean difference (SMD) -0.12; 95% CI -0.23 to -0.02; atypical antipsychotics: SMD -0.21; 95% CI -0.29 to -0.12), but antidepressants (95% CI -0.35 to 0.37) and memantine (95% CI -0.27 to 0.03) did not. However, ChEIs and atypical antipsychotics increased risk of dropouts due to adverse events (ChEIs: risk ratio (RR) 1.64; 95% CI 1.12 to 2.42; atypical antipsychotics: RR 2.24; 95% CI 1.53 to 3.26) and on incidence of adverse events (ChEIs: RR 1.08; 95% CI 1.01 to 1.17; atypical antipsychotics: RR 1.17; 95% CI 1.05 to 1.31). For typical antipsychotics, no study was included.

CONCLUSIONS

ChEIs and atypical antipsychotics could improve neuropsychiatric symptoms in AD patients, but with bad safety outcomes.

Drug persistency of cholinesterase inhibitors for patients with dementia of Alzheimer type in Korea

This study examined 1-year persistency with cholinesterase inhibitors (ChEIs) for the treatment of elderly Alzheimer's dementia (AD) patients in Korea. Korean Health Insurance Review & Assessment Service database from January 2005 to June 2006 was used. Patients aged 65 or older with AD diagnosis who were first prescribed a ChEI were included. The 1-year persistence, persistency rate, and switching patterns during the follow-up period were identified. Mean time to drug discontinuation was analyzed, and persistency rates between different patient factors were compared. The 1-year persistency rate of newly treated 6,461 AD patients was 24.0%, while 50% of study patients discontinued treatment by 91 days from initiation. Persistency rates of female patients (22.8%), patients in rural areas (12.7%), and primary care (10.2%) were relatively low (p < 0.001). Persistency rate differed between age groups (p < 0.001). Overall proportion of switching was 6.6%. The 1-year persistency rate of ChEIs for AD patients in Korea did not reach those of previous researches in other countries. Patients less likely to remain on therapy should be especially monitored to optimize treatment persistence.

Beyond symptomatic therapy: a re-examination of acetylcholinesterase inhibitors in Alzheimer’s disease

Acetylcholinesterase inhibitors (AChEIs) are generally regarded as palliative treatments for Alzheimer's disease that slow the progression of dementia symptoms without altering Alzheimer's disease's underlying pathogenic mechanisms. This concept is based on inference rather than evidence, and has limited the scope and persistence of AChEI use in clinical practice. Recent preclinical studies demonstrate that AChEIs exhibit a number of biological effects in addition to cholinesterase inhibition. A broader understanding of the possible mechanisms of action of AChEIs in Alzheimer's disease could result in more effective use and assist in the development of new and improved therapies. The available evidence brings into question the prevailing view that AChEIs are exclusively symptomatic treatments and supports the use of these agents persistently throughout the course of Alzheimer's disease.

Use of functional imaging across clinical phases in CNS drug development

The use of novel brain biomarkers using nuclear magnetic resonance imaging holds potential of making central nervous system (CNS) drug development more efficient. By evaluating changes in brain function in the disease state or drug effects on brain function, the technology opens up the possibility of obtaining objective data on drug effects in the living awake brain. By providing objective data, imaging may improve the probability of success of identifying useful drugs to treat CNS diseases across all clinical phases (I-IV) of drug development. The evolution of functional imaging and the promise it holds to contribute to drug development will require the development of standards (including good imaging practice), but, if well integrated into drug development, functional imaging can define markers of CNS penetration, drug dosing and target engagement (even for drugs that are not amenable to positron emission tomography imaging) in phase I; differentiate objective measures of efficacy and side effects and responders vs non-responders in phase II, evaluate differences between placebo and drug in phase III trials and provide insights into disease modification in phase IV trials.

Recommended measures for the assessment of cognitive and physical performance in older patients with dementia: a systematic review

Aim/Goal

To recommend a set of neuropsychological and physical exercise tests for researchers to assess cognition and physical fitness in clinical trials with older patients with dementia; to create consensus, decrease heterogeneity, and improve research quality.

Methods

A literature search (2005–2011) yielded 89 randomized controlled trials. To provide information on test recommendations the frequency of test use, effect size of the test outcome, study quality, and psychometric properties of tests were analyzed.

Results

Fifty-nine neuropsychological tests (cognitive domains: global cognition, executive functioning, memory, and attention) and 10 exercise tests (physical domains: endurance capacity, muscle strength, balance, and mobility) were found.

Conclusion

The Severe Impairment Battery, Mini Mental State Examination, and Alzheimer Disease Assessment Scale – cognitive subscale were recommended to measure global cognition. The Verbal Fluency Test Category/Letters, Clock Drawing Test, and Trail Making Test-B were recommended to measure executive functioning. No specific memory test could be recommended. The Digit Span Forward, Digit Span Backward, and Trail Making Test-A were recommended to measure attention. As physical exercise tests, the Timed Up and Go and Six Meter Walk for mobility, the Six Minute Walk Distance for endurance capacity, and the Tinetti Balance Scale were recommended.

Are the effects of a non-drug multimodal activation therapy of dementia sustainable? Follow-up study 10 months after completion of a randomised controlled trial

BACKGROUND

Little is known about the long-term success of non-drug therapies for treating dementia, especially whether the effects are sustained after therapy ends. Here, we examined the effects of a one-year multimodal therapy 10 months after patients completed the therapy.

METHODS

This randomised, controlled, single-blind, longitudinal trial involved 61 patients (catamnesis: n = 52) with primary degenerative dementia in five nursing homes in Bavaria, Germany. The highly standardised intervention, MAKS, consisted of motor stimulation, practice of activities of daily living (ADLs), and cognitive stimulation. Each group of 10 patients was treated for 2 h, 6 days a week for 12 months. Control patients received standard nursing home care. At baseline, at the end of therapy (month 12), and 10 months thereafter (month 22), cognitive functioning was assessed using the cognitive subscale of the Alzheimer's Disease Assessment Scale, and the ability to perform ADLs was assessed using the Erlangen Test of Activities of Daily Living.

RESULTS

During the therapy phase, the MAKS patients maintained their cognitive function and ability to carry out ADLs. After the end of therapy, both the control and the MAKS groups deteriorated in both their cognitive function (control, p = 0.02; MAKS, p < 0.001) and their ability to carry out ADLs (control, p < 0.001; MAKS, p = 0.001). However, in a confound-adjusted multiple regression model, the ability of the MAKS group to perform ADLs remained significantly higher than that of the control group even 10 months after the end of therapy (H0: βMAKS + βMAKS month 22 = 0; χ2 = 3.8568, p = 0.0496). Cohen's d for the difference between the two groups in ADLs and cognitive abilities 10 months after the end of therapy was 0.40 and 0.22, respectively.

CONCLUSIONS

A multimodal non-drug therapy of dementia resulted in stabilisation of the ability to perform ADLs, even beyond the end of therapy. To prevent functional decline for as long as possible, therapy should be performed continuously until the benefit for the patient ends. Follow-up studies on larger numbers of patients are needed to definitively confirm these results.

TRIAL REGISTRATION

http://www.isrctn.com Identifier: ISRCTN87391496.

Two galantamine titration regimens in patients switched from donepezil

OBJECTIVES

In addition to inhibiting acetylcholinesterase, galantamine has allosteric-modulating activity at nicotinic receptors. This may make galantamine an attractive option for patients starting treatment for Alzheimer's disease (AD), but also for those who have not benefited from their current therapy. This study explored outcomes in subjects with AD transitioning from donepezil because of insufficient tolerability or efficacy.

MATERIALS AND METHODS

Subjects previously receiving donepezil for mild-to-moderate AD were enrolled in a 12-week randomized, open-label study. After screening and a 7-day washout, subjects were randomly allocated to galantamine fast (8 mg/week increments) or slow (8 mg/4 week) titration to 16-24 mg. Efficacy outcomes included the Alzheimer's Disease Assessment Scale - cognitive subscale (ADAS-cog/11), Mini-Mental State Examination (MMSE), Clinician's Interview-Based Impression of Change - Plus Caregiver's Input (CIBIC-plus) and Alzheimer's Disease Cooperative Study - Activities of Daily Living Inventory (ADCS-ADL).

RESULTS

Eighty-six of 89 patients (fast titration, n = 44; slow titration, n = 45) completed the study. At week 12, ADAS-cog/11 score improved from screening by 2.6 and 0.6 in the fast- and slow-titration arms, respectively (overall, -1.6; P = 0.002). MMSE scores improved slightly in both arms (overall, +0.9; P = 0.002). Two-thirds of patients had improvement or no change on the CIBIC-plus at week 12. ADCS-ADL scores did not change significantly from screening in either treatment arm. Galantamine was generally well tolerated; nausea (5.6%) and bradycardia (4.5%) were the most commonly reported adverse events.

CONCLUSIONS

Patients in whom donepezil is ineffective or poorly tolerated may benefit from a switch to galantamine.

A systematic review of adverse events in the placebo arm of donepezil trials: the role of cognitive impairment

BACKGROUND

In randomized clinical trials, adverse events (AEs) are reported for the drug under evaluation and compared with the placebo group. Patients who receive placebo treatment report a high frequency of AEs, but little is understood about the nature of these. No study has yet analyzed the level of cognitive impairment as a crucial aspect for the AEs reported by patients.

METHODS

The rates of AEs reported by patients with mild cognitive impairment (MCI) and Alzheimer's disease (AD) in the placebo arms of donepezil trials were compared using a systematic review approach. PubMed was searched with the terms "MCI and donepezil" as well as "AD and donepezil" from January 1989 to December 2010. Nineteen studies fulfilled the selection criteria (3 MCI, n = 783; 16 AD, n = 2,059).

RESULTS

An overall comparison of 81 categories of AEs in the placebo arm of MCI versus AD trials showed that patients in AD trials experienced a significantly higher number of AEs than patients in MCI trials (p < 0.001).

CONCLUSIONS

This is the first study showing that AD patients may be at a greater risk of developing AEs than MCI patients. This may be related to a greater presence of somatic comorbidity predisposing them to express emotional distress as physical symptoms and/or to AD patients being frailer and therefore more susceptible to AEs. The phenomena we observed may be interpreted in terms of the "nocebo effect".

Application of Choynowski's Memory Scale in assessment of patients with dementia

INTRODUCTION

Neuropsychological assessment of patients with dementia necessitates the use of varied memory tasks designed to measure different memory processes, including information memorization, retention and retrieval. A valid memory battery should be demonstrated to discriminate between demented and non-demented subjects and its scores should be related to the degree of intellectual impairment. The objective of this study was to evaluate the potential usefulness of Choynowski's Memory Scale in assessment of patients with dementia.

MATERIAL AND METHODS

Thirty-two patients with dementia and 64 age- and gender- matched healthy controls took part in the study. All participants were examined by means of Choynowski's Memory Scale, and the patients were additionally assessed by the Mini Mental State Examination and Clock Drawing Test (CDT).

RESULTS

All subtests of Choynowski's Memory Scale were found to highly significantly (p ≤ 0.001) discriminate between patients with dementia and healthy controls. Except for Digit Span, all other subtests of Choynowski's battery were highly correlated with the global mental status as assessed by MMSE with correlation coefficients ranging from 0.59 to 0.81. Most subtests of Choynowski's Memory Scale were also moderately or highly correlated with performance on the CDT, and the correlations coefficients between the total score on Memory Scale and the CDT were r = 0.66 and r = 0.61 (p ≤ 0.001) for the free recall drawing and copying, respectively.

CONCLUSIONS

Choynowski's Memory Scale showed high discriminative properties and strong associations with the degree of intellectual impairment in dementia. The results encourage the use of this battery in clinical settings.

Caprospinol: discovery of a steroid drug candidate to treat Alzheimer's disease based on 22R-hydroxycholesterol structure and properties

The overall ability of the brain to synthesise neuroactive steroids led us to the identification of compounds that would reproduce aspects of neurosteroid pharmacology. The rate-determining step in neurosteroid biosynthesis is the import of the substrate cholesterol into the mitochondria, where it is metabolised into pregnenolone via the intermediate 22R-hydroxycholesterol. The levels of translocator protein 18-kDa, mediating the import of cholesterol into mitochondria, correlated with increased pregnenolone formation and reduced levels of 22R-hydroxycholesterol in biopsies from Alzheimer's disease (AD), but not age-matched control, brains. 22R-hydroxycholesterol was shown to protect against β-amyloid (Aβ(42) )-induced neurotoxicity. In search of 22R-hydroxycholesterol stable analogues, we identified the naturally occurring heterospirostenol, (22R,25R)-20α-spirost-5-en-3β-yl hexanoate (caprospinol) and derivatives that protect neuronal cells against Aβ(1-42) neurotoxicity. The neuroprotective effect of caprospinol is the result of a combination of overlapping properties, including: (i) the ability to bind to Aβ(42) and reduce plaque formation in the brain in vivo; (ii) interaction with components of the mitochondria respiratory chain resulting in an anti-uncoupling effect; (iii) the capacity to scavenge Aβ(42) monomers present in mitochondria; and (iv) the property of being a sigma-1 receptor ligand. In vivo, caprospinol crosses the blood-brain barrier, accumulates in the brain, and restores cognitive impairment in a pharmacological rat model of AD. Caprospinol is stable, does not bind to known steroid receptors, is devoid of mutagenic and genotoxic properties, and is devoid of acute toxicity in rodents. The pharmacokinetics and pharmacodynamics of caprospinol were studied, and long-term toxicity studies are under investigation, aiming to develop this compound as a disease-modifying drug for the treatment of AD.

The efficacy of licensed-indication use of donepezil and memantine monotherapies for treating behavioural and psychological symptoms of dementia in patients with Alzheimer's disease: systematic review and meta-analysis

BACKGROUND/AIMS

Behavioural and psychological symptoms of dementia (BPSD) in Alzheimer's disease (AD) greatly increase caregiver burden. The abilities of donepezil and memantine to manage BPSD within their licensed indications in AD were compared.

METHODS

A systematic review, random effects meta-analysis and Bucher indirect comparison were conducted.

RESULTS

Six randomised controlled studies (4 donepezil and 2 memantine) reported use within the licensed indication and had Neuropsychiatric Inventory (NPI) data suitable for meta-analysis. BPSD showed significant improvement with donepezil compared with placebo [weighted mean difference (WMD) in NPI -3.51, 95% confidence interval (CI) -5.75, -1.27], whereas this was not the case for memantine (WMD -1.65, 95% CI -4.78, 1.49). WMD in NPI for donepezil versus memantine favoured donepezil but was not statistically significant (-1.86, 95% CI -5.71, 1.99; p = 0.34).

CONCLUSION

Within its licensed indication, donepezil is efficacious for the management of BPSD in AD compared with placebo.

Donepezil treatment in severe Alzheimer's disease: a pooled analysis of three clinical trials

OBJECTIVE

Individual clinical trials have demonstrated benefits of donepezil in patients with severe Alzheimer's disease (AD). Data were pooled from three randomized, placebo-controlled trials of donepezil for severe AD to further evaluate treatment effects and overall tolerability/safety.

METHODS

Total scores and sub-scores were analyzed for measures of cognition, global function, function, and behavior. Additional analyses were performed to investigate (1) relationships between cognitive, functional, and behavioral changes, and (2) patterns of combined domain response.

RESULTS

Using pooled total scores, significant treatment differences at endpoint in favor of donepezil were observed for cognition, global function (both p < 0.0001), and function (p = 0.03), with an effect size (Cohen's d) of 0.51, 0.26, and 0.17, respectively. There was no significant treatment difference for behavior. However, donepezil-treated patients with stabilized/improved cognition tended to show significant improvements in function and behavior over placebo-treated patients. Patients treated with donepezil were 2-3 times more likely to achieve a combined domain response than placebo-treated patients (p < 0.0001). Adverse events were as expected for cholinergic therapy, and mortality rates were similar between the treatment groups.

CONCLUSIONS

These findings suggest measurable donepezil-mediated symptomatic benefits in cognition, global function, and daily living activities in patients with severe AD. The treatment effects support the importance of cholinesterase inhibition as a clinically relevant therapeutic option across the spectrum of AD.

Is long-term treatment of Alzheimer's disease with cholinesterase inhibitor therapy justified?

The cholinesterase inhibitors (ChEIs) donepezil, rivastigmine and galantamine are the current mainstays in the drug treatment of Alzheimer's disease (AD). There is convincing evidence that these agents provide at least modest cognitive, behavioural and functional benefit for 6-12 months at all stages of the disease. Longer term benefits cannot be directly examined by placebo-controlled trials. Nevertheless, the results of virtually all open-label extensions of the pivotal trials, studies of patients with AD at different levels of severity and clinical trials using other designs favour treatment over no treatment for periods of up to 5 years. There are plausible biological reasons why ChEIs might be expected to work over a prolonged period of time although, to date, studies using various markers to chart the effects of medication on long-term disease progression have yielded mixed results. The most contentious issue regarding long-term treatment is economic, but the majority of available economic analyses suggest net savings over the long term if patients with AD receive persistent treatment with ChEIs.

Behavioral effects of current Alzheimer's disease treatments: a descriptive review

BACKGROUND

Behavioral abnormalities and neuropsychiatric symptoms are common manifestations of Alzheimer's disease (AD). Many clinical trials of cholinesterase inhibitors (ChE-Is) and memantine have included behavioral measures as primary or secondary outcomes, and most have observed behavioral benefits in conjunction with treatment. The purpose of this review was to determine the frequency of positive behavioral outcomes in AD clinical trials and clinical reports, to determine the symptoms most responsive to antidementia agents, and to explore factors that correlate with negative outcomes in clinical trials of antidementia agents with regard to behavioral measures.

METHODS

We performed a computerized search of randomized clinical trials and open-label studies of ChE-Is and memantine for AD including a behavioral outcome measure. Studies involving 10 or more patients using therapeutic doses of the target agents and including a behavioral measure as a primary or secondary outcome were included in this review.

RESULTS

One hundred fifty-seven peer-reviewed articles and 68 publicly presented abstracts were identified in the literature search. Subsequent review established that 15 publications arising from 13 randomized, double-blind, placebo-controlled AD trials met the review inclusion criteria. Positive outcomes on behavioral measures were reported in 8 of 15 publications as a primary or secondary outcome. In most blinded AD clinical trials, behavioral measures were secondary outcomes. Mood symptoms and apathy have most commonly responded to ChE-Is, whereas memantine has been associated with a reduction in irritability and agitation. However, there is substantial variability among trials in terms of behavioral outcomes. Studies that assessed patients with more severe dementia, included patients with less severe behavioral disturbances at baseline, involved institutionalized patients, or were international in scope tended to have negative outcomes. In institutionalized patients there is commonly an improvement in the placebo group that confounds the observation of any drug-placebo difference.

CONCLUSIONS

Antidementia agents have been associated with beneficial behavioral outcomes in many randomized clinical trials and open-label studies. Most studies are not designed to test the psychotropic properties of antidementia drugs. Trials with negative behavioral outcomes are most likely to involve patients who are institutionalized and have few behavioral disturbances at baseline. Clinical trials designed to assess behavioral effects of antidementia agents should anticipate these factors.

Donepezil: an update

Donepezil hydrochloride is the most widely prescribed drug for Alzheimer's disease (AD). The main mechanism of action through which it influences cognition and function is presumed to be the inhibition of acetylcholinesterase enzyme in the brain; however, donepezil may also impact the pathophysiology of AD at several other points. Officially approved for mild-to-moderate and severe AD, donepezil has also been shown to be effective in early-stage AD, vascular dementia, Parkinson's disease dementia/Lewy body disease and cognitive symptoms associated with multiple sclerosis. In addition, one study suggested that donepezil may delay the onset of AD in subjects with mild cognitive impairment, a prodrome to AD. The pharmacokinetics, pharmacodynamics, safety/tolerability profile and drug interaction properties of donepezil make it an easy and safe agent to use. However, in general, the efficacy of donepezil is limited, and ongoing studies are investigating other agents that may ultimately overtake its present position as the mainstay of anti-AD therapy.

Gerontology forum: an update on the literature

New treatments and treatment protocols for diseases affecting the elderly are evolving as we strive to meet the needs of an aging society. To help you keep up to date with the latest advances worldwide on all aspects of drug therapy and patient management, this section of the journal brings you information selected from the rapid drug news alerting service Inpharma Weekly. Each issue contains easy-to-read summaries of the most important research and development news, clinical studies, treatment guidelines, and pharmacoeconomic news.