Donepezil for dementia due to Alzheimer's disease

Drug Development for Alzheimer's and Parkinson's Disease: Where Do We Go Now?

Neurodegenerative diseases (NDs) are a set of progressive, chronic, and incurable diseases characterized by the gradual loss of neurons, culminating in the decline of cognitive and/or motor functions. Alzheimer's disease (AD) and Parkinson's disease (PD) are the most common NDs and represent an enormous burden both in terms of human suffering and economic cost. The available therapies for AD and PD only provide symptomatic and palliative relief for a limited period and are unable to modify the diseases' progression. Over the last decades, research efforts have been focused on developing new pharmacological treatments for these NDs. However, to date, no breakthrough treatment has been discovered. Hence, the development of disease-modifying drugs able to halt or reverse the progression of NDs remains an unmet clinical need. This review summarizes the major hallmarks of AD and PD and the drugs available for pharmacological treatment. It also sheds light on potential directions that can be pursued to develop new, disease-modifying drugs to treat AD and PD, describing as representative examples some advances in the development of drug candidates targeting oxidative stress and adenosine A2A receptors.

Investigation into the vascular contributors to dementia and the associated treatments

As the average lifespan has increased, memory disorders have become a more pressing public health concern. However, dementia in the elderly population is often neglected in light of other health priorities. Therefore, expanding the knowledge surrounding the pathology of dementia will allow more informed decision-making regarding treatment within elderly and older adult populations. An important emerging avenue in dementia research is understanding the vascular contributors to dementia. This review summarizes potential causes of vascular cognitive impairment like stroke, microinfarction, hypertension, atherosclerosis, blood-brain-barrier dysfunction, and cerebral amyloid angiopathy. Also, this review address treatments that target these vascular impairments that also show promising results in reducing patient's risk for and experience of dementia.

[Practical aspects of using donepezil in the treatment of dementia]

Donepezil is the most commonly used drug of the group of cholinesterase inhibitors. It is recommended for tretament of Alzheimer's disease. Donepezil is also used to treat dementia in Lewy body disease, Parkinson's disease with dementia, and vascular dementia. In Russia, donepezil is not used as often, which is facilitated by the concern of doctors about the possibility of serious side-effects. Clinical studies demonstrate the safety and good tolerability of donepezil. Our study included 62 patients with dementia due to various neurodegenerative diseases (Alzheimer's disease, Lewy body disease, Parkinson's disease with dementia). Thirty-seven patients (59.7%) started to receive donepezil. Side-effects, including bradycardia, hypertension, aggressive behavior, increased tremor, were observed in 7 patients (18.9%). There was no correlation between the development of side-effects and polymorphisms of the CYP2D6 and MDR1 genes.

Increased Noradrenaline as an Additional Cerebrospinal Fluid Biomarker in PSP-Like Parkinsonism

Academic centers utilize sequential clinical and neuroimaging assessments, including morphometric ratios, to obtain an unequivocal diagnosis of the non-synucleinopathic forms of Parkinsonism, such as progressive supranuclear palsy (PSP), however, a 1-2 year follow-up is required. The on-going long-lasting trials using anti-tau antibodies for PSP patients might therefore be biased by the incorrect enrollment of Parkinson's disease (PD) patients manifesting early axial signs. This perspective study aimed at achieving two major goals: first, to summarize the established biomarker candidates found in cerebrospinal fluid (CSF) in probable PSP patients, including low p-tau and altered neurofilaments. Second, we share our recent data, from CSF samples of well-selected PSP subjects, attributable to both main variants (and revisited in light of MDS criteria), who were followed for 1 year before and 2 years after lumbar puncture. We found a significantly high level of noradrenaline (NE) in these patients, similar to controls, when compared to PD patients. In contrast, CSF samples, in PD, showed a significant reduction in CSF NE and its major metabolite, which confirmed that PD is a multi-system disease involving several endogenous pathways. The NE axis impairments were prominent in PSP featuring worse NPI. It might represent a counterpart to the early and peculiar psycho-pathological profiles that are observed in tauopathies. In conclusion, we highlight that CSF biomarkers, which are easy to collect, can provide rapid insights as diagnostic tools. Early alterations in endogenous NE machinery in atypical Parkinsonism may represent a specific risk trait in forms characterized by a worse prognosis.

Cholinesterase Inhibitors for Alzheimer's Disease: Multitargeting Strategy Based on Anti-Alzheimer's Drugs Repositioning

In the brain, acetylcholine (ACh) is regarded as one of the major neurotransmitters. During the advancement of Alzheimer's disease (AD) cholinergic deficits occur and this can lead to extensive cognitive dysfunction and decline. Acetylcholinesterase (AChE) remains a highly feasible target for the symptomatic improvement of AD. Acetylcholinesterase (AChE) remains a highly viable target for the symptomatic improvement in AD because cholinergic deficit is a consistent and early finding in AD. The treatment approach of inhibiting peripheral AChE for myasthenia gravis had effectively proven that AChE inhibition was a reachable therapeutic target. Subsequently tacrine, donepezil, rivastigmine, and galantamine were developed and approved for the symptomatic treatment of AD. Since then, multiple cholinesterase inhibitors (ChEIs) have been continued to be developed. These include newer ChEIs, naturally derived ChEIs, hybrids, and synthetic analogues. In this paper, we summarize the different types of ChEIs which are under development and their respective mechanisms of actions.

Gantenerumab reduces amyloid-β plaques in patients with prodromal to moderate Alzheimer's disease: a PET substudy interim analysis

BACKGROUND

We previously investigated low doses (105 or 225 mg) of gantenerumab, a fully human monoclonal antibody that binds and removes aggregated amyloid-β by Fc receptor-mediated phagocytosis, in the SCarlet RoAD (SR) and Marguerite RoAD (MR) phase 3 trials. Several lines of evidence suggested that higher doses may be necessary to achieve clinical efficacy. We therefore designed a positron emission tomography (PET) substudy to evaluate the effect of gantenerumab uptitrated to 1200 mg every 4 weeks on amyloid-β plaques as measured using florbetapir PET in patients with prodromal to moderate Alzheimer's disease (AD).

METHODS

A subset of patients enrolled in the SR and MR studies who subsequently entered the open-label extensions (OLEs) were included in this substudy. Patients were aged 50 to 90 years with a clinical diagnosis of probable prodromal to moderate AD and were included based on a visual read of the original screening scan in the double-blind phase. Patients were assigned to 1 of 5 titration schedules (ranging from 2 to 10 months) with a target gantenerumab dose of 1200 mg every 4 weeks. The main endpoint of this substudy was change in amyloid-β plaque burden from OLE baseline to week 52 and week 104, assessed using florbetapir PET. Florbetapir global cortical signal was calculated using a prespecified standard uptake value ratio method converted to the Centiloid scale.

RESULTS

Sixty-seven of the 89 patients initially enrolled had ≥ 1 follow-up scan by August 15, 2018. Mean amyloid levels were reduced by 39 Centiloids by the first year and 59 Centiloids by year 2, a 3.5-times greater reduction than was seen after 2 years at 225 mg in SR. At years 1 and 2, 37% and 51% of patients, respectively, had amyloid-β plaque levels below the amyloid-β positivity threshold.

CONCLUSION

Results from this exploratory interim analysis of the PET substudy suggest that gantenerumab doses up to 1200 mg resulted in robust amyloid-β plaque removal at 2 years. PET amyloid levels were consistent with sparse-to-no neuritic amyloid-β plaques in 51% of patients after 2 years of therapy. Amyloid reductions were similar to those observed in other placebo-controlled studies that have suggested potential clinical benefit.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT01224106 (SCarlet RoAD) and NCT02051608 (Marguerite RoAD).

Targeting Inflammatory Pathways in Alzheimer's Disease: A Focus on Natural Products and Phytomedicines

Studies of the brains of Alzheimer's disease (AD) patients have revealed key neuropathological features, such as the deposition of aggregates of insoluble amyloid-β (Aβ) peptides and neurofibrillary tangles (NFTs). These pathological protein deposits, including Aβ peptides (which form senile plaques) and hyperphosphorylated tau (which aggregates into NFTs), have been assumed to be 'the cause of AD'. Aβ has been extensively targeted to develop an effective disease-modifying therapy, but with limited clinical success. Emerging therapies are also now targeting further pathological processes in AD, including neuroinflammation. This review focuses on the inflammatory and oxidative stress-related changes that occur in AD, and discusses some emerging anti-inflammatory natural products and phytomedicines. Many of the promising compounds are cytokine-suppressive anti-inflammatory drugs (CSAIDs), which target the proinflammatory AP1 and nuclear factor-κB signalling pathways and inhibit the expression of many proinflammatory cytokines, such as interleukin (IL)-1, IL-6, tumour necrosis factor-α, or nitric oxide produced by inducible nitric oxide synthase. However, many of these phytomedicines have not been tested in rigorous clinical trials in AD patients. It is not yet clear if the active compounds reach an effective concentration in the brain (due to limited bioavailability) or if they can slow down AD progression in long-term trials. The authors suggest that it is crucial for both the pharmacological and complementary medicine industries to conduct and fund those studies to significantly advance the field.

AD-8 for detection of dementia across a variety of healthcare settings

BACKGROUND

Dementia assessment often involves initial screening, using a brief tool, followed by more detailed assessment where required. The AD-8 is a short questionnaire, completed by a suitable 'informant' who knows the person well. AD-8 is designed to assess change in functional performance secondary to cognitive change.

OBJECTIVES

To determine the diagnostic accuracy of the informant-based AD-8 questionnaire, in detection of all-cause (undifferentiated) dementia in adults. Where data were available, we described the following: the diagnostic accuracy of the AD-8 at various predefined threshold scores; the diagnostic accuracy of the AD-8 for each healthcare setting and the effects of heterogeneity on the reported diagnostic accuracy of the AD-8.

SEARCH METHODS

We searched the following sources on 27 May 2014, with an update to 7 June 2018: ALOIS (Cochrane Dementia and Cognitive Improvement Group), MEDLINE (Ovid SP), Embase (Ovid SP), PsycINFO (Ovid SP), BIOSIS Previews (Thomson Reuters Web of Science), Web of Science Core Collection (includes Conference Proceedings Citation Index) (Thomson Reuters Web of Science), CINAHL (EBSCOhost) and LILACS (BIREME). We checked reference lists of relevant studies and reviews, used searches of known relevant studies in PubMed to track related articles, and contacted research groups conducting work on the AD-8 to try to find additional studies. We developed a sensitive search strategy and used standardised database subject headings as appropriate. Foreign language publications were translated.

SELECTION CRITERIA

We selected those studies which included the AD-8 to assess for the presence of dementia and where dementia diagnosis was confirmed with clinical assessment. We only included those studies where the AD-8 was used as an informant assessment. We made no exclusions in relation to healthcare setting, language of AD-8 or the AD-8 score used to define a 'test positive' case.

DATA COLLECTION AND ANALYSIS

We screened all titles generated by electronic database searches, and reviewed abstracts of potentially relevant studies. Two independent assessors checked full papers for eligibility and extracted data. We extracted data into two-by-two tables to allow calculation of accuracy metrics for individual studies. We then created summary estimates of sensitivity, specificity and likelihood ratios using the bivariate approach and plotting results in receiver operating characteristic (ROC) space. We determined quality assessment (risk of bias and applicability) using the QUADAS-2 tool.

MAIN RESULTS

From 36 papers describing AD-8 test accuracy, we included 10 papers. We utilised data from nine papers with 4045 individuals, 1107 of whom (27%) had a clinical diagnosis of dementia. Pooled analysis of seven studies, using an AD-8 informant cut-off score of two, indicated that sensitivity was 0.92 (95% confidence interval (CI) 0.86 to 0.96); specificity was 0.64 (95% CI 0.39 to 0.82); the positive likelihood ratio was 2.53 (95% CI 1.38 to 4.64); and the negative likelihood ratio was 0.12 (95% CI 0.07 to 0.21). Pooled analysis of five studies, using an AD-8 informant cut-off score of three, indicated that sensitivity was 0.91 (95% CI 0.80 to 0.96); specificity was 0.76 (95% CI 0.57 to 0.89); the positive likelihood ratio was 3.86 (95% CI 2.03 to 7.34); and the negative likelihood ratio was 0.12 (95% CI 0.06 to 0.24).Four studies were conducted in community settings; four were in secondary care (one in the acute hospital); and one study was in primary care. The AD-8 has a higher relative sensitivity (1.11, 95% CI 1.02 to 1.21), but lower relative specificity (0.51, 95% CI 0.23 to 1.09) in secondary care compared to community care settings.There was heterogeneity across the included studies. Dementia prevalence rate varied from 12% to 90% of included participants. The tool was also used in various different languages. Among all the included studies there was evidence of risk of bias. Issues included the selection of participants, conduct of index test, and flow of assessment procedures.

AUTHORS' CONCLUSIONS

The high sensitivity of the AD-8 suggests it can be used to identify adults who may benefit from further specialist assessment and diagnosis, but is not a diagnostic test in itself. This pattern of high sensitivity and lower specificity is often suited to a screening test. Test accuracy varies by setting, however data in primary care and acute hospital settings are limited. This review identified significant heterogeneity and risk of bias, which may affect the validity of its summary findings.

Muscarinic activity in hippocampus and entorhinal cortex is crucial for spatial and fear memory retrieval

BACKGROUND

Hippocampus and entorhinal cortex are key players of learning and memory. Despite their established role in memory processes, the contribution of muscarinic receptor activity in these brain regions during memory retrieval remains elusive. This study was aimed to assess the role of hippocampal CA1 and medial entorhinal cortex muscarinic receptors in memory retrieval.

METHOD

Mice were implanted with bilateral cannulas in the hippocampus CA1 and medial entorhinal cortex. After recovery they were trained for Morris water maze test, novel object recognition test and contextual fear conditioning. Scopolamine was infused 10 min prior to retrieval test.

RESULTS

Pre-test scopolamine infusion in hippocampal CA1 and medial entorhinal cortex significantly reduced overall exploration of objects (p<0.001). Similarly, pre-retrieval inactivation dorsal hippocampal CA1 and medial entorhinal cortex muscarinic activity caused significant impairment of spatial and fear memories retrieval (p<0.05).

CONCLUSION

These findings showed vital role of muscarinic activity in retrieving hippocampal and entorhinal cortex dependent memories and suggest a possible target for treating retrograde amnesia.

Identification of the optimal cognitive drugs among Alzheimer's disease: a Bayesian meta-analytic review

PURPOSE

The increasing prevalence of Alzheimer's disease (AD) demands more effective drugs, which are still unclear. The aim of this study is to compare the effectiveness of six drugs, such as donepezil, rivastigmine, galantamine, memantine, huperzine-A, and tacrine, in senior AD patients and identify the most effective one to improve patients' cognitive function.

METHODS

A system of search strategies was used to identify relevant studies including randomized controlled trials and clinical controlled trials evaluating the efficacy of six drugs in patients with AD. We updated relevant studies that were published before March 2018 as full-text articles. Using Bayesian network meta-analysis (NMA), we ranked cognitive ability objectively based on Mini-Mental State Examination (MMSE). Pairwise and NMAs were sequentially performed for the efficacy of drugs compared to each drug or control group through the trials included.

RESULTS

Among the 35 trials included, no obvious heterogeneity (I 2=0.0%, P=0.583) was revealed according to the pooled data for cognition in NMA and the mean difference (MD) of memantine (MD=1.7, 95% CI: 0.73, 2.8) showed that the memantine was significantly efficacious in the treatment group in terms of MMSE. Followed by galantamine, huperzine-A, rivastigmine, tacrine, and donepezil.

CONCLUSION

As the first NMA comparing the major drugs in market for AD, our study suggests that memantine might have a more significant benefit on cognition than other five drugs available.

Clinical Neurology and Epidemiology of the Major Neurodegenerative Diseases

Neurodegenerative diseases are a common cause of morbidity and cognitive impairment in older adults. Most clinicians who care for the elderly are not trained to diagnose these conditions, perhaps other than typical Alzheimer's disease (AD). Each of these disorders has varied epidemiology, clinical symptomatology, laboratory and neuroimaging features, neuropathology, and management. Thus, it is important that clinicians be able to differentiate and diagnose these conditions accurately. This review summarizes and highlights clinical aspects of several of the most commonly encountered neurodegenerative diseases, including AD, frontotemporal dementia (FTD) and its variants, progressive supranuclear palsy (PSP), corticobasal degeneration (CBD), Parkinson's disease (PD), dementia with Lewy bodies (DLB), multiple system atrophy (MSA), and Huntington's disease (HD). For each condition, we provide a brief overview of the epidemiology, defining clinical symptoms and diagnostic criteria, relevant imaging and laboratory features, genetics, pathology, treatments, and differential diagnosis.

Acetylcholinesterase inhibitors for treating dementia symptoms - a safety evaluation

INTRODUCTION

The prevalence of Alzheimer's disease (AD) continues to rise, while treatment options for cognitive impairment are limited. Acetylcholinesterase inhibitors (AChEIs) aim to provide symptomatic benefit for cognitive decline, however these drugs are not without adverse events (AEs). The safety profile of each drug must be taken carefully into consideration before being prescribed, as new dosages and formulations have recently been approved. Areas covered: Donepezil, galantamine and rivastigmine are the three AChEIs approved for the treatment of varying stages of AD. Numerous clinical trials and post-marketing studies have evaluated the safety of these medications. This article will review the safety, efficacy and tolerability of these drugs in treating AD. Topics including pharmacovigilance databases, concomitant drug interactions, prescribing cascades, and treatment discontinuation are also covered. Expert opinion: AChEI use in those with mild, moderate or severe AD provide modest improvements in cognition, function and behavior. The pharmacological treatment of AD using AChEIs is associated with generally mild AEs. Differences in drug formulations should be taken into account when determining the most appropriate route of administration for each individual. Furthermore, discontinuation of AChEIs must be carefully monitored as it may be associated with worsening cognitive impairment.

Development of a neuroprotective potential algorithm for medicinal plants

Medicinal plants are promising candidates for Alzheimer's disease (AD) research but there is lack of systematic algorithms and procedures to guide their selection and evaluation. Herein, we developed a Neuroprotective Potential Algorithm (NPA) by evaluating twenty-three standardized and chemically characterized Ayurvedic medicinal plant extracts in a panel of bioassays targeting oxidative stress, carbonyl stress, protein glycation, amyloid beta (Aβ) fibrillation, acetylcholinesterase (AChE) inhibition, and neuroinflammation. The twenty-three herbal extracts were initially evaluated for: 1) total polyphenol content (Folin-Ciocalteu assay), 2) free radical scavenging capacity (DPPH assay), 3) ferric reducing antioxidant power (FRAP assay), 4) reactive carbonyl species scavenging capacity (methylglyoxal trapping assay), 5) anti-glycative effects (BSA-fructose, and BSA-methylglyoxal assays) and, 6) anti-Aβ fibrillation effects (thioflavin-T assay). Based on assigned index scores from the initial screening, twelve extracts with a cumulative NPA score ≥40 were selected for further evaluation for their: 1) inhibitory effects on AChE activity, 2) in vitro anti-inflammatory effects on murine BV-2 microglial cells (Griess assay measuring levels of lipopolysaccharide-induced nitric oxide species), and 3) in vivo neuroprotective effects on Caenorhabditis elegans post induction of Aβ_1-42 induced neurotoxicity and paralysis. Among these, four extracts had a cumulative NPA score ≥60 including Phyllanthus emblica (amla; Indian gooseberry), Mucuna pruriens (velvet bean), Punica granatum (pomegranate) and Curcuma longa (turmeric; curcumin). These extracts also showed protective effects on H₂O₂ induced cytotoxicity in differentiated cholinergic human neuronal SH-SY5Y and murine BV-2 microglial cells and reduced tau protein levels in the SH-SY5Y neuronal cells. While published animal data support the neuroprotective effects of several of these Ayurvedic medicinal plant extracts, some remain unexplored for their anti-AD potential. Therefore, the NPA may be utilized, in part, as a strategy to help guide the selection of promising medicinal plant candidates for future AD-based research using animal models.

Drug treatments in Alzheimer's disease

Despite the significant public health issue that it poses, only five medical treatments have been approved for Alzheimer's disease (AD) and these act to control symptoms rather than alter the course of the disease. Studies of potential disease-modifying therapy have generally been undertaken in patients with clinically detectable disease, yet evidence suggests that the pathological changes associated with AD begin several years before this. It is possible that pharmacological therapy may be beneficial in this pre-clinical stage before the neurodegenerative process is established. Techniques providing earlier diagnosis, such as cerebrospinal fluid biomarkers and amyloid positron emission tomography neuroimaging, are key to testing this theory in clinical trials. Recent results from trials of agents such as aducanumab are encouraging but must also be interpreted with caution. Such medicines could potentially delay the onset of dementia and would therefore markedly reduce its prevalence. However, we currently remain a good distance away from clinically available disease-modifying therapy.

Current Treatment Options for Alzheimer's Disease and Parkinson's Disease Dementia

Alzheimer's disease (AD) and Parkinson's disease (PD) are the two most common neurodegenerative disorders encountered in clinical practice. Whilst dementia has long been synonymous with AD, it is becoming more widely accepted as part of the clinical spectrum in PD (PDD). Neuropsychiatric complications, including psychosis, mood and anxiety disorders, and sleep disorders also frequently co-exist with cognitive dysfunctions in AD and PDD patients. The incidence of such symptoms is often a significant source of disability, and may aggravate pre-existing cognitive deficits. Management of AD and PDD involves both pharmacological and non-pharmacological measures. Although research on pharmacological therapies for AD and PDD has so far had some success in terms of developing symptomatic treatments, the benefits are often marginal and non-sustained. These shortcomings have led to the investigation of non-pharmacological and novel treatments for both AD and PD. Furthermore, in light of the diverse constellation of other neuropsychiatric, physical, and behavioural symptoms that often occur in AD and PD, consideration needs to be given to the potential side effects of pharmacological treatments where improving one symptom may lead to the worsening of another, rendering the clinical management of these patients challenging. Therefore, the present article will critically review the evidence for both pharmacological and non-pharmacological treatments for cognitive impairment in AD and PD patients. Treatment options for other concomitant neuropsychiatric and behavioural symptoms, as well as novel treatment strategies will also be discussed.

Cerebrolysin in mild-to-moderate Alzheimer's disease: a meta-analysis of randomized controlled clinical trials

OBJECTIVE

The aim of this study was to provide a systematic and quantitative summary of benefit and risk of Cerebrolysin in patients with mild-to-moderate Alzheimer's disease (AD) and to avoid major deficiencies of an earlier meta-analysis.

DESIGN

This is a meta-analysis of randomized double-blind placebo-controlled clinical trials.

DATA SOURCES

Trials were identified with the help of PubMed, the Cochrane Dementia Group database, the Center for Collaborative Neurosciences, and references from reviews; no language restrictions were applied.

STUDY SELECTION

All randomized double-blind placebo-controlled studies on 30 ml/day of Cerebrolysin in mild-to-moderate AD were included.

RESULTS

There were 6 eligible randomized controlled trials comparing Cerebrolysin with placebo. For all studies, either individual patient data and/or published data (aggregate data) were available. Analyses were based on the odds ratio (OR) for dichotomized global clinical change and for safety criteria, on the standardized mean difference (SMD) for pooling of cognitive function, and on the Mann-Whitney statistic (MW) for multivariate analysis of 'global benefit' (combined effect of global clinical change and cognitive function). Cerebrolysin was significantly more effective than placebo at 4 weeks regarding cognitive function (4 weeks: SMD -0.40 points; 95% CI -0.66 to -0.13; p = 0.0031; 6 months: SMD -0.37 points; 95% CI -0.90 to 0.16; p = 0.1710), at 4 weeks and 6 months regarding global clinical change (4 weeks: OR 3.32; 95% CI 1.20-9.21; p = 0.0212; 6 months: OR 4.98; 95% CI 1.37-18.13; p = 0.0150), and at 4 weeks and 6 months regarding 'global benefit' (combined efficacy criteria; 4 weeks: MW 0.57, 95% CI 0.53-0.61; p = 0.0006; 6 months: MW 0.57; 95% CI 0.53-0.61; p = 0.0010). The safety aspects of Cerebrolysin were comparable to placebo.

CONCLUSION

This meta-analysis provides evidence that Cerebrolysin has an overall beneficial effect and a favorable benefit-risk ratio in patients with mild-to-moderate AD. Cerebrolysin as a therapeutic agent should be considered by clinicians seeking treatment options for mild-to-moderate AD.

A study of donepezil in female breast cancer survivors with self-reported cognitive dysfunction 1 to 5 years following adjuvant chemotherapy

PURPOSE

Some breast cancer survivors report cognitive difficulties greater than 1 year after chemotherapy. Acetylcholinesterase inhibitors (AChEI) may improve cognitive impairment. We conducted a randomized, placebo-controlled, pilot study to assess the feasibility of using the AChEI, donepezil, to improve subjective and objective measures of cognitive function in breast cancer survivors.

METHODS

Women who received adjuvant chemotherapy 1-5 years prior with current cognitive dysfunction symptoms were randomized to 5 mg of donepezil/day vs placebo for 6 weeks and if tolerated 10 mg/day for 18 weeks for a total of 24 weeks. A battery of validated measures of attention, memory, language, visuomotor skills, processing speed, executive function, and motor dexterity and speed was administered at baseline and at 24 and 36 weeks. Subjective cognitive function, fatigue, sleep, mood, and health-related quality of life were evaluated at baseline and at 12, 24, and 36 weeks.

RESULTS

Sixty-two patients were enrolled, 76 % completed the study, self-reported compliance was 98 %, and toxicities were minimal. At the end of treatment, the donepezil group performed significantly better than the control group on two parameters of memory-the Hopkins Verbal Learning Test -Revised (HVLT-R) Total Recall (p = 0.033) and HVLT-R Discrimination (p = 0.036). There were no significant differences on other cognitive variables or in subjective cognitive function or quality of life.

CONCLUSION

Accrual to this feasibility trial was robust, retention was good, compliance was excellent, and toxicities were minimal.

IMPLICATIONS FOR CANCER SURVIVORS

Randomized clinical trials in breast cancer survivors to improve cognitive dysfunction are feasible. A phase III trial testing the efficacy of donepezil is warranted given these pilot results.

Effectiveness and Safety of MLC601 in the Treatment of Mild to Moderate Alzheimer's Disease: A Multicenter, Randomized Controlled Trial

BACKGROUND

MLC601 is a possible modulator of amyloid precursor protein processing, and in a clinical trial study MLC601 showed some effectiveness in cognitive function in Alzheimer's disease (AD) patients. We aimed to evaluate the effectiveness and safety of MLC601 in the treatment of mild to moderate AD as compared to 3 approved cholinesterase inhibitors (ChEIs) including donepezil, rivastigmine and galantamine.

METHODS

In a multicenter, nonblinded, randomized controlled trial, 264 volunteers with AD were randomly divided into 4 groups of 66; groups 1, 2, 3 and 4 received donepezil, rivastigmine, MLC601 and galantamine, respectively. Subjects underwent a clinical diagnostic interview and a cognitive/functional battery including the Mini-Mental State Examination (MMSE) and Alzheimer's Disease Assessment Scale - Cognitive subscale (ADAS-Cog). Patients were visited every 4 months, and the score of cognition was recorded by the neurologists.

RESULTS

There were no significant differences in age, sex, marital status and baseline score of cognition among the 4 groups. In total, 39 patients (14.7%) left the study. Trend of cognition changes based on the modifications over the time for MMSE and ADAS-cog scores did not differ significantly among groups (p = 0.92 for MMSE and p = 0.87 for ADAS-Cog).

CONCLUSION

MLC601 showed a promising safety profile and also efficacy compared to 3 FDA-approved ChEIs.

Differential expression of Homer1a in the hippocampus and cortex likely plays a role in radiation-induced brain injury

Fractionated partial or whole-brain irradiation is the primary treatment for metastatic brain tumors. Despite reducing tumor burden and increasing lifespan, progressive, irreversible cognitive impairment occurs in >50% of the patients who survive >6 months after fractionated whole-brain irradiation. The exact mechanism(s) responsible for this radiation-induced brain injury are unknown; however, preclinical studies suggest that radiation modulates the extracellular receptor kinase signaling pathway, which is associated with cognitive impairment in many neurological diseases. In the study reported here, we demonstrated that the extracellular receptor kinase transcriptionally-regulated early response gene, Homer1a, was up-regulated transiently in the hippocampus and down-regulated in the cortex of young adult male Fischer 344 X Brown Norway rats at 48 h after 40 Gy of fractionated whole-brain irradiation. Two months after fractionated whole-brain irradiation, these changes in Homer1a expression correlated with a down-regulation of the hippocampal glutamate receptor 1 and protein kinase Cγ, and an up-regulation of cortical glutamate receptor 1 and protein kinase Cγ. Two drugs that prevent radiation-induced cognitive impairment in rats, the angiotensin type-1 receptor blocker, L-158,809, and the angiotensin converting enzyme inhibitor, ramipril, reversed the fractionated whole-brain irradiation-induced Homer1a expression at 48 h in the hippocampus and cortex and restored glutamate receptor 1 and protein kinase Cγ to the levels in sham-irradiated controls at 2 months after fractionated whole-brain irradiation. These data indicate that Homer1a is, (1) a brain region specific regulator of radiation-induced brain injury, including cognitive impairment and (2) potentially a druggable target for preventing it.

Disease-modifying drugs in Alzheimer's disease

Alzheimer's disease (AD) is an age-dependent neurodegenerative disorder and the most common cause of dementia. The early stages of AD are characterized by short-term memory loss. Once the disease progresses, patients experience difficulties in sense of direction, oral communication, calculation, ability to learn, and cognitive thinking. The median duration of the disease is 10 years. The pathology is characterized by deposition of amyloid beta peptide (so-called senile plaques) and tau protein in the form of neurofibrillary tangles. Currently, two classes of drugs are licensed by the European Medicines Agency for the treatment of AD, ie, acetylcholinesterase inhibitors for mild to moderate AD, and memantine, an N-methyl-D-aspartate receptor antagonist, for moderate and severe AD. Treatment with acetylcholinesterase inhibitors or memantine aims at slowing progression and controlling symptoms, whereas drugs under development are intended to modify the pathologic steps leading to AD. Herein, we review the clinical features, pharmacologic properties, and cost-effectiveness of the available acetylcholinesterase inhibitors and memantine, and focus on disease-modifying drugs aiming to interfere with the amyloid beta peptide, including vaccination, passive immunization, and tau deposition.

Ethanolic Extract of the Seed of Zizyphus jujuba var. spinosa Ameliorates Cognitive Impairment Induced by Cholinergic Blockade in Mice

In the present study, we investigated the effect of ethanolic extract of the seed of Zizyphus jujuba var. spinosa (EEZS) on cholinergic blockade-induced memory impairment in mice. Male ICR mice were treated with EEZS. The behavioral tests were conducted using the passive avoidance, the Y-maze, and the Morris water maze tasks. EEZS (100 or 200 mg/kg, p.o.) significantly ameliorated the scopolamine-induced cognitive impairment in our present behavioral tasks without changes of locomotor activity. The ameliorating effect of EEZS on scopolamine-induced memory impairment was significantly reversed by a sub-effective dose of MK-801 (0.0125 mg/kg, s.c.). In addition, single administration of EEZS in normal naïve mouse enhanced latency time in the passive avoidance task. Western blot analysis was employed to confirm the mechanism of memory-ameliorating effect of EEZS. Administration of EEZS (200 mg/kg) increased the level of memory-related signaling molecules, including phosphorylation of extracellular signal-regulated kinase or cAMP response element-binding protein in the hippocampal region. Also, the time-dependent expression level of brain-derived neurotrophic factor by the administration of EEZS was markedly increased from 3 to 9 h. These results suggest that EEZS has memory-ameliorating effect on scopolamine-induced cognitive impairment, which is mediated by the enhancement of the cholinergic neurotransmitter system, in part, via NMDA receptor signaling, and that EEZS would be useful agent against cognitive dysfunction such as Alzheimer’s disease.

Studies on interaction of buffalo brain cystatin with donepezil: an Alzheimer's drug

When drugs bind to a protein, the intramolecular structures can be altered, resulting in conformational change of the protein. Donepezil, an Acetyl Cholinesterase inhibitor (AChE), is commonly prescribed to patients with Alzheimer's disease (AD) to enhance cholinergic neurotransmission. It is the "first-line" agents in the treatment of Alzheimer's disease used to improve cognitive function in the disease. In the present study, a cysteine protease inhibitor (cystatin) has been isolated from buffalo brain using alkaline treatment, 40 to 60% ammonium sulphate fractionation and gel filtration chromatography on Sephadex G-75 with % yield of 64.13 and fold purification of 384.7. The purified inhibitor (Buffalo Brain Cystatin, (BBC)) was eluted as a single papain inhibitory peak which migrated as single band on native PAGE; however, on SDS-PAGE with and without beta mercaptoethanol ( β ME) BBC gave two bands of M W 31.6 and 12.4 KDa, respectively. The molecular weight determined by gel filtration came out to be 43.6 KDa. The UV spectra of cystatin on interaction with donepezil suggested a conformational change in the protein. The fluorescence spectra of BC-donepezil composite show structural changes indicating 40 nm red shift with significant increase in fluorescence intensity of cystatin in the presence of donepezil representing an unfolding of cystatin on interaction, which is an indication of side effect of donepezil during the use of this drug.

Treatment of Alzheimer's Disease: Current Management and Experimental Therapeutics

Alzheimer's disease (AD) is a major cause of morbidity in the elderly. AD affects aver 5 million persons in the United States, but because it increases in incidence in the elderly, and the "graying" population, AD is projected to increase in prevalence by many-fold over the coming decades. AD causes progressive mental impairment, resulting in the inability of persons to care for themselves. As a consequence, AD results in enormous costs to society due to both lost productivity, and required care. Thus, improved management and treatment is essential. In this review we will briefly review current understanding of the disease, including roles of beta-amyloid and tau proteins. We will then discuss current therapies in use, including the evidence for treatments with supplements, established drugs, and investigational therapeutic strategies, recently completed and ongoing.

Evaluating the cognitive effects of donepezil 23 mg/d in moderate and severe Alzheimer's disease: analysis of effects of baseline features on treatment response

Background

Treatment of Alzheimer’s disease with acetylcholinesterase inhibitors can result in symptomatic benefits, but patients often show variable responses. The objective of this post hoc analysis was to investigate relationships between easily identifiable baseline characteristics/demographics and cognitive response in patients treated with either donepezil 23 mg/d or 10 mg/d and to identify factors potentially influencing response.

Methods

A post hoc analysis was conducted using data from a large, 24-week, randomized, double-blind, international study enrolling patients with moderate to severe Alzheimer’s disease (baseline Mini-Mental State Examination [MMSE], 0-20) (NCT 00478205). Cognitive changes in subgroups of patients based on selected baseline and demographic characteristics were compared using the least squares mean changes in Severe Impairment Battery scores at Week 24. Univariate and multivariate analyses were also performed.

Results

Donepezil 23 mg/d provided statistically significant incremental cognitive benefits over donepezil 10 mg/d irrespective of baseline functional severity, measured by scores on the Alzheimer’s Disease Cooperative Study-Activities of Daily Living-severe version (P < 0.05). When patients were categorized by baseline cognitive severity (MMSE score), significant benefits of donepezil 23 mg/d over 10 mg/d were seen in both subgroups when based on MMSE scores of 0-9 versus 10-20 (P < 0.02 and P < 0.01, respectively), and in the more severe subgroup when based on MMSE scores of 0-16 versus 17-20 (P < 0.0001 and P > 0.05). Statistically significant incremental cognitive benefits of donepezil 23 mg/d over 10 mg/d were also observed regardless of age, gender, weight, or prestudy donepezil 10 mg/d treatment duration (P < 0.05). In the multivariate analysis, the only significant interaction was between treatment and baseline MMSE score.

Conclusions

The cognitive benefits of donepezil 23 mg/d over 10 mg/d were achieved regardless of the patient’s age, gender, weight, duration of prior donepezil 10 mg/d, and functional severity. The influence of baseline cognitive severity on response seemed to be dependent on the level of impairment, with cognitive benefits of donepezil 23 mg/d over 10 mg/d most apparent in those patients at a more advanced stage of disease. These data may be useful in helping practicing physicians make informed decisions for their patients with advanced Alzheimer’s disease.

Racial and ethnic disparities in Alzheimer's disease pharmacotherapy exposure: an analysis across four state Medicaid populations

BACKGROUND

Treatment disparities in Alzheimer's disease (AD) have received little attention. Determining whether disparities exist in this subpopulation is an important health policy issue.

OBJECTIVE

The aim was to determine whether an association existed between race/ethnicity and exposure to AD pharmacotherapy across 4 state Medicaid populations.

METHODS

Data from the Centers for Medicare and Medicaid Services (CMS) were used in this retrospective study. Persons with AD enrolled in California, Florida, New Jersey, or New York Medicaid programs on January 1, 2004, and remained in that program for 1 year. Individuals had an AD diagnosis based on the ICD-9-CM code 331.0. Outcomes of interest were exposure to a cholinesterase inhibitor (ChEI) or memantine. Multivariate logistic regression was used to test for the association between race/ethnicity and exposure to a ChEI or memantine. Variables of interest included demographic characteristics and resource utilization factors. The Oaxaca-Blinder decomposition method was used to test for disparities to determine whether exposure to AD pharmacotherapy was influenced by race.

RESULTS

Race, age, long-term care admittance, inpatient care admittance, state of residence, and sex were significant predictors of AD pharmacotherapy exposure (P < 0.0001 for all variables). Racial/ethnic disparities were observed with respect to exposure to a ChEI or memantine between non-Hispanic whites and Hispanics (in favor of Hispanics) in Florida (P < 0.0001), between non-Hispanic blacks and Hispanics (in favor of Hispanics) in California (P < 0.0001) and Florida (P < 0.0001), between non-Hispanic blacks and non-Hispanic others (in favor of non-Hispanic others) in California (P < 0.0001) and New York (P < 0.0001), and between Hispanics and non-Hispanic others (in favor of non-Hispanic others) in California (P = 0.001) and New York (P < 0.0001).

CONCLUSIONS

Disparities in AD pharmacotherapy exposure among minority populations are just as prevalent, if not of greater magnitude, than minority/white disparities.

Systematic review of the effectiveness of pharmacologic interventions to improve quality of life and well-being in people with dementia

OBJECTIVE

To review systematically, for the first time, the effectiveness of all pharmacologic interventions to improve quality of life and well-being in people with dementia.

DESIGN

Systematic review and meta-analysis.

METHODS

We systematically reviewed the 15 randomized controlled trials and one review that fitted predetermined criteria. We included studies that reported the outcomes quality of life, well-being, happiness, or pleasure.

MEASUREMENTS

We rated the validity of studies using a checklist. We calculated mean differences between intervention and control groups at follow-up.

RESULTS

None of the evaluated trials reported a significant benefit to quality of life or well-being for people with dementia when comparing those taking a drug or its comparator at follow-up (pooled weighted mean difference: 0.18 [95% confidence interval: -0.82 to 0.46]).

CONCLUSION

We found no consistent evidence that any drug improves quality of life in people with dementia. We recommend that all dementia trials should include quality of life as an outcome, as this is important to patients, and cannot be presumed from improvements in cognition or other symptomatic outcomes, especially if the latter are small.

Huperzine A for mild cognitive impairment

BACKGROUND

Mild cognitive impairment (MCI) has been proposed as a condition of intermediate symptomatology between the cognitive changes of ageing and fully developed symptoms of dementia. Treatment in the stages of MCI may delay the deterioration of cognitive impairment and delay the progression to dementia. Currently, the treatments for Alzheimer's disease have been focused on increasing acetylcholine levels in the brain. However, these drugs have not been proven to be effective for MCI and have numerous side effects. Huperzine A may have some beneficial effects in MCI.

OBJECTIVES

To assess the clinical efficacy and safety of huperzine A for the treatment of patients with MCI.

SEARCH METHODS

We searched ALOIS: the Cochrane Dementia and Cognitive Improvement Group's Specialized Register on 23 May 2011 using the terms: huperzine, ayapin, scoparon. ALOIS contains records of clinical trials identified from monthly searches of a number of major healthcare databases, numerous trial registries and grey literature sources. Additional searches were also performed separately in MEDLINE, EMBASE, PsycINFO, LILACS, clinicalTrials.gov, the ICTRP (WHO portal), CENTRAL (The Cochrane Library) and Web of Science with Conference Proceedings.The following Chinese databases were searched: The Chinese Biomedical Database, VIP Chinese Science and Technique Journals Database, China National Knowledge Infrastructure and The Chinese Clinical Trials Register. In addition, we handsearched 20 Chinese traditional medicine journals from between 1970 and 1989.

SELECTION CRITERIA

Randomised, parallel-group, placebo-controlled trials comparing huperzine A with placebo in patients with MCI were eligible for inclusion.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed studies for their eligibility for inclusion.

MAIN RESULTS

No eligible trials were identified. In the absence of any suitable randomised placebo-controlled trials in this area, we were unable to perform a meta-analysis.

AUTHORS' CONCLUSIONS

The currently available evidence is insufficient to assess the potential for huperzine A in the treatment of MCI. Randomised double-blind placebo-controlled trials are needed.

Mechanisms generating dual-component nicotinic EPSCs in cortical interneurons

Activation of cortical nicotinic receptors by cholinergic axons from the basal forebrain (BF) significantly impacts cortical function, and the loss of nicotinic receptors is a hallmark of aging and neurodegenerative disease. We have previously shown that stimulation of BF axons generates a fast α7 and a slow non-α7 receptor-dependent response in cortical interneurons. However, the synaptic mechanisms that underlie this dual-component nicotinic response remain unclear. Here, we report that fast α7 receptor-mediated EPSCs in the mouse cortex are highly variable and insensitive to perturbations of acetylcholinesterase (AChE), while slow non-α7 receptor-mediated EPSCs are reliable and highly sensitive to AChE activity. Based on these data, we propose that the fast and slow nicotinic responses reflect differences in synaptic structure between cholinergic varicosities activating α7 and non-α7 classes of nicotinic receptors.

The effect of stimulation therapy and donepezil on cognitive function in Alzheimer's disease. A community based RCT with a two-by-two factorial design

Background

Progressive neurodegeneration in Alzheimer’s disease (AD) induces cognitive deterioration, and there is controversy regarding the optimal treatment strategy in early AD. Stimulation therapy, including physical exercise and cholinesterase inhibitors are both reported to postpone cognitive deterioration in separate studies. We aimed to study the effect of stimulation therapy and the additional effect of donepezil on cognitive function in early AD.

Method

Design: A two-by-two factorial trial comprising stimulation therapy for one year compared to standard care to which a randomized double-blinded placebo controlled trial with donepezil was added.

Setting: Nine rural municipalities in Northern Norway.

Participants: 187 participants 65 years and older with a recent diagnosis of mild or moderate AD were included in the study of which 146 completed a one-year follow-up. INTERVENTIONS: In five municipalities the participants received stimulation therapy whereas participants in four received standard care. All participants were randomised double-blindly to donepezil or placebo and tested with three different cognitive tests four times during the one-year study period.

Main outcome: Changes in MMSE sum score.

Secondary outcome: Changes in ADAS-Cog and Clock Drawing Test.

Results

MMSE scores remained unchanged amongst AD participants receiving stimulation therapy and those receiving standard care. The results were consistent for ADAS-Cog and Clock Drawing Test. No time trend differences were found during one-year follow-up between groups receiving stimulation therapy versus standard care or between donepezil versus placebo.

Conclusion

In rural AD patients non-pharmacological and pharmacological therapy did not improve outcome compared with standard care but all groups retained cognitive function during one year follow-up. Other studies are needed to confirm these results.

Trial registration

ClinicalTrials.gov (Identifier: NCT00443014). EudraCT database (no 2004-002613-37).

Increased hippocampal CA1 density of serotonergic terminals in a triple transgenic mouse model of Alzheimer's disease: an ultrastructural study

Alzheimer's disease (AD) is a neurodegenerative pathology that deteriorates mnesic functions and associated brain regions including the hippocampus. Serotonin (5-HT) has an important role in cognition. We recently demonstrated an increase in 5-HT transporter (SERT) fibre density in the hippocampal CA1 in an AD triple transgenic mouse model (3xTg-AD). Here, we analyse the ultrastructural localisation, distribution and numerical density (N_v) of hippocampal SERT axons (SERT-Ax) and terminals (SERT-Te) and their relationship with SERT fibre sprouting and altered synaptic N_v in 3xTg-AD compared with non-transgenic control mice. 3xTg-AD animals showed a significant increase in SERT-Te N_v in CA1 at both, 3 (95%) and 18 months of age (144%), being restricted to the CA1 stratum moleculare (S. Mol; 227% at 3 and 180% at 18 months). 3xTg-AD animals also exhibit reduced N_v of perforated axospinous synapses (PS) in CA1 S. Mol (56% at 3 and 52% at 18 months). No changes were observed in the N_v of symmetric and asymmetrical synapses or SERT-Ax. Our results suggest that concomitant SERT-Te N_v increase and PS reduction in 3xTg-AD mice may act as a compensatory mechanism maintaining synaptic efficacy as a response to the AD cognitive impairment.

Cholinergic modulation of working memory activity in primate prefrontal cortex

The prefrontal cortex, a cortical area essential for working memory and higher cognitive functions, is modulated by a number of neurotransmitter systems, including acetylcholine; however, the impact of cholinergic transmission on prefrontal activity is not well understood. We relied on systemic administration of a muscarinic receptor antagonist, scopolamine, to investigate the role of acetylcholine on primate prefrontal neuronal activity during execution of working memory tasks and recorded neuronal activity with chronic electrode arrays and single electrodes. Our results indicated a dose-dependent decrease in behavioral performance after scopolamine administration in all the working memory tasks we tested. The effect could not be accounted for by deficits in visual processing, eye movement responses, or attention, because the animals performed a visually guided saccade task virtually error free, and errors to distracting stimuli were not increased. Performance degradation under scopolamine was accompanied by decreased firing rate of the same cortical sites during the delay period of the task and decreased selectivity for the spatial location of the stimuli. These results demonstrate that muscarinic blockade impairs performance in working memory tasks and prefrontal activity mediating working memory.

Dimebolin in dementia

The treatment options for Alzheimer's type dementia are limited to the use of acetyl-cholinesterase inhibitors, along with memantine in some cases, and offer variable success in the treatment of cognitive impairment and to improve or stabilize activities of daily living, behavioral abnormalities, and impairment of global function. This review examines dimebolin, a nonselective antihistamine drug that has been used in Russia in the past for its antihistamine effect and has now generated considerable interest in the treatment of Alzheimer's type dementia, following results in the initial trials (Doody et al., 2008) and is currently under further evaluation. This article considers various theories proposed to explain its effect in the treatment of dementia. The results from further trials will help to clarify the future of dimebolin as a potential treatment for chronic neurodegenerative disorders that include dementia that affects 25 million people worldwide.

Beyond the cholinergic hypothesis: do current drugs work in Alzheimer's disease?

Alzheimer's disease (AD) is a neurodegenerative disease characterized by memory and cognitive loss, and represents the leading cause of dementia in elderly people. Besides the complex biochemical processes involved in the neuronal degeneration (formation of senile plaques containing Abeta peptides, and development of neurofibrillary tangles), other molecular and neurochemical alterations, like cholinergic deficit due to basal forebrain degeneration, also occur. Because acetylcholine has been demonstrated to be involved in cognitive processes, the idea to increase acetylcholine levels to restore cognitive deficits has gained interest (the so-called cholinergic hypothesis). This has led to the development of drugs able to prevent acetylcholine hydrolysis (acetylcholinesterase inhibitors). However, the analysis of clinical efficacy of these drugs in alleviating symptoms of dementia showed unsatisfactory results. Despite such critical opinions on the efficacy of these drugs, it should be said that acetylcholinesterase inhibitors, and for some aspects memantine also, improve memory and other cognitive functions throughout most of the duration of the disease. The pharmacological activity of these drugs suggests an effect beyond the mere increase of acetylcholine levels. These considerations are in agreement with the idea that cognitive decline is the result of a complex and not fully elucidated interplay among different neurotransmitters. The role of each of the neurotransmitters implicated has to be related to a cognitive process and as a consequence to its decline. The current review aims to highlight the positive role of cholinergic drugs in alleviating cognitive deficits during wake as well as sleep. Moreover, we suggest that future therapeutic approaches have to be developed to restore the complex interplay between acetylcholine and other neurotransmitters systems, such as dopamine, serotonin, noradrenaline, or glutamate, that are likely involved in the progressive deterioration of several cognitive functions such as attention, memory, and learning.

Novel regimens and delivery systems in the pharmacological treatment of Alzheimer's disease

The mainstay of current management of patients with Alzheimer's disease involves drugs that provide symptomatic therapy. Research approaches for future therapy of Alzheimer's disease are focusing on disease modifying and/or preventive approaches. Two classes of medications have been approved by the US FDA for the treatment of Alzheimer's disease: the cholinesterase inhibitors (tacrine, donepezil, rivastigmine, galantamine), mostly for mild to moderate Alzheimer's disease, and the noncompetitive NMDA receptor antagonist memantine for the moderate to severe stages of Alzheimer's disease. Management of comorbid medical problems can be more complex in patients with dementia than in those without dementia. Unfortunately, medication adherence in Alzheimer's disease is low and good adherence is essential for attempting to slow disease progression and improve or stabilize quality of life. Simplifying treatment regimens and providing more caregiver- and patient-friendly modes of administration that fit in better with daily routines can ease caregiver stress which, in turn, may have a favourable impact on the patient's condition. To overcome problems of medication adherence in the elderly, simple, user-friendly dosage regimens should be prescribed for all medications; thus the need for novel regimens and delivery systems in the pharmacological treatment of Alzheimer's disease, such as once-daily donepezil, memantine and galantamine, and transdermal rivastigmine.

Therapy for Alzheimer's Disease: How Effective are Current Treatments?

Available symptomatic therapies for the treatment of Alzheimer's disease (AD) have been based on known neurotransmitter dysfunctions associated with the illness. The second-generation cholinesterase inhibitors and the N-methyl D-aspartate receptor antagonist memantine have been widely prescribed and studied. Meta-analyses of these therapies were reviewed, focusing on effectiveness and tolerability. Although many of the meta-analyses demonstrate statistically significant improvements, some question if these benefits are sufficient to justify their current widespread and protracted use. This has spurred the development of new disease-modifying therapies that aim to have a greater impact on this debilitating illness.

Tense prescriptions? Alzheimer medications and the anthropology of uncertainty

This article discusses the two major groups of Alzheimer medications, which are hotly debated in the specialized literature because of their doubtful efficacy. Examining this issue under the rubric of an ;anthropology of uncertainty,' this article seeks to address the question: how do doctors prescribe medications given tensions created by uncertainty? A partial answer is drawn from research conducted in Brazil with local psychogeriatricians, which has documented a high degree of certainty regarding Alzheimer drugs and their benefits. I argue that one reason for this certainty is that ;efficacy' has become increasingly non-specific in Alzheimer's disease through the broadening of outcome measures in clinical trials. While such measures previously focused on cognitive symptoms, they now encompass concepts such as functionality, quality of life and activities of daily living. The certainty of the Brazilian psychogeriatricians is further buttressed by three interacting elements: (i) the influence of the pharmaceutical industry; (ii) long-standing arguments for including non-cognitive symptoms in dementia care and research; and (iii) a specific discourse found in geriatrics and gerontology, which recognizes ;the person beyond cognition.'

Evidence-based ethics--what it should be and what it shouldn't

BACKGROUND

The concept of evidence-based medicine has strongly influenced the appraisal and application of empirical information in health care decision-making. One principal characteristic of this concept is the distinction between "evidence" in the sense of high-quality empirical information on the one hand and rather low-quality empirical information on the other hand. In the last 5 to 10 years an increasing number of articles published in international journals have made use of the term "evidence-based ethics", making a systematic analysis and explication of the term and its applicability in ethics important.

DISCUSSION

In this article four descriptive and two normative characteristics of the general concept "evidence-based" are presented and explained systematically. These characteristics are to then serve as a framework for assessing the methodological and practical challenges of evidence-based ethics as a developing methodology. The superiority of evidence in contrast to other empirical information has several normative implications such as the legitimization of decisions in medicine and ethics. This implicit normativity poses ethical concerns if there is no formal consent on which sort of empirical information deserves the label "evidence" and which does not. In empirical ethics, which relies primarily on interview research and other methods from the social sciences, we still lack gold standards for assessing the quality of study designs and appraising their findings.

CONCLUSION

The use of the term "evidence-based ethics" should be discouraged, unless there is enough consensus on how to differentiate between high- and low-quality information produced by empirical ethics. In the meantime, whenever empirical information plays a role, the process of ethical decision-making should make use of systematic reviews of empirical studies that involve a critical appraisal and comparative discussion of data.

Prolonged cholinergic enrichment influences regional cortical activation in early Alzheimer's disease

Neuroimaging studies of cholinesterase inhibitor (ChEI) treatment in Alzheimer's disease (AD) indicate that the short and long term actions of ChEIs are dissimilar. fMRI studies of the ChEI rivastigmine have focused on its short term action. In this exploratory study the effect of prolonged (20 weeks) rivastigmine treatment on regional brain activity was measured with fMRI in patients with mild AD. Eleven patients with probable AD and nine age-matched controls were assessed with a Pyramids and Palm Trees semantic association and an n-back working memory fMRI paradigm. In the patient group only, the assessment was repeated after 20 weeks of treatment. There was an increase in task-related brain activity after treatment with activations more like those of normal healthy elderly. Behaviorally, however, there were no significant differences between baseline and retest scores, with a range of performance probably reflecting variation in drug efficacy across patients. Variable patient response and drug dynamic/kinetic factors in small patient groups will inevitably bias (either way) the effect size of any relevant drug related changes in activation. Future studies should take drug response into account to provide more insight into the benefits of ChEI drugs at the individual level.

Economic considerations in the management of Alzheimer's disease

Alzheimer’s disease is a devastating chronic disease that significantly increases healthcare costs and affects the quality of life (QoL) of the afflicted patients and their caregivers. Population aging and other demographic changes may further increase the already staggering costs of this devastating disease. While few pharmacoeconomic studies have used a prospective health economics design to assess resource utilization, most studies showed beneficial treatment effects and suggested potential savings in healthcare costs and reductions in caregiver burden. Various degrees of cost savings have been reported depending on the type of economic model, treatment evaluated, and region used in the studies. Direct comparisons of the results are difficult because different methods have been used in these evaluations. The preference of patients and families for home care for as long as possible suggests that promoting noninstitutional care for these patients should become a priority. Continued home care for patients under pharmacological treatment may reduce caregiver burden, healthcare costs, and ultimately improve patients’ and caregivers’ QoL.

Treatment of Alzheimer's disease across the spectrum of severity

Alzheimer’s disease (AD) is the most common cause of dementia affecting nearly 18 million people around the world and 4.5 million in the US. It is a progressive neurodegenerative condition that is estimated to dramatically increase in prevalence as the elderly population continues to grow. As the cognitive and neuropsychiatric signs and symptoms of AD progresses in severity over time, affected individuals become increasingly dependent on others for assistance in performing all activities of daily living. The burden of caring for someone affected by the disorder is great and has substantial impact on a family’s emotional, social and financial well-being. In the US, the currently approved medications for the treatment of mild to moderate stages of AD are the cholinesterase inhibitors (ChEIs). Cholinesterase inhibitors have shown modest efficacy in terms of symptomatic improvement and stabilization for periods generally ranging from 6 to 12 months. There are additional data that have emerged, which suggest longer-term benefits. For the moderate to severe stages of AD, memantine, an N-methyl-D-aspartate (NMDA) receptor antagonist is in widespread use and has shown modest benefit as monotherapy and in combination with ChEIs. The cost effectiveness of the currently available therapeutic agents for AD has undergone great scrutiny and remains controversial, especially outside the US. Neuropsychiatric symptoms such as agitation and psychosis are common in AD. Unfortunately, in the US there are no Food and Drug Administration (FDA)-approved agents for the treatment of these symptoms, although atypical antipsychotics have shown some efficacy and have been widely used. However, the use of these agents has recently warranted special caution due to reports of associated adverse effects such as weight gain, hyperlipidemia, glucose intolerance, cerebrovascular events, and an increased risk for death. Alternative agents used to treat neuropsychiatric symptoms include serotonergic antidepressants, benzodiazepines, and anticonvulsant medications.

Long-term cost-effectiveness of donepezil for the treatment of Alzheimer's disease

BACKGROUND

(Acetyl-)cholinesterase (ChE) inhibitors have been approved for the treatment of mild to moderate Alzheimer's disease (AD). However, use of ChE inhibitors is limited by budget constraints and disincentives on the side of health insurances and nursing care insurances.

OBJECTIVE

To analyse under what conditions the application of the acetylcholinesterase inhibitor donepezil is favourable for the treatment of patients with AD from the perspective of health insurance and nursing care insurance companies in Germany, taking into account factors such as start and duration of treatment, duration of follow-up, drug costs, internalization of opportunity costs and varying mortality and efficacy rates.

METHODS

Transition probabilities from a Swedish study and German cost data for donepezil were merged in a Markov model to follow a cohort of patients over a period of 5-10 years. We defined a base case with 1 year treatment and follow-up over 5 years and varied treatment length, follow-up interval and cost factors in sensitivity analyses.

RESULTS

In the base case, the ChE inhibitor donepezil did not lead to cost savings but to a cost-effective outcome on side of health insurances and nursing care insurances. Early treatment of AD and internalization of opportunity costs (caring time devoted to patients) led to less costs per quality adjusted life years gained. However, results are very sensitive with respect to varying mortality and efficacy rates.

CONCLUSION

The application of donepezil may be cost-effective, but considerable uncertainties remain. Moreover, the way the reimbursement system in Germany is presently arranged does not support the application of ChE inhibitors.

Difficult behaviors in long-term care patients with dementia

Difficult behaviors are relatively common challenges that can occur throughout the natural progression of dementia, but are particularly common in the mid to late stages of disease. These behaviors can be challenging to manage in nursing and assisted care facilities, and can cause distress to the caregivers and to the patients themselves. Our ability to manage these symptoms can have a profound effect on the patient's quality of life. This article reviews the appropriate assessment of behavioral and psychological symptoms of dementia (BPSD) and the literature supporting various nonpharmacologic and pharmacologic treatments. Nonpharmacologic approaches should be the initial focus for treatment of most BPSD, but should these prove inadequate, a variety of medications are available with varying degrees of clinical research to support their use in ameliorating BPSD.