Analyzing the impact of 23 mg/day donepezil on language dysfunction in moderate to severe Alzheimer's disease

Are pharmacotherapeutics effective for treating aphasia?

INTRODUCTION

Aphasia is a communication disorder resulting from stroke and/or neurodegenerative conditions which involve the left cerebral hemisphere. It is a debilitating disorder affecting a person's ability to speak, understand, read, and write. Its impact on daily life necessitates therapeutic strategies to aid patients with aphasia.

AREAS COVERED

In this special report, the authors speculate whether current pharmacotherapeutic strategies are effective in treating aphasia. The authors look at aphasia caused by different conditions and how this could impact therapy before providing the reader with their expert perspectives. The aim of this paper is for the reader to gain a clearer understanding of the efficacy of the current pharmacotherapeutic treatment paradigms as well as potential future developments.

EXPERT OPINION

The exploration of pharmacotherapy for aphasia in vascular brain disorders and neurodegenerative diseases has received much attention in recent years with various therapeutic strategies having been put forward. In terms of whether pharmacotherapy is effective for the treatment of aphasia, there is still no clear-cut answer. Further research is needed with more studies requiring a greater emphasis on language and communication deficits. Biomarkers may also help clinicians provide their patients with a more personalized treatment plan.

Turning the Spotlight to Cholinergic Pharmacotherapy of the Human Language System

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

Effects of GV1001 on Language Dysfunction in Patients With Moderate-to-Severe Alzheimer's Disease: Post Hoc Analysis of Severe Impairment Battery Subscales

Background and Purpose

The efficacy and safety of GV1001 have been demonstrated in patients with moderate-to-severe Alzheimer's disease (AD). In this study, we aimed to further demonstrate the effectiveness of GV1001 using subscales of the Severe Impairment Battery (SIB), which is a validated measure to assess cognitive function in patients with moderate-to-severe AD.

Methods

We performed a post hoc analysis of data from a 6 month, multicenter, phase 2, randomized, double-blind, placebo-controlled trial with GV1001 (ClinicalTrials.gov, NCT03184467). Patients were randomized to receive either GV1001 or a placebo for 24 weeks. In the current study, nine subscales of SIB-social interaction, memory, orientation, language, attention, praxis, visuospatial ability, construction, and orientation to name- were compared between the treatment (GV1001 1.12 mg) and placebo groups at weeks 12 and 24. The safety endpoints for these patients were also determined based on adverse events.

Results

In addition to the considerable beneficial effect of GV1001 on the SIB total score, GV1001 1.12 mg showed the most significant effect on language function at 24 weeks compared to placebo in both the full analysis set (FAS) and per-protocol set (PPS) (p=0.017 and p=0.011, respectively). The rate of adverse events did not differ significantly between the 2 groups.

Conclusions

Patients with moderate-to-severe AD receiving GV1001 had greater language benefits than those receiving placebo, as measured using the SIB language subscale.

Proportion of Women and Reporting of Outcomes by Sex in Clinical Trials for Alzheimer Disease: A Systematic Review and Meta-analysis

IMPORTANCE

Women represent two-thirds of patients with Alzheimer disease (AD), and sex differences might affect results of randomized clinical trials (RCTs). However, little information exists on differences in sex as reported in RCTs for AD.

OBJECTIVE

To assess the ratio of females to males and the reporting of sex-stratified data in large pharmaceutical RCTs for AD.

DATA SOURCES

A search for pharmaceutical RCTs for AD was conducted on September 4, 2019, using ClinicalTrials.gov with the key word Alzheimer disease, and articles related to those trials were identified using the PubMed, Scopus, and Google Scholar databases. Searches were conducted between September 4 and October 31, 2019, and between April 15 and May 31, 2020.

STUDY SELECTION

Controlled RCTs that had more than 100 participants and tested the efficacy of drugs or herbal extracts were included. Of 1047 RCTs identified, 409 were published and therefore screened. A total of 77 articles were included in the final analysis, including 56 primary articles on AD, 13 secondary articles on AD, and 8 articles on mild cognitive impairment.

DATA EXTRACTION AND SYNTHESIS

The location and date of publication; number, sex, and age of patients enrolled; disease severity; experimental or approved status of the drug; and whether the study included a sex-stratified analysis in the protocol, methods, or results were extracted by 1 reviewer for each article, and the meta-analysis followed the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guideline. Data were analyzed using a mixed-effects model.

MAIN OUTCOMES AND MEASURES

The mean proportion of women enrolled in the trials and the associations between prespecified variables were analyzed. The proportion of articles that included sex-stratified results and the temporal trends in the reporting of these results were also studied.

RESULTS

In this review of 56 RCTs for AD involving 39 575 participants, 23 348 women (59.0%) were included. The mean (SD) proportion of women in RCTs of approved drugs was 67.3% (6.9%), and in RCTs of experimental drugs was 57.9% (5.9%). The proportion of women in RCTs of experimental drugs was significantly lower than the proportion of women in the general population with AD in the US (62.1%; difference, -4.56% [95% CI, -6.29% to -2.87%]; P < .001) and Europe (68.2%; difference, -10.67% [95% CI, -12.39% to -8.97%]; P < .001). Trials of approved drugs had a higher probability of including women than trials of experimental drugs (odds ratio [OR], 1.26; 95% CI, 1.05-1.52; P = .02). Both the severity of AD at baseline and the trial location were associated with the probability of women being enrolled in trials (severity: OR, 0.98; 95% CI, 0.97-1.00; P = .02; location in Europe: OR, 1.26; 95% CI, 1.05-1.52; P = .01; location in North America: OR, 0.81; 95% CI, 0.71-0.93; P = .002). Only 7 articles (12.5%) reported sex-stratified results, with an increasing temporal trend (R, 0.30; 95% CI, 0.05-0.59; P = .03).

CONCLUSIONS AND RELEVANCE

In this systematic review and meta-analysis, the proportion of women in RCTs for AD, although higher than the proportion of men, was significantly lower than that in the general population. Only a small proportion of trials reported sex-stratified results. These findings support strategies to improve diversity in enrollment and data reporting in RCTs for AD.

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.

Cognitive Profiles on the Severe Impairment Battery Are Similar in Alzheimer Disease and Down Syndrome With Dementia

Previous research has revealed similarities in the neuropathology, clinical presentation, and risk factors between persons with Alzheimer disease from the general population (GP-AD) and those with Down syndrome (DS-AD). Less is known, however, about the extent of similarities and differences in the cognitive profiles of these 2 populations. Fifty-one moderate to severely demented GP-AD and 59 DS-AD individuals participated in this study which compared the cognitive profiles of these 2 populations on the Severe Impairment Battery (SIB), controlling for sex as well as level of functional ability using a modified version of the Bristol Activities of Daily Living Scale. Overall, the neuropsychological profiles of the higher-functioning individuals within the DS-AD and advanced GP-AD groups, as represented by mean difference scores on the SIB as a whole and across the 9 separate cognitive domains, were very similar to one another after adjusting for sex and functional impairment. To our knowledge, this is the first study to directly compare the cognitive profiles of these 2 populations on the SIB. Findings suggest that the underlying dementia in GP-AD and DS-AD may have corresponding and parallel effects on cognition.

Clinical Recommendations for the Use of Donepezil 23 mg in Moderate-to-Severe Alzheimer's Disease in the Asia-Pacific Region

Background

The ‘Asia-Pacific Expert Panel (APEX) for donepezil 23 mg’ met in November 2015 to review evidence for the recently approved high dose of donepezil and to provide recommendations to help physicians in Asia make informed clinical decisions about using donepezil 23 mg in patients with moderate-to-severe Alzheimer's disease (AD).

Summary

In a global phase III study (study 326) in patients with moderate-to-severe AD, donepezil 23 mg/day demonstrated significantly greater cognitive benefits versus donepezil 10 mg/day, with a between-treatment difference in mean change in the Severe Impairment Battery score of 2.2 points (p < 0.001) in the overall population and 3.1 points (p < 0.001) in patients with advanced AD. A subanalysis of study 326 demonstrated that the benefits and risks associated with donepezil 23 mg/day versus donepezil 10 mg/day in Asian patients with moderate-to-severe AD were comparable to those in the global study population.

Key Message

Donepezil 23 mg is a valuable treatment for patients with AD, particularly those with advanced disease. The APEX emphasized the importance of patient selection (AD severity, tolerability of lower doses of donepezil, and absence of contraindications), a stepwise titration strategy for dose escalation, and appropriate monitoring and counseling of patients and caregivers in the management of patients with AD.

Donepezil modulates the endogenous immune response: implications for Alzheimer's disease

OBJECTIVE

Donepezil (DNPZ) is a drug commonly used for Alzheimer's disease (AD) that may favour a T helper 2 phenotype leading to increased naturally occurring auto-antibodies (NAb) against beta-amyloid (Aβ). We hypothesized the involvement of the cholinergic receptors [α7-nicotnic acetylcholine receptor (α7nAChR)] expressed on peripheral blood mononuclear cells (PBMC).

METHODS

Fifty patients with mild-to-moderate AD, DNPZ treated (DNPZ+, n = 25) or not (DNPZ-, n = 25), and 25 matched controls were enrolled and PBMC extracted for both in vitro cultures, and real-time polymerase chain reaction and chromatin immunoprecipitation assay. Plasma samples were also obtained for Aβ and NAb determination.

RESULTS

Donepezil increased in vitro the expression of the transcription factor GATA binding protein 3 (GATA3) through α7nAChR, because prevented by the specific antagonist methyllycaconitine. Ex vivo PBMC α7nAChR mRNA expression was increased in both AD groups, while GATA3 expression was not. A significant increase in the GATA3/interleukin 5 promoter association was found in DNPZ+ patients. Finally, DNPZ+ patients showed both significantly higher plasma levels of anti-Aβ NAb with respect to DNPZ- patients and Aβ 1-42 with respect to normal controls.

CONCLUSIONS

Donepezil might modulate a T helper 2 bias via α7nAChR leading to increased expression of NAb. Further studies on the role of the modulation of the immune response against Aβ may pave the way to innovative therapeutic strategies for AD. Copyright © 2016 John Wiley & Sons, Ltd.

Alzheimer's disease and language impairments: social intervention and medical treatment

Communication is very important for people to be successfully integrated into social environment and make and maintain relationship. Particularly, language difficulties lead to social exclusion of the people affected with Alzheimer's disease (AD) and contribute to a significant decrease in the quality of their life and also have a big impact on their family members who in most cases become their caregivers who need to communicate with their loved ones in order to meet their needs. Therefore, the goal of this study is to describe language impairments in the individual phases of AD and discuss their improvement with respect to AD on the basis of literature review. The authors of this article use traditional research methods in order to achieve the goal set mentioned earlier. First, a method of literature review of available sources describing language impairments in the individual phases of AD is exploited. Second, to show how informal caregivers and relevant drugs can successfully intervene in the improvement of these language impairments, a method of comparison of different research studies exploring such social intervention and medical treatment is used.

Evaluation of an 8-item Severe Impairment Battery (SIB-8) vs. the full SIB in moderate to severe Alzheimer's disease patients participating in a donepezil study

AIM

The Severe Impairment Battery (SIB), a reliable cognitive measure for evaluating treatment response in advanced Alzheimer's disease (AD), takes approximately 20 min to administer. A recently derived 8-item version of the SIB - the SIB-8 - which takes about 3 min to administer, may represent a more convenient tool for use in clinical practice. The current analyses further explored the SIB-8 scale with respect to its validity and sensitivity.

METHODS

A post hoc analysis was performed using data from a 24-week trial of donepezil 23 mg/day and 10 mg/day in > 1400 patients with moderate to severe AD [baseline Mini-Mental State Examination (MMSE) score 0-20]. Treatment effects on cognition (patterns of score change) were assessed using the full SIB and SIB-8 in the total study population and subgroups based on concomitant memantine use and baseline MMSE. Internal consistency/agreement and correlations between the SIB and SIB-8 and other clinical end points were evaluated.

RESULTS

Assessment of score changes from baseline to week 24 with donepezil (23 or 10 mg/day) demonstrated comparable patterns of change when using the SIB-8 and the full SIB, despite inherent differences in the total score ranges for the two scales. Internal consistency/agreement between the full SIB and SIB-8 was good (Cronbach's alphas: 0.77-0.95). SIB-8 scores reliably correlated with SIB total scores (r = 0.859, baseline; r = 0.900, week 24; p < 0.0001), as well as MMSE scores (r = 0.7163, baseline; r = 0.7963, week 24; p < 0.0001). Scores on both SIB scales were moderately associated with functional measures at baseline and week 24.

CONCLUSIONS

In this post hoc analysis, similar treatment effects were measured by the full SIB and the SIB-8. Very good internal consistency/agreement and strong correlations between the SIB and the more rapid and convenient SIB-8 indicate that the SIB-8 may be a useful and efficient clinical proxy for the full SIB in evaluating treatment response in patients with advanced AD.

Language impairment in Alzheimer's disease and benefits of acetylcholinesterase inhibitors

Alzheimer’s disease is characterized by progressively worsening deficits in several cognitive domains, including language. Language impairment in Alzheimer’s disease primarily occurs because of decline in semantic and pragmatic levels of language processing. Given the centrality of language to cognitive function, a number of language-specific scales have been developed to assess language deficits throughout progression of the disease and to evaluate the effects of pharmacotherapy on language function. Trials of acetylcholinesterase inhibitors, used for the treatment of clinical symptoms of Alzheimer’s disease, have generally focused on overall cognitive effects. However, in the current report, we review data indicating specific beneficial effects of acetylcholinesterase inhibitors on language abilities in patients with Alzheimer’s disease, with a particular focus on outcomes among patients in the moderate and severe disease stages, during which communication is at risk and preservation is particularly important.

Aspects of communication in Alzheimer's disease: clinical features and treatment options

BACKGROUND

During the course of Alzheimer's disease (AD), cognitive processes, including language and communication, become increasingly impaired. The aim of this review was to highlight the impact of communication deficits in AD, and discuss the need for effective treatments.

METHOD

PubMed was searched for studies relating to language and communication in AD. The publications identified were used as a basis for the commentary in this paper. Studies relating to the clinical effectiveness of pharmacological treatment for language and communication issues were identified systematically.

RESULTS

Communication deficits are common in AD. From the earliest disease stage, the patient's capacity for communication declines as problems develop with the use of language and all aspects of functional communication. There is a loss of the ability to communicate thoughts and needs, and it becomes increasingly difficult to interact socially and sustain personal relationships with caregivers, family, and friends. It is unsurprising that patients become frustrated at their loss of self-expression, and studies have demonstrated that impaired communication is strongly linked with the development of significant behavioral concerns. Overall, poor communication contributes to caregiver strain, and adds notably to the burden of disease. Clinical data and post-hoc analyses provide preliminary indications that anti-AD therapies (memantine and the cholinesterase inhibitors, ChEIs) and non-pharmacological cognitive-linguistic stimulation techniques may be helpful in addressing communication difficulties.

CONCLUSIONS

The capacity to treat or slow the progression of communication deficits in AD would prolong patient independence, and have a profound impact on the quality of life of patients and caregivers. The use of pharmacological (anti-AD therapies) and non-pharmacological (cognitive-linguistic stimulation) treatments may be useful management methods and warrant further investigation.

High-dose donepezil (23 mg/day) for the treatment of moderate and severe Alzheimer's disease: drug profile and clinical guidelines

To provide healthcare professionals with a comprehensive assessment of donepezil 23 mg and its role in treating Alzheimer's disease (AD), the Donepezil 23 mg Expert Working Group (EWG) convened in June 2011 to critically evaluate the clinical trial database for this higher dose formulation and the members' clinical experience with its use. Discussions were based on a large, 6-month, phase 3 clinical trial in patients with moderate to severe AD that compared continuing donepezil 10 mg/day versus switching to 23 mg/day. In this trial, donepezil 23 mg/day demonstrated significantly greater cognitive benefits (mean change in Severe Impairment Battery score, 2.11 points; P < 0.001). Prespecified analyses showed that benefits were significant irrespective of concomitant memantine use. The EWG considered integrating these new data into clinical practice approaches. Dementia severity, tolerability of the 10 mg dose, and need for additional therapy were key selection criteria, as was monitoring of gastrointestinal side effects, as consideration of titration strategies is an important aspect of implementation. The EWG concluded that donepezil 23 mg is an efficacious therapy for moderate to severe AD, with or without concomitant memantine, extending the treatment opportunities available to manage moderate to severe AD dementia. EWG guidelines offer assistance to clinicians in choosing and implementing treatment options.

Effects of donepezil 23 mg on Severe Impairment Battery domains in patients with moderate to severe Alzheimer's disease: evaluating the impact of baseline severity

INTRODUCTION

The US Food and Drug Administration approved a 23 mg daily dose of donepezil for treatment of moderate to severe Alzheimer's disease (AD) based on outcomes from a large trial comparing the 23 mg/day dose with the standard 10 mg/day dose. Results from this study indicated that after 24 weeks, donepezil 23 mg/day provided significant cognitive benefits over donepezil 10 mg/day, measured using the Severe Impairment Battery (SIB). In the analyses reported herein, we further characterize the range of cognitive domains impacted by treatment with donepezil 23 mg/day.

METHODS

A post hoc analysis was conducted using data from a 24-week, randomized, double-blind trial comparing donepezil 23 mg/day versus 10 mg/day in 1,467 patients with moderate to severe AD (baseline Mini-Mental State Examination (MMSE) score 0 to 20). Changes from baseline to week 24 in the nine SIB domain scores were analyzed in the intent-to-treat (ITT) population (baseline MMSE 0 to 20), in patients with more severe baseline AD (MMSE 0 to 16), and in severity strata based on baseline MMSE scores (0 to 5, 6 to 10, 11 to 15, 16 to 20).

RESULTS

In the ITT population, changes in six of the nine SIB domains favored donepezil 23 mg/day over donepezil 10 mg/day. LS mean treatment differences were significant for the language, visuospatial ability, and construction domains. In the more advanced cohort of patients (MMSE 0 to 16 at baseline), LS mean treatment differences were statistically significant favoring donepezil 23 mg/day in five of the nine domains: language, memory, visuospatial ability, attention, and construction. Descriptive analysis of LS mean changes in SIB domain scores in the four baseline severity strata showed variable patterns of response; overall, cognitive benefits of donepezil 23 mg/day were greatest in patients with MMSE scores of 0 to 15.

CONCLUSIONS

These results suggest that donepezil 23 mg/day provides benefits over 10 mg/day across a range of cognitive domains. The magnitude of benefit and domains impacted varied depending on the stage of AD; significant benefits with higher dose donepezil were most apparent at more advanced stages of AD and were most prominent in the language domain.

Galantamine versus donepezil in Chinese patients with Alzheimer's disease: results from a randomized, double-blind study

BACKGROUND

Acetylcholinesterase inhibitors are considered standard of care for Alzheimer's disease in many countries. Galantamine is an acetylcholinesterase inhibitor that may also act via allosteric modulation of nicotinic acetylcholine receptors. Therefore, it may provide benefits compared with other acetylcholinesterase inhibitors. The present study compared galantamine (n = 116) with donepezil (n = 117) in a double-blind trial at nine hospitals in China.

METHODS

After washout of any previous acetylcholinesterase inhibitors, subjects with mild to moderate Alzheimer's disease received galantamine or donepezil for 16 weeks.

RESULTS

Alzheimer's Disease Assessment Scale - cognitive subscale (ADAS-cog/11) scores improved significantly from baseline in both treatment arms, with a significant difference in favor of galantamine on the "language" functional area (P = 0.035). Significantly more galantamine-treated patients responded to treatment (defined as a reduction in ADAS-cog/11 score of >4, >7, or >10 points; all P < 0.05), and had an ADAS-cog/11 score < 20 at end point (P = 0.015). Both treatments were well tolerated, although fewer galantamine-treated patients experienced gastrointestinal adverse events compared with donepezil (30% versus 48%).

CONCLUSION

Cognitive function improved significantly in subjects with mild to moderate Alzheimer's disease treated with galantamine or donepezil, and both treatments were generally well tolerated. Significant benefits for galantamine over donepezil were observed for language and response to treatment.

Cognitive Enhancers in Moderate to Severe Alzheimer's Disease

The treatment of moderate to severe Alzheimer's disease is reviewed with regard to mechanisms of action, pharmacokinetics, metabolism, safety/tolerability, and efficacy in reducing cognitive, behavioral/psychiatric, functional and global symptoms. The cholinesterase inhibitors donepezil, rivastigmine and galantamine and the N-methyl-d-aspartate receptor channel blocker memantine are moderately beneficial. Small improvements over a few months are followed by slowed mental decline. Concerning cognitive, functional and global functions, these drugs are similarly effective. Cholinesterase inhibitors also reduce apathy, memantine counteracts agitation and aggression. Serious adverse effects are rare with all four drugs. Cholinesterase inhibitors bear a risk for patients with cardiac diseases. Adverse emetic events are typical for oral formulations of these drugs, but less for rivastigmine transdermal patches. Other routes of administration and use of a galantamine prodrug are currently investigated. The superiority of combination therapies over monotherapies requires further support. Promising investigational drugs include the copper/zinc ionophore PBT2 and multifunctional hybrid molecules.