Memantine in moderate to severe Alzheimer's disease: a meta-analysis of randomised clinical trials

Memantine and cholinesterase inhibitor combination therapy for Alzheimer's disease: a systematic review

BACKGROUND

Memantine is licensed for moderate-to-severe Alzheimer's disease (AD). National Institute for Clinical Excellence (NICE) guidance does not recommend the use of memantine in combination with cholinesterase inhibitors (acetylcholinesterase inhibitor (AChEI)). The underpinning meta-analysis was disputed by the manufacturer.

OBJECTIVES

To compare the efficacy of AChEI monotherapy with combination memantine and AChEI therapy in patients with moderate-to-severe AD and to examine the impact of including unpublished data on the results.

DESIGN

Systematic review and meta-analysis of randomised controlled trials.

DATA SOURCES

The Cochrane Dementia Group trial register, ALOIS, searched for the last time on 3 May 2011.

DATA SYNTHESIS

Data from four domains (clinical global, cognition, function, behaviour and mood) were pooled. Sensitivity analyses examined the impact on the NICE-commissioned meta-analysis of restricting data to patients with moderate-to-severe AD and of including an unpublished trial of an extended release preparation of memantine.

RESULTS

Pooled data from the trials, which were included in the NICE-commissioned meta-analysis but which were restricted to moderate-to-severe AD only, showed a small effect of combination therapy on cognition (standardised mean difference (SMD)=-0.29, 95% CI -0.45 to -0.14). Adding data from an unpublished trial of an extended release memantine (total three trials, 1317 participants) showed a small benefit of combination therapy on global scores (SMD=-0.20, 95% CI -0.31 to -0.09), cognition (SMD=-0.25, 95% CI -0.36 to -0.14) and behaviour and mood (SMD=-0.17, 95% CI -0.32 to -0.03) but not on function (SMD=-0.04, 95% CI -0.21 to 0.13) at 6 months. No clinical data have been reported from a 1-year trial, although this found 'no significant benefit' on any clinical measures at 1 year.

CONCLUSIONS

These results suggest that there may be a small benefit at 6 months of adding memantine to AChEIs. However, the impact on clinical global impression depends on exactly which studies are included, and there is no benefit on function, so its clinical relevance is not robustly demonstrated. Currently available information from randomised controlled trails indicates no benefit of combination therapy over monotherapy at 1 year. Legislation on the form and content of registry posted results is needed in Europe.

Economic evaluation of the impact of memantine on time to nursing home admission in the treatment of Alzheimer disease

OBJECTIVE

An observational study showed that combining memantine with a cholinesterase inhibitor (ChEI) treatment significantly delayed admission to nursing homes in patients with Alzheimer disease (AD). Our study aimed to evaluate the economic impact of the concomitant use of memantine and a ChEI, compared with a ChEI alone, in a Canadian population of patients with AD.

METHOD

A cost-utility analysis using a Markov model during a 7-year time horizon was performed according to a societal and Canadian health care system perspective. The Markov model includes the following states: noninstitutionalized, institutionalized, and deceased. The model includes transition probabilities for institutionalization and death, adjusted with mortality rates specific to AD. Utilities associated with institutionalization and noninstitutionalization were included. For the health care system perspective, costs of medication as well as costs of care provided in the community and in nursing homes were considered. For the societal perspective, costs of direct care and supervision provided by caregivers were added.

RESULTS

From both perspectives, the concomitant use of a ChEI and memantine is a dominant strategy, compared with the use of a ChEI alone. On a per patient basis, there was a gain of 0.26 quality-adjusted life years with the treatment including memantine and cost decreases of Can$21 391 and Can$30 512, respectively, for the societal and health care system perspective.

CONCLUSIONS

This economic evaluation indicates that institutionalization is the largest cost component in AD management and that the use of memantine, combined with a ChEI, to treat AD is a cost-effective alternative, compared with the use of a ChEI alone.

Reasons for psychiatric medication prescription for new nursing home residents

OBJECTIVES

This article focuses on justification of psychoactive medication prescription for NH residents during their first three months post-admission.

METHOD

We extracted data from 73 charts drawn from a convenience sample of individuals who were residents of seven nursing homes (NHs) for at least three months during 2009. Six focus groups with NH staff were conducted to explore rationales for psychoactive medication usage.

RESULTS

Eighty-nine percent of the residents who received psychoactive medications during the first three months of residence had a psychiatric diagnosis, and all residents who received psychoactive medications had a written physician's order. Mental status was monitored by staff, and psychoactive medications were titrated based on changes in mental status. One concern was that no Level II Preadmission Screening and Annual Resident Review (PASRR) evaluations were completed during the admissions process. Further, while 73% had mental health diagnoses at admission, 85% of the NH residents were on a psychoactive medication three months after admission, and 19% were on four or more psychoactive medications. Although over half of the residents had notes in their charts regarding non-psychopharmacological strategies to address problem behaviors, their number was eclipsed by the number receiving psychopharmacological treatment.

CONCLUSIONS

While the results suggest that NHs may be providing more mental health care than in the past, psychopharmacological treatment remains the dominant approach, perhaps because of limited mental health training of staff, and lack of diagnostic precision due to few trained geriatric mental health professionals. A critical review of the role of the PASRR process is suggested.

Treatment of Alzheimer's disease in Brazil: I. Cognitive disorders

This article reports the recommendations of the Scientific Department of Cognitive Neurology and Aging of the Brazilian Academy of Neurology for the treatment of Alzheimer’s disease (AD) in Brazil, with special focus on cognitive disorders. It constitutes a revision and broadening of the 2005 guidelines based on a consensus involving researchers (physicians and non-physicians) in the field. The authors carried out a search of articles published since 2005 on the MEDLINE, LILACS and Cochrane Library databases. The search criteria were pharmacological and non-pharmacological treatment of cognitive disorders in AD. Studies retrieved were categorized into four classes, and evidence into four levels, based on the 2008 recommendations of the American Academy of Neurology. The recommendations on therapy are pertinent to the dementia phase of AD. Recommendations are proposed for the treatment of cognitive disorders encompassing both pharmacological (including acetyl-cholinesterase inhibitors, memantine and other drugs and substances) and non-pharmacological (including cognitive rehabilitation, physical activity, occupational therapy, and music therapy) approaches. Recommendations for the treatment of behavioral and psychological symptoms of dementia due to Alzheimer’s disease are included in a separate article of this edition.

Validity and responsiveness to change of clinically derived MDS scales in Alzheimer disease outcomes research

This analysis assessed 3 subscales derived from the nursing home Minimum Data Set (MDS), the Cognitive Performance Scale (CPS), Depression Rating Scale (DRS), and Aggressive Behavior Scale (ABS), as outcome measures in clinical trials of long-term care residents with Alzheimer disease (AD). A total of 26 patients with moderate-to-severe AD and agitation/aggression enrolled in a trial of memantine were assessed using the Mini-Mental State Examination (MMSE), Neuropsychiatric Inventory Nursing Home Version (NPI-NH), and the Cohen-Mansfield Agitation Inventory (CMAI) administered by trained researchers. MDS data were collected as part of their standard clinical care. The MDS subscales correlated significantly with their corresponding research scales: CPS and MMSE (r = -0.57, P = .003); DRS and NPI-NH total (r = 0.42, P = .038); DRS and NPI-NH depression (r = 0.41, P = .04), and ABS and CMAI (r = 0.54, P = .004). DRS and ABS scores did not change significantly from baseline to 3 months though the NPI-NH and CMAI did, indicating limited sensitivity to change. This suggests that the MDS subscales measure comparable aspects of cognitive function and depressive and agitated/aggressive behavior as the MMSE, NPI-NH, and CMAI. However, this analysis also suggests that sensitivity to change of the DRS and ABS may be limited compared to the NPI-NH and CMAI. As these findings are preliminary, further research is needed to determine the utility of MDS scales in outcomes research.

Memantine in moderate to severe Alzheimer's disease: an observational post-marketing study

Memantine is an N-methyl-D: -aspartate (NMDA) receptor antagonist, approved for the treatment of moderate to severe Alzheimer's disease (AD). We conducted a 4-month observational, post-marketing, Austrian study of memantine in 377 outpatients with moderate to severe AD. In this 'real-life' setting, memantine was well-tolerated, and produced benefits in cognition (Mini-Mental State Examination), activities of daily living (Activities of Daily Living score), and global function (Clinical Global Impression scale). Treatment effects were apparent in both pre-treated and treatment-naïve patient subgroups.

Prescribing trends in cognition enhancing drugs in Australia

BACKGROUND

This study sought to examine the trends in the prescribing of subsidized and unsubsidized cognition enhancing drugs (CEDs) in Australia over five years from 2002 to 2007. Subsidized cholinesterase inhibitor medication could be prescribed to people with mild to moderate Alzheimer's disease (AD) once a specialist physician had confirmed this diagnosis. Memantine was available for use in moderately severe AD but not subsidized.

METHODS

We analyzed the Medicare Australia and Drug Utilisation Sub-Committee databases for CED prescription data, 2002-2007, by gender, age and prescriber class. Aggregated prescription data for each medication were converted to defined daily doses (DDD) per 1000 persons per day using national census data.

RESULTS

There were 1,583,667 CED prescriptions dispensed during the study period. CED use increased 58% from 0.91 to 1.56 DDD/1000 persons/day between 2002 and 2007. Peak use was in those aged 85-89 years. Age-adjusted utilization was slightly higher in females than males. Donepezil was the most widely used CED (66%), followed by galantamine (27%) then memantine (4%). General practitioners prescribed the majority of CEDs. Geriatricians exhibited a greater preference for galantamine than other prescribers. CED dispensing peaked towards the end of each calendar year, reflecting stockpiling by patients under the influence of a federal safety net subsidy.

CONCLUSIONS

Despite subsidized access to CEDs in Australia, only a minority of people with AD was prescribed these drugs during the period of the study. It is likely that the combination of complex prescribing rules and negative perceptions about efficacy or cost-effectiveness might have contributed to these findings.

Treatment with cholinesterase inhibitors and memantine of patients in the Alzheimer's Disease Neuroimaging Initiative

OBJECTIVES

To assess the clinical characteristics and course of patients with mild cognitive impairment (MCI) and mild Alzheimer disease (AD) treated with cholinesterase inhibitors (ChEIs) and memantine hydrochloride.

DESIGN

Cohort study.

SETTING

The 59 recruiting sites for the Alzheimer's Disease Neuroimaging Initiative (ADNI).

PARTICIPANTS

Outpatients with MCI and AD in ADNI.

MAIN OUTCOME MEASURES

The AD Assessment Scale-cognitive subscale (ADAS-cog), Mini-Mental State Examination (MMSE), Clinical Dementia Rating (CDR) scale, and Functional Activities Questionnaire (FAQ).

RESULTS

A total of 177 (44.0%) of 402 MCI patients and 159 (84.6%) of 188 mild-AD patients were treated with ChEIs and 11.4% of MCI patients and 45.7% of AD patients with memantine at entry. Mild-cognitive-impairment patients who received ChEIs with or without memantine were more impaired, showed greater decline in scores, and progressed to dementia sooner than patients who did not receive ChEIs. Alzheimer-disease patients who received ChEIs and memantine took them longer, were more functionally impaired, and showed greater decline on the MMSE and CDR (but not on the ADAS-cog or FAQ) than those who received ChEIs only.

CONCLUSIONS

Academic physicians frequently prescribe ChEIs and memantine earlier than indicated in the US Food and Drug Administration-approved labeling to patients who are relatively more severely impaired or who are rapidly progressing toward cognitive impairment. The use of these medications in ADNI is associated with clinical decline and may affect the interpretation of clinical trial outcomes.

STUDY REGISTRATION

clinicalTrials.gov Identifier: NCT00106899.

An open-label, multicenter observational study for patients with Alzheimer's disease treated with memantine in the clinical practice

Background/Aims

In this post-marketing observational study, the safety and effectiveness of memantine were evaluated in patients with Alzheimer's disease (AD).

Methods

In a 6-month, observational, open-label study at 202 specialist sites in Greece, the effectiveness of memantine was evaluated using the Mini-Mental State Examination (MMSE) and the Instrumental Activities of Daily Living (IADL) scale at baseline, and after 3 and 6 months. Discontinuation rates and adverse drug reactions (ADRs) were also recorded to evaluate the safety profile of memantine.

Results

2,570 patients participated in the study. Three and 6 months after baseline, MMSE and IADL scores were significantly improved compared to baseline. At the end of the study, 67% of the patients had improved their MMSE score; 7.1% of the patients reported ≥1 ADRs, and treatment was discontinued due to ADR in 0.7%.

Conclusion

Memantine was well tolerated and had a positive effect on the patient's cognitive and functional ability in real-life clinical practice, in agreement with randomized, controlled trials.

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

BACKGROUND/AIMS

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

METHODS

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

RESULTS

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

CONCLUSION

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

Memantine for non-motor features of Parkinson's disease: a double-blind placebo controlled exploratory pilot trial

OBJECT

To perform an exploratory study evaluating memantine for several common non-motor problems in Parkinson's disease.

METHODS

We conducted a single center, double-blind, placebo controlled pilot trial of memantine, titrated to 20 mg/day, in PD subjects. Inclusion criteria were intentionally broad and included both fluctuating and non-fluctuating patients. After baseline assessments, subjects (N = 40) were randomized to drug and placebo groups. They received a battery of traditional and non-motor assessments. After a safety call (2 weeks after baseline) they returned for identical assessments at week 8. An 8-week open label extension was started if desired.

RESULTS

Subject demographics (age 69.1 ± 7.8; 24 males), were similar in the drug and placebo groups. Four dropped from the study while on drug vs. none on placebo. Two of 36 remaining dropped out over the 8-week open label section. Of the 34 who completed the final open label visit, 24 elected to be prescribed memantine after the study. During the controlled trial, there was no significant change in UPDRS section I or II, Epworth sleepiness scale, fatigue severity scale, Hamilton depression scale, Conner adult inventory, PD Quality of Life-39, or clinical global impressions. UPDRS "on" motor scores tended to improved, p = 0.19.

CONCLUSION

Memantine was well tolerated in PD; however, specific measures of sleepiness, fatigue, depression, and attention did not significantly improve. The majority of subjects elected to stay on the drug after the open label extension suggesting some unassessed benefit.

[Treatment of Alzheimer's disease and future approaches]

The progressive neuronal loss in Alzheimer's disease leads to neurochemical abnormalities which provide the basis for symptomatic treatments. Four cholinesterase inhibitors were released in this indication. Meta-analyses have confirmed a beneficial effect on cognitive functioning and activities of daily living. The NMDA receptor antagonist, memantine, was also approved for the treatment of moderate to severe and may be associated. Progress in the patho-physiology of the disease offers some hope of new treatments acting on the cerebral lesions. The amyloid hypothesis allowed the emergence of active or passive immunotherapies, and of secretase inhibitors or modulators. Recent studies have targeted the P tau protein. The brain plasticity and the uses of stem cells offer more distant hope.

Clinical progression of moderate-to-severe Alzheimer's disease and caregiver burden: a 12-month multicenter prospective observational study

BACKGROUND

Prospective studies on the clinical progression of Alzheimer's disease (AD) and its relationship to caregiver burden are needed to improve illness management and use of resources.

METHODS

This national, multicenter, observational study evaluated 1235 moderate to severe AD patients under routine care in Spain. Baseline cross-sectional sociodemographic and clinical data, and changes from baseline to month 12 of various neuropsychological tests and clinical ratings, including Blessed Dementia Scale, Mini-mental State Examination (MMSE), Hughes Clinical Dementia Rating sum-of-boxes (CDR-SB), Clinical Global Impression of Change (CGIC) and Zarit Caregiver Burden scales, were recorded and comprehensively analyzed.

RESULTS

Baseline data were in accordance with characteristics consistently reported to influence AD risk regarding anthropometrics, sociocultural features and comorbidities. Significant progressive functional impairments (i.e. in routine activities and essential daily tasks) and cognitive (i.e. MMSE and CDR-SB) impairments were found at month 12. However, patients' behavior and caregivers' burden improved slightly, but significantly, corroborating the major influence of behavioral symptoms on caregivers' distress. Caregivers showed significantly lower burden with patients with higher levels of education and, to a lesser extent, when patients received AD-specific medication. Physicians accurately detected AD clinical evolution as their CGIC ratings significantly correlated with all tests.

CONCLUSIONS

These findings reinforce previous AD knowledge and add data on the clinical course of advanced stages of AD. Caregiver burden depended more on patients' behavioral alterations than on their functional or cognitive declines; and it was diminished by their patients having higher levels of education and being treated with AD-specific medications. Research into unexplored factors that might reduce caregiver burden, ultimately benefiting both patients and caregivers, is encouraged.

Memantine benefits functional abilities in moderate to severe Alzheimer's disease

OBJECTIVE

Functional abilities are severely impacted in Alzheimer's disease (AD). Loss of the ability to perform complex (instrumental) and basic activities of daily living (ADL), leads to decreased independence and increased caregiver burden. This post-hoc analysis investigated the effect of memantine (20 mg/day) on ADLs, as measured by Alzheimer's Disease Cooperative Study-Activities of Daily Living 19-item (ADCS-ADL19) and 23-item (ADCS-ADL23) scales, in patients with moderate-to-severe AD.

DESIGN

Data were pooled from six multicenter, randomized, placebo-controlled, double-blind, 6-month studies of memantine 20 mg/day.

PARTICIPANTS

Male and female patients aged ≥ 50 years at baseline with a Mini Mental State Examination (MMSE) score < 20.

MEASUREMENTS

ADCS-ADL19 and ADCS-ADL23 scales were pooled, and 14 shared items, with a score range of 0-45, were identified and included in the analysis (ADL14). Basic ADLs (BADLs) were defined as: eating, walking, toileting, bathing, and grooming. Instrumental ADLs (IADLs) were defined as: using a telephone, watching television, conversing, clearing a table, finding belongings, obtaining a beverage, disposing of household rubbish, travelling outside the house, and being left alone. Changes from baseline on single-item, BADL (range: 0-15), IADL (range: 0-30), and total ADL14 scores were analysed for observed cases using ANCOVA, with study, center and treatment as categorical explanatory variables and score at baseline as a covariate.

RESULTS

959 patients were treated with memantine and 867 patients received placebo. Memantine-treated patients had less decline from baseline on the ADL14 total score, compared with placebo (p < 0.001) at study end. Memantine also showed lower reductions in BADLs (p < 0.05) and IADLs (p < 0.001), for observed cases, compared with placebo. Memantine-treated patients showed less worsening than placebo recipients for the ADL items: toileting (p < 0.01), grooming (p < 0.01), finding belongings (p < 0.01), and travelling outside the house (p < 0.05).

CONCLUSION

Compared with placebo, memantine shows benefits for both basic and instrumental ADLs in patients with moderate-to-severe AD, suggesting that memantine treatment may lead to a more interactive and dignified life for patients with moderate-to-severe AD.

The pharmacoeconomics of cognitive enhancers in moderate to severe Alzheimer's disease

Alzheimer's disease is associated with a substantial economic impact on patients, their caregivers and society. Due to the current rise in the aging population, the prevalence and impact of Alzheimer's disease are expected to increase greatly. The cost of caring for someone with Alzheimer's disease is magnified in the more severe stages of the disease. There are four cognitive enhancers commonly used for the treatment of Alzheimer's disease: three cholinesterase inhibitors (donepezil, rivastigmine and galantamine) and one NMDA receptor antagonist (memantine). Of these, donepezil and memantine have been approved in many countries as pharmacological treatments for moderate to severe Alzheimer's disease, while donepezil, rivastigmine and galantamine are approved treatments for mild to moderate Alzheimer's disease. While cost effectiveness has been well studied in mild to moderate Alzheimer's disease, the cost-benefit information for drug therapy in moderate to severe Alzheimer's disease is less clear. This article reviews the pharmacoeconomic data available on these four drugs, with a specific focus on moderate to severe Alzheimer's disease, including economic burden, cost drivers, clinical outcomes and pharmacoeconomic studies. A key driver of the cost of Alzheimer's disease is the severity of the disease, indicating that the ability to stabilize the disease state is a potential source of cost savings. Drug therapies that can limit increases in behavioural problems and cognitive and functional impairment, and postpone institutionalization without an increase in longevity may serve to reduce the economic burden on Alzheimer's disease patients. The data suggest that, while the available, approved agents offer only modest improvements in clinical outcomes, they could be cost-effective treatments for moderate to severe Alzheimer's disease when viewed from the societal perspective. For memantine and donepezil, data are available that suggest that the cost of these drugs is offset by the clinical and societal benefits provided by slowing the progression of Alzheimer's disease. While there are few head-to-head comparison trials, the similarity in costs of the treatments and efficacy against placebo suggest that cost effectiveness will not be substantially different among treatments. More studies that examine longitudinal resource utilization and its relationship to drug treatment in the moderate to severe stages are needed to clarify cost benefit in this population and possibly differentiate between individual medications.

Advances in the treatment of psychiatric disorders in long-term care homes

PURPOSE OF REVIEW

Psychiatric disorders are common among older adults in long-term care (LTC) homes and the LTC population is rapidly growing in many countries. Treatment of psychiatric conditions in this population is challenging given the psychosocial environment and physical frailty of the population. This review highlights some important advances in pharmacological and nonpharmacological interventions in this setting.

RECENT FINDINGS

There is some evidence to support the use of psychosocial interventions for behavioral symptoms, including those utilizing sensory interventions such as aromatherapy and calming music; behavioral management techniques; cognitive stimulation; physical activity; and staff training. There is also some evidence to support the use of psychotherapies such as reminiscence therapy and cognitive behavior therapy for depression. Recent literature on the pharmacological management of behavioral symptoms of dementia have included studies of the antipsychotic aripiprazole, prazosin, and medication-discontinuation trials along with two negative studies involving melatonin and oxcarbazepine.

SUMMARY

The literature on psychosocial interventions for behavioral symptoms associated with dementia has been criticized for lack of vigor, but there is growing evidence from studies with improved methodology that these interventions may confer significant benefits, although the effect sizes are often small or moderate. More well designed trials of pharmacological therapies in the LTC population are also necessary.

Glutamate receptor ion channels: structure, regulation, and function

The mammalian ionotropic glutamate receptor family encodes 18 gene products that coassemble to form ligand-gated ion channels containing an agonist recognition site, a transmembrane ion permeation pathway, and gating elements that couple agonist-induced conformational changes to the opening or closing of the permeation pore. Glutamate receptors mediate fast excitatory synaptic transmission in the central nervous system and are localized on neuronal and non-neuronal cells. These receptors regulate a broad spectrum of processes in the brain, spinal cord, retina, and peripheral nervous system. Glutamate receptors are postulated to play important roles in numerous neurological diseases and have attracted intense scrutiny. The description of glutamate receptor structure, including its transmembrane elements, reveals a complex assembly of multiple semiautonomous extracellular domains linked to a pore-forming element with striking resemblance to an inverted potassium channel. In this review we discuss International Union of Basic and Clinical Pharmacology glutamate receptor nomenclature, structure, assembly, accessory subunits, interacting proteins, gene expression and translation, post-translational modifications, agonist and antagonist pharmacology, allosteric modulation, mechanisms of gating and permeation, roles in normal physiological function, as well as the potential therapeutic use of pharmacological agents acting at glutamate receptors.

Alzheimer's disease: clinical trials and drug development

Alzheimer's disease is the most common cause of dementia in elderly people. Research into Alzheimer's disease therapy has been at least partly successful in terms of developing symptomatic treatments, but has also had several failures in terms of developing disease-modifying therapies. These successes and failures have led to debate about the potential deficiencies in our understanding of the pathogenesis of Alzheimer's disease and potential pitfalls in diagnosis, choice of therapeutic targets, development of drug candidates, and design of clinical trials. Many clinical and experimental studies are ongoing, but we need to acknowledge that a single cure for Alzheimer's disease is unlikely to be found and that the approach to drug development for this disorder needs to be reconsidered. Preclinical research is constantly providing us with new information on pieces of the complex Alzheimer's disease puzzle, and an analysis of this information might reveal patterns of pharmacological interactions instead of single potential drug targets. Several promising randomised controlled trials are ongoing, and the increased collaboration between pharmaceutical companies, basic researchers, and clinical researchers has the potential to bring us closer to developing an optimum pharmaceutical approach for the treatment of Alzheimer's disease.

Management of behavioral problems in Alzheimer's disease

Alzheimer's disease (AD) is a complex progressive brain degenerative disorder that has effects on multiple cerebral systems. In addition to cognitive and functional decline, diverse behavioral changes manifest with increasing severity over time, presenting significant management challenges for caregivers and health care professionals. Almost all patients with AD are affected by neuropsychiatric symptoms at some point during their illness; in some cases, symptoms occur prior to diagnosis of the dementia syndrome. Further, behavioral factors have been identified, which may have their origins in particular neurobiological processes, and respond to particular management strategies. Improved clarification of causes, triggers, and presentation of neuropsychiatric symptoms will guide both research and clinical decision-making. Measurement of neuropsychiatric symptoms in AD is most commonly by means of the Neuropsychiatric Inventory; its utility and future development are discussed, as are the limitations and difficulties encountered when quantifying behavioral responses in clinical trials. Evidence from clinical trials of both non-pharmacological and pharmacological treatments, and from neurobiological studies, provides a range of management options that can be tailored to individual needs. We suggest that non-pharmacological interventions (including psychosocial/psychological counseling, interpersonal management and environmental management) should be attempted first, followed by the least harmful medication for the shortest time possible. Pharmacological treatment options, such as antipsychotics, antidepressants, anticonvulsants, cholinesterase inhibitors and memantine, need careful consideration of the benefits and limitations of each drug class.

Parkinson's psychosis

OPINION STATEMENT

Psychosis is a leading reason for nursing home placement of patients with Parkinson's disease (PD). It may also be the single greatest stressor for caregivers of PD patients, it is generally persistent, and its presence markedly increases the risk of mortality. For these reasons, it is essential to recognize and appropriately treat psychosis in PD. Treatment of psychotic symptoms should be initiated after potential medical and environmental causes of delirium (eg, infection) have been eliminated or addressed. Initial pharmacologic changes should include limiting the patient's anti-PD medications to those that are necessary to preserve motor function (ie, eliminating adjunctive agents). Should that fail, an atypical antipsychotic agent is the treatment of choice. Clozapine is presently the gold standard, and quetiapine represents another option because of its ease of use and good tolerability profile. Emerging treatment options include the use of acetylcholinesterase inhibitors, antidepressants, and cognitive behavioral therapy. This article reviews what is currently known about treatment strategies in PD psychosis.

Spotlight on memantine in moderate to severe Alzheimer's disease

Memantine (Axura, Ebixa, Namenda) is an uncompetitive, moderate-affinity NMDA receptor antagonist that is indicated for the treatment of moderate to severe Alzheimer's disease. In well designed trials in patients with moderate to severe Alzheimer's disease, oral memantine monotherapy improved outcomes in the area of functional ability more than placebo in one trial, but in a second trial, treatment differences did not reach significance. Memantine has a distinct mode of action compared with that of acetylcholinesterase (AChE) inhibitors, and in a well designed study, combination therapy with memantine plus donepezil improved outcomes more than donepezil plus placebo in all four domains (function, cognition, behaviour and global change). Memantine is generally well tolerated, with adverse events occurring with a similar incidence to that reported with placebo. In modelled cost-effectiveness analyses, memantine was dominant to no therapy in regard to cost per quality-adjusted life-year (QALY) gained, and the combination of memantine plus donepezil was dominant to donepezil therapy alone in regard to QALYs gained when treatment periods exceeded 1 year in patients with moderate to severe disease. Thus, in the management of patients with moderate to severe Alzheimer's disease, memantine provides an effective treatment option. To date, clinical trial support is greater for memantine use in combination with an AChE inhibitor, while more data are needed to confirm its efficacy as monotherapy.

Safety and tolerability of rivastigmine capsule with memantine in patients with probable Alzheimer's disease: a 26-week, open-label, prospective trial (Study ENA713B US32)

OBJECTIVE

Rivastigmine, a dual cholinesterase inhibitor (ChEI), is widely approved for the symptomatic treatment of both mild-to-moderate Alzheimer's disease (AD) and Parkinson's disease dementia. Orally administered ChEIs may be associated with gastrointestinal (GI) side effects and add-on therapy with memantine, an N-methyl-d-aspartate receptor antagonist, approved for moderate-to-severe AD, may ameliorate such side effects. This was a 26-week, prospective, multicenter, single-arm, open-label pilot study to assess the safety and tolerability of rivastigmine capsules plus memantine in patients with moderate AD.

METHODS

The primary objective was to assess the safety and tolerability of rivastigmine capsules 6-12 mg/day plus memantine (5-20 mg/day) as measured by the incidences of vomiting and nausea compared with those reported in the rivastigmine United States Prescribing Information (US PI). A total of 117 patients were enrolled with 116 receiving at least one dose of study medication.

RESULTS

The incidences of nausea and vomiting (30% and 13%, respectively) observed in patients who received 6-12 mg/day rivastigmine plus memantine were lower than those stated in the US PI for rivastigmine monotherapy 6-12 mg/day (47% and 31%, respectively). The most common adverse events were nausea, vomiting, and dizziness.

CONCLUSION

Results from this study suggest the combination of rivastigmine capsule and memantine in patients with moderate AD is safe and tolerable. A greater reduction in the GI tolerability of rivastigmine has been established with rivastigmine transdermal patch.

Meta-analyses: a method to maximise the evidence from clinical studies?

Evidence-based medicine (EBM) is becoming the guiding principle for clinical treatment decisions. But evidence remains a loosely defined term. Multiple criteria for evidence criteria have been proposed. Most influential evidence criteria give priority to meta-analyses because they promise an objective procedure to combine the outcomes of all informative, putatively conflicting studies on the same issue in an overall score. However, we claim that meta-analyses are of limited informative value for the following six reasons: (1) meta-analyses are often "overpowered" with clinically irrelevant results that might emerge as highly significant; (2) there is serious concern of publication biases with "negative" studies not being published; (3) meta-analyses consider the variation in the results of the empirical studies included to be random noise, however, the variability of results across studies can be informative; (4) the result of a meta-analysis depends on the strategy used to identify the included empirical studies; (5) the quality of conclusions from meta-analyses depends on the statistical tests used to combine the results of the separate studies; (6) the qualitative conclusions drawn from the meta-analytical combination of individual studies may depend on specific design aspects of the individual studies. Thus, meta-analyses are primarily a method to generate hypotheses through an a posteriori analysis of treatment effects.

Cost effectiveness of memantine in Alzheimer's disease in the UK

OBJECTIVE

This analysis assesses the cost-effectiveness of memantine for the treatment of moderate-to-severe Alzheimer's disease (AD) in the UK.

METHODS

This cost-utility analysis was based on a Markov model. The model simulated 5-year progress of patients with AD until they need full-time care (FTC), defined as a patient becoming either dependent or institutionalised. Transition probabilities were based on a predictive equation, derived from the London and South-East Region epidemiological study. Resource use, utilities and mortality were obtained from the same study. Memantine efficacy was based on a meta-analysis of six large trials. The model compared memantine to its alternative in the UK, i.e. no pharmacological treatment or background therapy with acetylcholinesterase inhibitors.

RESULTS

Memantine was found to delay the need to FTC by 6 weeks compared with current practice in the UK. It was associated with increased quality-adjusted life-years and cost savings to the healthcare system (probability of this outcome was 96%). The projections were made assuming that benefits from the 6-month treatment were sustained over time, which is regarded as the main limitation. The model underwent extensive sensitivity analyses, which confirmed the base-case findings.

CONCLUSIONS

The model suggests that memantine delays the need for FTC and decreases cost. It can be regarded as a cost-effective choice in the management of moderate and severe AD.

Memantine: a review of its use in moderate to severe Alzheimer's disease

Memantine is an uncompetitive, moderate-affinity NMDA receptor antagonist that is indicated for the treatment of moderate to severe Alzheimer's disease. In well designed trials in patients with moderate to severe Alzheimer's disease, oral memantine monotherapy improved outcomes in the area of functional ability more than placebo in one trial, but in a second trial, treatment differences did not reach significance. Memantine has a distinct mode of action compared with that of acetylcholinesterase (AChE) inhibitors, and in a well designed study, combination therapy with memantine plus donepezil improved outcomes more than donepezil plus placebo in all four domains (function, cognition, behaviour and global change). Memantine is generally well tolerated, with adverse events occurring with a similar incidence to that reported with placebo. In modelled cost-effectiveness analyses, memantine was dominant to no therapy in regard to cost per quality-adjusted life-year (QALY) gained, and the combination of memantine plus donepezil was dominant to donepezil therapy alone in regard to QALYs gained when treatment periods exceeded 1 year in patients with moderate to severe disease. Thus, in the management of patients with moderate to severe Alzheimer's disease, memantine provides an effective treatment option. To date, clinical trial support is greater for memantine use in combination with an AChE inhibitor, while more data are needed to confirm its efficacy as monotherapy.

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.

Effects of memantine on cognition in patients with moderate to severe Alzheimer's disease: post-hoc analyses of ADAS-cog and SIB total and single-item scores from six randomized, double-blind, placebo-controlled studies

OBJECTIVES

The post-hoc analyses reported here evaluate the specific effects of memantine treatment on ADAS-cog single-items or SIB subscales for patients with moderate to severe AD.

METHODS

Data from six multicentre, randomised, placebo-controlled, parallel-group, double-blind, 6-month studies were used as the basis for these post-hoc analyses. All patients with a Mini-Mental State Examination (MMSE) score of less than 20 were included. Analyses of patients with moderate AD (MMSE: 10-19), evaluated with the Alzheimer's disease Assessment Scale (ADAS-cog) and analyses of patients with moderate to severe AD (MMSE: 3-14), evaluated using the Severe Impairment Battery (SIB), were performed separately.

RESULTS

The mean change from baseline showed a significant benefit of memantine treatment on both the ADAS-cog (p < 0.01) and the SIB (p < 0.001) total score at study end. The ADAS-cog single-item analyses showed significant benefits of memantine treatment, compared to placebo, for mean change from baseline for commands (p < 0.001), ideational praxis (p < 0.05), orientation (p < 0.01), comprehension (p < 0.05), and remembering test instructions (p < 0.05) for observed cases (OC). The SIB subscale analyses showed significant benefits of memantine, compared to placebo, for mean change from baseline for language (p < 0.05), memory (p < 0.05), orientation (p < 0.01), praxis (p < 0.001), and visuospatial ability (p < 0.01) for OC.

CONCLUSION

Memantine shows significant benefits on overall cognitive abilities as well as on specific key cognitive domains for patients with moderate to severe AD.

Diagnosis and treatment of dementia: 6. Management of severe Alzheimer disease

BACKGROUND

The management of severe Alzheimer disease often presents difficult choices for clinicians and families. The disease is characterized by a need for full-time care and assistance with basic activities of daily living. We outline an evidence-based approach for these choices based on recommendations from the Third Canadian Consensus Conference on the Diagnosis and Treatment of Dementia.

METHODS

We developed evidence-based guidelines using systematic literature searches, with specific criteria for the selection and quality assessment of articles, and a clear and transparent decision-making process. We selected articles published from January 1996 to December 2005 that dealt with the management of severe Alzheimer disease. Subsequent to the conference, we searched for additional articles published from January 2006 to March 2008 using the same search terms. We graded the strength of the evidence using the criteria of the Canadian Task Force on Preventive Health Care.

RESULTS

We identified 940 articles, of which 838 were selected for further study. Thirty-four articles were judged to be of at least good or fair quality and were used to generate 17 recommendations. Assessment of severe Alzheimer disease should include the measurement of cognitive function and the assessment of behaviour, function, medical status, nutrition, safety and caregiver status. Management could include treatment with a cholinesterase inhibitor or memantine, or both. Treatment of neuropsychiatric symptoms begins with nonpharmacologic approaches to addressing behavioural problems. Severe agitation, aggression and psychosis, which are potentially dangerous to the patient, the caregiver and others in the environment, can be treated with atypical antipsychotics, with consideration of their increased risk of cerebrovascular events and death. All pharmacologic approaches require careful monitoring and periodic reassessment to determine whether continued treatment is necessary. Caregiver support and use of community resources are essential.

INTERPRETATION

Severe Alzheimer disease requires frequent monitoring by health professionals. Simple nonpharmacologic approaches may address problems with mood and agitation. Antipsychotic drug therapy is occasionally necessary despite the inherent risks. Therapy with a cholinesterase inhibitor and memantine may be useful for selected patients.

Pharmacological Treatment of Alzheimer's Disease: Is it Progressing Adequately?

INTRODUCTION

Between 1993 and 2000 four acetylcholinesterase inhibitors were marketed as a symptomatic treatment for Alzheimer's disease (AD), as well as memantine in 2003. Current research is focused on finding drugs that favorably modify the course of the disease. However, their entrance into the market does not seem to be imminent.

RESEARCH DEVELOPMENT

The aim of AD research is to find substances that inhibit certain elements of the AD pathogenic chain (beta- and gamma-secretase inhibitors, alpha-secretase stimulants, beta-amyloid aggregability reducers or disaggregation and elimination inductors, as well as tau-hyperphosphorylation, glutamate excitotoxicity, oxidative stress and mitochondrial damage reducers, among other action mechanisms). Demonstrating a disease's retarding effect demands longer trials than those necessary to ascertain symptomatic improvement. Besides, a high number of patients (thousands of them) is necessary, all of which turns out to be difficult and costly. Furthermore, it would be necessary to count on diagnosis and progression markers in the disease's pre-clinical stage, markers for specific phenotypes, as well as high-selectivity molecules acting only where necessary. In order to compensate these difficulties, drugs acting on several defects of the pathogenic chain or showing both symptomatic and neuroprotective action simultaneously are being researched.

CONCLUSIONS

There are multiple molecules used in research to modify AD progression. Although it turns out to be difficult to obtain drugs with sufficient efficacy so that their marketing is approved, if they were achieved they would lead to a reduction of AD prevalence.

Cognitive effects of memantine in postmenopausal women at risk of dementia: a pilot study

BACKGROUND

To determine the effects of memantine on cognition in a normal population of postmenopausal women with putative risk factors for Alzheimer's disease (AD) using a built-in control for the genetic risk factor for AD (apoE-epsilon4 status).

METHODS

A prospective, open-label, 6-month pilot medication trial with memantine and follow-up after discontinuance conducted at the Center for Neuroscience in Women's Health, Stanford University School of Medicine. Neuropsychological data were collected on 22 community-dwelling postmenopausal women (11 apoE-epsilon4 carriers and 11 apoE-epsilon4 non-carriers) with at least one putative risk factor for AD.

RESULTS

ApoE-epsilon4 status was not a significant predictor of change in neuropsychological performance. Changes associated with memantine treatment for entire sample included significant declines in some variables associated with verbal learning and memory that improved upon medication withdrawal. A positive medication effect was noted with executive functions and possibly category fluency. Trend-level improvements were seen in motor dexterity of the non-dominant hand and maintained even after drug discontinuance.

CONCLUSIONS

Treatment with memantine appeared to have differential effects on cognitive performance in a population of women with putative risk factors for AD. ApoE-epsilon4 carrier status did not account for observed changes in cognition.

Update on the use of memantine in Alzheimer's disease

Memantine is a low to moderate affinity N-methyl-D-aspartate receptor (NMDAR) antagonist. The effects of memantine in Alzheimer's disease (AD) have been studied in 7 randomized controlled trials in many post-hoc analyses. Three out of four RCTs in patients with moderate to severe AD (Mini Mental State Examination [MMSE] <14) showed a statistically significant but clinically small positive effect of memantine on cognition, global functioning, activities of daily living (ADL) and neuropsychiatric symptoms. No effects on these outcome measures could be found in the three RCTs studying patients with mild to moderate AD (MMSE 14-24). Two of these studies evaluated the effect of addition of memantine to donepezil. Only the study in patients with mild to moderate AD showed a positive effect of addition of memantine on cognition, ADL, global functioning and neuropsychiatric functioning. Cost-effectiveness of memantine therapy remains controversial. Post-hoc analyses and observational studies suggest some effects on agitation/aggression, delusions or hallucinations. Side effects of memantine are usually mild and seem to be comparable with placebo. In this review, an oversight of pharmacodynamics and pharmacokinetics of memantine is presented. Also, published data concerning efficacy and safety in patients with AD are presented.

Long-term course and effectiveness of combination therapy in Alzheimer disease

OBJECTIVE

To compare the real-world clinical effectiveness and long-term clinical trajectory in patients with Alzheimer disease (AD) treated with combination (COMBO) therapy consisting of cholinesterase-inhibitor (CI) plus memantine (MEM) versus CI alone versus no treatment with either.

METHODS

Three hundred eighty-two subjects with probable AD underwent serial clinical evaluations at a memory disorders unit. Cognition was assessed by the Information-Memory-Concentration subscale of the Blessed Dementia Scale (BDS) and function was assessed by the Weintraub Activities of Daily Living Scale (ADL) at 6-month intervals. One hundred forty-four subjects received standard care without CI or MEM (NO-RX), 122 received CI monotherapy, and 116 received COMBO therapy with CI plus MEM. Mean follow-up was 30 months (4.1 visits) and mean cumulative medication treatment time was 22.5 months. Rates of decline were analyzed using mixed-effects regression models, and Cohen's d effect sizes were calculated annually for years 1 to 4.

RESULTS

Covarying for baseline scores, age, education, and duration of illness, the COMBO group had significantly lower mean annualized rates of deterioration in BDS and ADL scores compared with the CI (P<0.001; Cohen's dBDS=0.10-0.34 and dADL=0.23-0.46 at 1 to 2 y) and NO-RX groups (P<0.001; Cohen's dBDS=0.56-0.73 and dADL=0.32-0.48 at 1 to 2 y). For the COMBO group, Cohen's d effect sizes increased with treatment duration. Similar comparisons significantly favored the CI over the NO-RX group on the BDS.

CONCLUSIONS

COMBO therapy slows cognitive and functional decline in AD compared with CI monotherapy and no treatment. These benefits had small-to-medium effect sizes that increased with time on treatment and were sustained for years.

Pharmacological treatment of Alzheimer's dementia: state of the art and current dilemmas

Alzheimer's disease (AD) is one of the most frequent disorders of the central nervous system characterised by a progressive cognitive decline. The demographic changes of our aging population lead to increased numbers of patients and a need of early diagnosis and treatment of cognitive and behavioural symptoms of AD. Drugs are available for symptomatic treatment of AD. The pharmacological treatment of behavioural disturbances experienced dynamic changes in the last years. In this paper, we present the current state and future perspectives in the treatment of AD. Furthermore, we discuss current difficulties regarding AD treatment by looking for explanations for a still unsatisfying rate of state-of-the-art treatment of AD-patients.

Course, prognosis, and management of psychosis in Parkinson's disease: are current treatments really effective?

It is essential to recognize and treat psychosis in Parkinson's disease for several reasons. Studies have shown that psychosis in Parkinson's disease patients is a strong risk factor for nursing home placement. Psychosis may be the greatest source of stress for caretakers of Parkinson's patients; it is often persistent, and its presence markedly increases mortality. Treatment of psychotic symptoms should occur only after potential medical and environmental causes of delirium have been eliminated or addressed. Initial pharmacologic changes should include limiting the patient's antiparkinsonian medications to those that are necessary to preserve motor function. Should that fail, an atypical antipsychotic is presently the treatment of choice. An emerging treatment option is acetylcholinesterase inhibitors. This article reviews what is currently known about the course, prognosis, and treatment strategies in Parkinson's disease psychosis.

Prevention therapeutics of dementia

In the absence of effective drugs for Alzheimer's disease (AD) and a validated roadmap or guideline for drug development, it is important to consider some of the limitations currently hampering AD drug development and some general principles for moving forward. This paper will address current barriers to developing drugs for AD, and offer new considerations for accelerating drug discovery, development, and clinical trials.