Memantine treatment in patients with moderate to severe Alzheimer disease already receiving donepezil: a randomized controlled trial

A randomized trial of the impact of a specific care plan in 1120 Alzheimer's patients (PLASA Study) over a two-year period: design and baseline data

OBJECTIVE

To describe the design anf baseline patient characteristics of a multicomponent specific care and assistance plan (PLASA) study in Alzheimer's Disease (AD). The study is designed to evaluate the effect of PLASA in AD primarily looking at change in functional capacity.

DESIGN

Two-years prospective cluster randomized controlled trial comparing PLASA and usual care.

SETTING

Forty-nine hospitals in France.

PARTICIPANTS

1120 community-dwelling AD.

INTERVENTION

Patients in the intervention group are evaluated biannually using a standardized comprehensive global assessment. In the case of decline in any one domain a standardized study protocol recommends specific physician directed intervention in addition to information and training for the caregiver.

MEASUREMENTS

Alzheimer Disease Cooperative Study-Activities of Daily Living scale, Resource Utilization in Dementia scale, Clinical Global Impression of Change.

RESULTS

At baseline, the two groups were similar regarding patient and caregiver characteristics. The mean patient age was 79.61+5.72 years and the mean MMSE 19.73+4.01 for the whole cohort. Time since dementia diagnosis was about 1.37+1.65 years in the whole cohort. Almost a third of the patients lived alone at baseline. Mean monthly time spent in caregiving in the whole cohort was 52.70+71.83 hours for instrumental activities and 17.73+51.38 hours for basic activities.

CONCLUSION

Persons with dementia suffer different losses at different stages of the disease and therefore accurate assessment of abilities and losses is critical to assist the person in planning for their future and for care needs. The PLASA intervention study is ongoing with 2 year follow-up to be completed in 2007.

Management of the behavioral and psychological symptoms of dementia

More than 50% of people with dementia experience behavioral and psychological symptoms of dementia (BPSD). BPSD are distressing for patients and their caregivers, and are often the reason for placement into residential care. The development of BPSD is associated with a more rapid rate of cognitive decline, greater impairment in activities of daily living, and diminished quality of life (QOL). Evaluation of BPSD includes a thorough diagnostic investigation, consideration of the etiology of the dementia, and the exclusion of other causes, such as drug-induced delirium, pain, or infection. Care of patients with BPSD involves psychosocial treatments for both the patient and family. BPSD may respond to those environmental and psychosocial interventions, however, drug therapy is often required for more severe presentations. There are multiple classes of drugs used for BPSD, including antipsychotics, anticonvulsants, antidepressants, anxiolytics, cholinesterase inhibitors and NMDA modulators, but the evidence base for pharmacological management is poor, there is no clear standard of care, and treatment is often based on local pharmacotherapy customs. Clinicians should discuss the potential risks and benefits of treatment with patients and their surrogate decision makers, and must ensure a balance between side effects and tolerability compared with clinical benefit and QOL.

Disease-modifying therapies in Alzheimer's disease

Alzheimer's disease (AD) is a chronic, progressive, neurodegenerative disorder that places a substantial burden on patients, their families, and society. The disease affects approximately 5 million individuals in the United States, with an annual cost of care greater than $100 billion. During the past dozen years, several agents have been approved that enhance cognition and global function of AD patients, and recent advances in understanding AD pathogenesis has led to the development of numerous compounds that might modify the disease process. A wide array of antiamyloid and neuroprotective therapeutic approaches are under investigation on the basis of the hypothesis that amyloid beta (A beta) protein plays a pivotal role in disease onset and progression and that secondary consequences of A beta generation and deposition, including tau hyperphosphorylation and neurofibrillary tangle formation, oxidation, inflammation, and excitotoxicity, contribute to the disease process. Interventions in these processes with agents that reduce amyloid production, limit aggregation, or increase removal might block the cascade of events comprising AD pathogenesis. Reducing tau hyperphosphorylation, limiting oxidation and excitotoxicity, and controlling inflammation might be beneficial disease-modifying strategies. Potentially neuroprotective and restorative treatments such as neurotrophins, neurotrophic factor enhancers, and stem cell-related approaches are also under investigation.

Alzheimer's disease

Alzheimer's disease is the most prevalent form of dementia. There are significant efforts underway to elucidate the pathogenesis of this disease and to find ways to lessen the impact of the symptoms. This paper summarizes current knowledge regarding the diagnosis and treatment of the disorder.

Effects of memantine on mitochondrial function

Because NMDA complex and mitochondrial function are related, we hypothesized memantine would influence mitochondrial function. We addressed this in vitro by studying the effects of chronic and acute memantine exposures on mitochondrial function. For acute exposure experiments, mitochondria were isolated from NT2 cells and assayed for electron transport chain (ETC) enzyme function and peroxide production in buffers containing up to 60uM memantine. For chronic exposure experiments, NT2 cells were maintained for at least two weeks in medium containing up to 60uM memantine, following which we assayed cells or their mitochondria for ETC enzyme activities, cytochrome oxidase protein levels, oxidative stress, calcium levels, and mitochondrial DNA levels. The ability of the NMDA receptor antagonist aminophosphonovaleric acid (APV) to modify memantine's mitochondrial effects was evaluated. Acute and chronic memantine similarly affected complex I (increased at high concentrations) and IV (decreased at high concentrations) V(max) activities. APV did not alter the effects of chronic memantine exposure on citrate synthase and complex IV. We detected a lower mitochondrial peroxide production rate with acute exposure, and an increased mitochondrial peroxide production rate with chronic exposure. Micromolar memantine concentrations affect mitochondria, some of these effects are directly mediated, and acute and chronic effects may differ.

State of confusion: sorting out a complex medication regimen for a 79-year-old woman

Patients with Alzheimer's disease and without caregiver assistance can often have difficulties in managing their medications, which can result in serious consequences. This case study depicts a 79-year-old woman who lives in an assisted living facility and is referred to a geriatric pharmacy specialist in a community pharmacy for a medication review and assistance in medication adherence. During the initial patient visit, the patient was found to have an extremely complex method for managing her medications. She also had multiple medical providers, several duplicate medications, and medications used to treat the adverse effects of other medications. Consequently, this patient had symptoms suggesting she was experiencing medication-induced delirium. This case study illustrates the valuable role of the consultant pharmacist in assisting the patient's medical providers in formulating a simpler and more efficacious medication regimen.

The use of cognitive enhancers in behavioral disturbances of Alzheimer's disease

OBJECTIVE

To review the literature for double-blind, placebo-controlled trials that examined the efficacy of cognitive enhancers in the psychopathology of Alzheimer's disease.

DATA SOURCES

Literature searches were conducted using MEDLINE and EMBASE databases and clinicaltrials.gov.

STUDY SELECTION

Overall, 55 articles were reviewed for inclusion. Several open-label studies and case reports were found on this topic, but only those involving both tacrine and use of the Neuropsychiatric Inventory were included. Regarding other drugs, only double-blind, placebo-controlled trials were selected for inclusion.

DATA SYNTHESIS

Limited data suggest that the anticholinesterase inhibitors and memantine offer an alternative or adjunct to the antipsychotics for the treatment of moderate-to-severe behaviors. The author reviewed the literature for pharmacological management of behavioral and psychological symptoms of dementia (BPSD) using these cognitive enhancers.

CONCLUSION

The majority of patients with Alzheimer's disease will experience behavioral disturbances during the course of their disease. Atypical antipsychotics are used routinely in these situations to treat the psychotic features and agitation. However, atypicals now carry a "black box" warning issued by the Food and Drug Administration on the basis of evidence that their use in geriatric patients with dementia-related psychosis may put patients at increased risk of mortality as a result of cardiovascular or infectious events. An alternative to the atypicals may be the acetylcholinesterase inhibitors and memantine, which have been shown to stabilize cognitive as well as behavioral issues in patients, utilizing the "gold standard" for behavior, the Neuropsychiatric Inventory. Efficacy varies among agents, with the greatest positive effects seen with donepezil, which also has the greatest number of studies. Drug benefits were harder to demonstrate for mild-to-moderate BPSD compared with moderate-to-severe symptoms.

Donepezil markedly potentiates memantine neurotoxicity in the adult rat brain

The NMDA antagonist, memantine (Namenda), and the cholinesterase inhibitor, donepezil (Aricept), are currently being used widely, either individually or in combination, for treatment of Alzheimer's disease (AD). NMDA antagonists have both neuroprotective and neurotoxic properties; the latter is augmented by drugs, such as pilocarpine, that increase cholinergic activity. Whether donepezil, by increasing cholinergic activity, might augment memantine's neurotoxic potential has not been investigated. In the present study, we determined that a dose of memantine (20mg/kg, i.p.), considered to be in the therapeutic (neuroprotective) range for rats, causes a mild neurotoxic reaction in the adult rat brain. Co-administration of memantine (20 or 30 mg/kg) with donepezil (2.5-10mg/kg) markedly potentiated this neurotoxic reaction, causing neuronal injury at lower doses of memantine, and causing the toxic reaction to become disseminated and lethal to neurons throughout many brain regions. These findings raise questions about using this drug combination in AD, especially in the absence of evidence that the combination is beneficial, or that either drug arrests or reverses the disease process.

A randomised double-blind placebo-controlled trial of folic acid supplementation of cholinesterase inhibitors in Alzheimer's disease

OBJECTIVES

(1) to assess the effect of 1 mg folic acid supplementation of cholinesterase inhibitors (ChI) in a 6 month double-blind placebo-controlled study of patients with Alzheimer's Disease (AD) and (2) to assess whether outcome measures were affected by changes in homocysteine levels.

METHOD

Fifty-seven consecutive outpatients with probable AD were treated concurrently with a ChI and either folic acid or placebo. None had conditions or medication known to interfere with folate metabolism. Fasting folate and homocysteine levels were measured prior to commencing ChI and 6 months later. Response was categorised using criteria of the National Institute of Clinical Excellence (NICE).

RESULTS

Twelve males and 29 females completed treatment (mean age 76.27 SD 6.23 years, Mini-Mental State Examination (MMSE) 23.49 SD 3.53, baseline homocysteine 18.39 SD 4.62 micromoles per litre). 23 received folic acid and 18 placebo. There were no significant baseline differences or use of individual ChI between the two arms. After 6 months a significant difference was seen in the change from baseline in combined Instrumental Activities of Daily Living and Social Behaviour scores between arms (folate+1.50 (SD 5.32) vs placebo -2.29 (SD 6.16) (p=0.03) but not change in MMSE scores. Sixteen of 23 subjects receiving folic acid and 7/18 placebo subjects were classified as NICE responders (p=0.05).

CONCLUSION

This pilot double blind study suggests that response to ChI in patients with AD may be improved by the use of folic acid. The relationship between any change in homocysteine levels and response to treatment is discussed.

Addition of memantine to antipsychotic treatment in schizophrenia inpatients with residual symptoms: A preliminary study

BACKGROUND

Schizophrenia is comprised of several debilitating symptoms. Antipsychotics offer an effective treatment for positive symptoms, while the negative signs and cognitive deficits are usually treatment-resistant. It was suggested that glutamate dysregulation may be involved in the neuropathology of schizophrenia, mainly through NMDA dysfunction. We hypothesized that addition of memantine, a weak non-selective NMDA receptor antagonist approved for dementia, to antipsychotics would improve the clinical status of un-remitted schizophrenia patients, notably the negative signs and cognitive deficits.

METHODS

Seven schizophrenia patients, were included in a six-week open-label study, with weekly increasing dosage (5, 10, 15, 20 mg) of memantine added to their on-going antipsychotic treatment.

RESULTS

We found a significant improvement of the PANSS score (baseline 116.28+/-21.9 vs. 97.86+/-24.48 after six weeks, t=5.98, p<0.001) with the most prominent improvement (21%) in negative signs sub-scale (baseline 40+/-6.38 vs. 31.71+/-7.76 after six weeks, t=5.87, p<0.001). Cognitive status, measured with the Neurobehavioral Cognitive Examination (NCSE) and Clock Drawing Test (CDT) showed no improvement.

CONCLUSION

Memantine addition to antipsychotic treatment, in schizophrenia patients might improve their clinical status, primarily the negative signs, but not their cognitive deficits. Further research is needed to replicate these observations.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

Efficacy of memantine on behavioral and psychological symptoms related to dementia: a systematic meta-analysis

BACKGROUND

The behavioral and psychological symptoms related to dementia (BPSD) are difficult to manage and are associated with adverse patient outcomes.

OBJECTIVE

To systematically analyze the data on memantine in the treatment of BPSD.

METHODS

We searched MEDLINE, EMBASE, Pharm-line, the Cochrane Centre Collaboration, www.clinicaltrials.gov, www.controlled-trials.com, and PsycINFO (1966-July 2007). We contacted manufacturers and scrutinized the reference sections of articles identified in our search for further references, including conference proceedings. Two researchers (IM and CF) independently reviewed all studies identified by the search strategy. We included 6 randomized, parallel-group, double-blind studies that rated BPSD with the Neuropsychiatric Inventory (NPI) in our meta-analysis. Patients had probable Alzheimer's disease and received treatment with memantine for at least one month. Overall efficacy of memantine on the NPI was established with a t-test for the average difference between means across studies, using a random effects model.

RESULTS

Five of the 6 studies identified had NPI outcome data. In these 5 studies, 868 patients were treated with memantine and 882 patients were treated with placebo. Patients on memantine improved by 1.99 on the NPI scale (95% Cl -0.08 to -3.91; p = 0.041) compared with the placebo group.

CONCLUSIONS

Initial data appear to indicate that memantine decreases NPI scores and may have a role in managing BPSD. However, there are a number of limitations with the current data; the effect size was relatively small, and whether memantine produces significant clinical benefit is not clear.

The uncompetitive N-methyl-D-aspartate (NMDA) receptor antagonist memantine prolongs spatial memory in a rat delayed radial-arm maze memory task

In the present study, we evaluated the effects of memantine in a delayed radial-arm maze rat task, consisting of an acquisition phase followed 18 h later by a win-shift retrieval test. When administered 20 min before acquisition, memantine elicited an inverted U-shape dose-response relationship, with low doses (0.3 and 0.56 mg/kg) reducing the number of errors committed during the retrieval test, while high doses (3 and 10 mg/kg) disrupted maze running. Memantine given immediately after acquisition or 20 min before retrieval failed to affect performance. Co-administration of subthreshold doses of memantine with either the CB(1) receptor antagonist rimonabant or the acetylcholine esterase inhibitor donepezil failed to enhance performance. Thus, low doses of memantine enhance acquisition processes that lead to prolonged spatial memory.

Memory for the September 11, 2001, terrorist attacks one year later in patients with Alzheimer's disease, patients with mild cognitive impairment, and healthy older adults

Although there are many opportunities to study memory in patients with Alzheimer's disease (AD) in the laboratory, there are few opportunities to study memory for real world events in these patients. The September 11, 2001 terrorist attacks provided one such opportunity. Patients with AD, patients with mild cognitive impairment (MCI), and healthy older adults were given a telephone questionnaire in the initial weeks after the event, again three to four months later, and finally one year afterwards to evaluate their memory for the September 11, 2001 terrorist attacks. We were particularly interested in using the attacks as an opportunity to examine the decline of episodic memory in patients with AD, patients with MCI, and older adult controls over a period of months. We found that compared to healthy older adults, patients with AD and MCI showed impaired memory at the initial time point, more rapid forgetting from the initial to the three-month time point, and very similar changes in memory from the three-month to the one-year time point. We speculated that these findings were consistent with patients with AD and MCI showing initial impaired encoding and a more rapid rate of forgetting compared with healthy older adults, but that once the memories had been consolidated, their decay rate became similar to that of healthy older adults. Lastly, although memory distortions were common among all groups, they were greatest in the patients with AD.

Memantine (Ebixa) in clinical practice - results of an observational study

BACKGROUND/AIMS

In a post-marketing observational study, the efficacy and tolerability of memantine were examined in patients with moderate to severe Alzheimer's disease.

METHODS

The patients were treated with 20 mg/day of memantine for a 6-month period. The efficacy of memantine was evaluated using the Mini-Mental State Examination, the Nurses' Observation Scale for Geriatric Patients (NOSGER) and the Explorationsmodul Demenz (EMD) scale. In addition, a global assessment was made by the physician.

RESULTS

After 6 months of open-label treatment with memantine, the patients' cognitive function, ability to perform daily activities and global performance all showed a marked improvement. In the overall evaluation by the physician, improvement or stabilisation had been achieved by 78.8% of patients after 6 months of therapy. Memantine also demonstrated an excellent tolerability profile.

CONCLUSION

The results of this naturalistic study support the significant efficacy and tolerability of memantine that has been previously demonstrated in randomised, controlled clinical Alzheimer's disease trials.

Analysis of the effect of memantine in reducing the worsening of clinical symptoms in patients with moderate to severe Alzheimer's disease

BACKGROUND

Alzheimer's disease (AD) is a progressive neurodegenerative disorder and delaying disease worsening is a relevant treatment outcome.

METHODS

Data from 6 randomized, double-blind, placebo-controlled, 6-month studies were pooled and a subgroup of patients (867 on placebo, 959 on memantine) with moderate to severe AD (Mini- Mental State Examination <20) was analyzed. 'Any clinical worsening' was defined as a decline on the Alzheimer's Disease Assessment Scale - Cognitive Subscale (ADAS-cog) or the Severe Impairment Battery (SIB) and on the Clinician's Interview-Based Impression of Change Plus Caregiver Input (CIBIC-plus) and the Alzheimer's Disease Cooperative Study - Activities of Daily Living Inventory (ADCS-ADL), and 'marked clinical worsening' as > or = 4 points decline on the ADAS-cog or > or = 5 points on the SIB and decline on the CIBIC-plus and the ADCS-ADL.

RESULTS

More placebo-treated than memantine-treated patients showed any clinical worsening (28 vs. 18%; p < 0.001), and 21% placebo-treated patients compared to 11% memantine-treated patients had marked clinical worsening (p < 0.001).

CONCLUSION

In this population of moderate and severe AD patients, treatment with memantine was associated with reducing worsening of clinical symptoms in AD during the 6-month study period.

SK-PC-B70M from Pulsatilla koreana improves scopolamine-induced impairments of memory consolidation and spatial working memory

Previous studies have shown that hederacolchiside-E from Pulsatilla koreana has neuroprotective effects and cognition-enhancing effects. Subsequently, in the current study, we demonstrate that oral administrations of oleanolic-glycoside saponins enriched fraction from P. koreana, designated as SK-PC-B70M, improve impairments in memory consolidation and spatial working memory by systemic injection of scopolamine, a muscarinic cholinergic receptor antagonist. In a step-through avoidance task, when the rats stepped through a dark chamber in a shuttle box, an electric shock was given and then SK-PC-B70M was administered 30 min later. Twenty-four hours later, the rats were placed in an illuminated chamber. The rats with SK-PC-B70M treatments showed longer response latencies than rats with only scopolamine. Spatial working memory was measured with a trial-unique matching-to-place task in a water maze which assessed memory for place information over varying lengths of delays. Three delay lengths were used: 1 min, 5 min, and 3 h. In comparison with the control rats, the rats with scopolamine treatments took significantly longer to find the platform in the second trial with 1- and 5-min delays. The rats with both scopolamine and SK-PC-B70M had significantly less search error compared with the rats with scopolamine only. These findings indicate that SK-PC-B70M has effects on reversing impairments of memory consolidation and working memory impairments induced by scopolamine.

Calcium dysregulation in Alzheimer's disease

Alzheimer disease (AD) is the most common form of adult dementia. Its pathological hallmarks are synaptic degeneration, deposition of amyloid plaques and neurofibrillary tangles, leading to neuronal loss. A few hypotheses have been proposed to explain AD pathogenesis. The beta-amyloid (Abeta) and hyperphosphorylated tau hypotheses suggest that these proteins are the main players in AD development. Another hypothesis proposes that the dysregulation of calcium homeostasis may be a key factor in accelerating other pathological changes. Although Abeta and tau have been extensively studied, recently published data provide a growing body of evidence supporting the critical role of calcium signalling in AD. For example, presenilins, which are mutated in familial cases of AD, were demonstrated to form low conductance calcium channels in the ER and elevated cytosolic calcium concentration increases amyloid generation. Moreover, memantine, an antagonist of the NMDA-calcium channel receptor, has been found to have a beneficial effect for AD patients offering novel possibilities for a calcium signalling targeted therapy of AD. This review underscores the growing importance of calcium ions in AD development and focuses on the relevant aspects of calcium homeostasis.

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

The efficacy of memantine in Alzheimer's disease (AD) has been investigated in multiple randomised, placebo-controlled phase III trials. Recently, the indication label for memantine in Europe was extended to cover patients with moderate to severe AD, i.e. Mini-Mental State Exam total scores below 20. The efficacy data for memantine in this patient subgroup has been summarised by a meta-analysis of 1,826 patients in six trials. Efficacy was assessed using measures of global status (Clinician's Interview-Based Impression of Change Plus Caregiver Input), cognition (Alzheimer's Disease Assessment Scale - Cognitive Subscale, or Severe Impairment Battery), function (Alzheimer's Disease Cooperative Study Activities of Daily Living 19- or 23-item scale), and behaviour (Neuropsychiatric Inventory). Results (without replacement of missing values) showed statistically significant effects for memantine (vs. placebo) in each domain. Memantine was well tolerated, and the overall incidence rates of adverse events were comparable to placebo. This meta-analysis supports memantine's clinically relevant efficacy in patients with moderate to severe AD.

Pharmacotherapy of Alzheimer disease

OBJECTIVE

To systematically review published clinical trials of the pharmacotherapy of Alzheimer disease (AD).

METHOD

We searched MEDLINE for published English-language medical literature, using Alzheimer disease and treatment as key words. No other search engine was used. Our review focused on randomized clinical trials (RCTs) and corresponding metaanalyses.

RESULTS

Although there are many RCTs for the treatment of mild cognitive impairment (MCI), none have been successful in their primary analysis. The cholinesterase inhibitors donepezil, rivastigmine, and galantamine have demonstrated efficacy in 3- to 12-month placebo-controlled RCTs assessing cognitive, functional, behavioural, and global outcomes in patients with mildly to moderately severe AD. Recent data from patients with severe stages of AD demonstrate the efficacy of donepezil on cognitive and functional measures but not on behaviour. The N-methyl-D-aspartate receptor antagonist memantine has been demonstrated to be effective in 6-month, placebo-controlled RCTs of 6 months duration assessing cognitive, functional, and global outcomes of inpatients with moderate-to-severe AD (defined as a Mini Mental State Examination score below 20). Post hoc analyses have demonstrated a benefit in regard to agitation and (or) aggression, but this needs to be confirmed in a prospective RCT across Canada. Disease-modifying treatments are being tested in mild stages of AD in 18-month RCTs with cognitive and global outcomes as primary efficacy outcomes, primarily with drugs reducing amyloid synthesis or aggregation. Successful treatment in mild stages of AD could lead to RCTs in MCI and, possibly, in genetically high-risk asymptomatic individuals.

CONCLUSION

The significant advances in the symptomatic pharmacotherapy of AD may be followed by disease-modification treatments.

Memantine reduces neuronal dysfunctions triggered by in vitro ischemia and 3-nitropropionic acid

Memantine, a low-affinity uncompetitive NMDA receptor antagonist, has been widely utilized for the treatment of Alzheimer's disease. A possible neuroprotective role of this drug in pathophysiological conditions involving an altered energetic metabolism of the basal ganglia has never been addressed. Thus, we have characterized the electrophysiological effect of memantine on striatal spiny neurons recorded under control conditions and after in vitro ischemia (oxygen and glucose deprivation). Memantine reduced in a dose-dependent manner (EC(50)=5 microM) the irreversible loss of field potential amplitude induced by in vitro ischemia. The neuroprotective effect of memantine against in vitro ischemia was even more potent (EC(50)=3.2 microM) in the absence of external magnesium, a condition enhancing NMDA-mediated glutamatergic transmission. Memantine was also able to block long-term potentiation recorded from spiny neurons following a brief ischemic episode. Moreover, memantine showed protection against irreversible field potential loss induced by 3-nitropropionic acid (3-NP), an inhibitor of the mitochondrial complex II, without influencing toxicity induced by rotenone, a complex I inhibitor. Memantine could represent a potential neuroprotective agent in pathophysiological conditions involving an altered energy metabolism of basal ganglia.

Prise en charge de la maladie d'Alzheimer

Management of Alzheimer disease is based on drug and nondrug treatments. Specific drug treatment includes acetylcholinesterase inhibitors and memantine. They show moderate efficacy superior to that of placebo for global condition, cognitive disorders, need for care, and behavioral problems, but do not prevent further decline. These treatments remain underused. The efficacy of psychotropic drugs (antidepressants, neuroleptics, and antipsychotic agents) in treating behavioral problems is not well documented. Nondrug activities and interventions have not been sufficiently evaluated scientifically. These involve interventions against the consequences of the disease (loss of autonomy, malnutrition) and helping patients' family caregivers. Among these activities, the best evaluated and most interesting are: educational programs for caregivers, occupational therapy at home, and interventions at home by nurses specially trained as case managers.

Pharmacologic management of neuropsychiatric symptoms of Alzheimer disease

OBJECTIVE

To systematically review published clinical trials of the pharmacotherapy of neuropsychiatric symptoms of Alzheimer disease (AD).

METHOD

We searched MEDLINE and EMBASE for published English-language medical literature. Our review focused on randomized controlled trials (RCTs) and corresponding metaanalyses.

RESULTS

The pharmacotherapy of neuropsychiatric symptoms of AD has been studied with numerous RCTs. The largest number of studies has focused on antipsychotics. Data are of reasonably high quality and indicate that risperidone and olanzapine are more effective than placebo for institutionalized patients with severe agitation, aggression, and psychosis. The efficacy of antipsychotics is counterbalanced by safety concerns that include cerebrovascular adverse events and mortality. Cholinesterase inhibitors and memantine appear to have modest benefits for patients with mildly to moderately severe symptoms. Antidepressants are effective for treating depression in AD, but more data are required to determine the efficacy of trazodone and citalopram for agitation and aggression. Carbamazepine appears to be efficacious, although side effects and concerns about drug-drug interactions limit its use. The data do not support the use of valproate. Benzodiazepines should only be used for short-term, as-needed use. There are insufficient data on other pharmacologic interventions, such as beta blockers, buspirone, and estrogen preparations.

CONCLUSIONS

Although there have been numerous well-designed studies of the pharmacotherapy of neuropsychiatric symptoms in AD, safer and more effective treatments are urgently needed.

Memantine and HIV-associated cognitive impairment: a neuropsychological and proton magnetic resonance spectroscopy study

OBJECTIVE

To assess the safety and efficacy of memantine, an uncompetitive antagonist of the N-methyl-D-aspartate receptor as treatment of HIV-associated cognitive impairment.

METHODS

This was a Phase II randomized, double-blind, placebo-controlled, multicenter trial within the Adult AIDS Clinical Trials Group. One-hundred and forty HIV-infected adults with mild to severe AIDS dementia complex receiving stable antiretroviral therapy were enrolled. Memantine was initiated at 10 mg daily escalated to 40 mg daily, or up to the maximum tolerated dose and continued for 16 weeks (primary evaluation visit) followed by a 4-week washout period and re-evaluation at week 20. Changes in cognitive performance were measured as percent change from baseline to week 16 in the average of eight neuropsychological test scores (NPZ-8). Brain metabolism was measured by magnetic resonance spectroscopy in a subgroup of subjects.

RESULTS

Sixty-one percent of subjects in the memantine group and 85% in the placebo group reached the 40 mg dose while the reported adverse experiences between the two groups were similar. There were no significant improvements in neuropsychological performance over 16 weeks; however, memantine was associated with a significant increase at week 16 in the N-acetyl aspartate to creatine ratio, in the frontal white matter (P = 0.040) and parietal cortex (P = 0.023).

CONCLUSIONS

Memantine was safe and tolerated by HIV-infected subjects with cognitive impairment. Although we observed no significant differences in cognitive performance, the magnetic resonance spectroscopy data suggest that memantine may ameliorate neuronal metabolism, an important step to stabilizing or preventing neuronal injury. These results underscore the need for longer studies to assess the full potential of neuroprotective agents.

Agonist concentration dependency of blocking kinetics but not equilibrium block of N-methyl-d-aspartate receptors by memantine

Memantine is an uncompetitive N-methyl-D-aspartate (NMDA) receptor antagonist which is registered in both Europe and the USA for the treatment of Alzheimer's disease (AD). Cultured rat hippocampal neurons were used to evaluate the potency and blocking kinetics of this therapeutically very well-tolerated agent in the presence of various concentrations of the synthetic agonist NMDA and a constant, saturating concentration of the co-agonist D-serine (10 microM). Whole-cell patch-clamp experiments at -70 mV revealed that the degree of "equilibrium" blockade of NMDA-induced currents by memantine was largely unaffected by the concentration of the agonist NMDA. The IC50 values for NMDA at 300, 100, 30 and 10 microM were 0.80+/-0.12, 1.01+/-0.08, 0.92+/-0.13 and 1.31+/-0.09 microM, respectively, giving an average IC(50) for all agonists concentrations tested of 1.01+/-0.11 microM. In contrast, and as expected, the onset and offset kinetics of blockade were clearly dependent on agonist concentration. For NMDA 300, 100, 30 and 10 microM, kon values were 10.55+/-1.41, 8.60+/-0.17, 4.90+/-0.20 and 3.22+/-0.08x10(4) M(-1) s(-1), respectively; 1/tauon values at the IC50 concentration of memantine-i.e. 1 microM-were 0.58+/-0.11, 0.28+/-0.05, 0.15+/-0.02 and 0.11+/-0.03 s(-1), respectively and koff values were 0.24+/-0.01, 0.19+/-0.01, 0.14+/-0.00 and 0.09+/-0.01 s(-1), respectively. It therefore appears that the kinetics, but not the equilibrium potency, of memantine are agonist concentration-dependent. These fast agonist concentration-dependent kinetic properties, in addition to the clear voltage-dependence of memantine, are proposed to be important for the therapeutic tolerability of this compound in the treatment of AD.

A novel class of amino-alkylcyclohexanes as uncompetitive, fast, voltage-dependent, N-methyl-D-aspartate (NMDA) receptor antagonists--in vitro characterization

The fact that potent NMDA receptor channel blockers produce phencyclidine-like psychotropic symptoms in man and rodents implies that uncompetitive antagonism of NMDA receptors may not be a promising therapeutic approach. However, recent data indicate that agents with moderate affinity such as memantine and neramexane (MRZ 2/579) are useful therapeutics due to their strong voltage-dependency and rapid unblocking kinetics. Merz has developed a series of novel uncompetitive NMDA receptor antagonists based on an amino-alkylcyclohexane structure. These compounds displaced [(3)H]-MK-801 binding to rat cortical membranes with K(i) values between 1 and 100 microM and inward current responses of cultured hippocampal neurons to NMDA were antagonized in a strongly voltage-dependent manner with rapid blocking/unblocking kinetics. Three of these compounds, with similar biophysical properties to memantine, were chosen for development. MRZ 2/759 (1-ethenyl-3,3,5,5-tetramethyl-cyclohexylamine), 2/1010 (1,3,3,5-tetramethyl-6-azabicyclo[3.2.1]octane) and 2/1013 (8,8,10,10-tetramethyl-1-azaspiro[5.5] undecane) displaced [(3)H]-MK-801 binding with K(i) values of 1.18, 2.59 and 3.64 microM, respectively. They were similarly potent against NMDA-induced currents in hippocampal neurons - IC(50) values of 1.51, 3.06 and 2.20 microM, respectively. In line with their moderate affinity, all were voltage-dependent (delta = 0.86, 0.96 and 0.89, respectively) and fast, open-channel blockers (k(on) 7.90, 1.70 and 2.60 x 10(4) M(-1) sec(-1), k(off) 0.13, 0.12 and 0.24 sec(-1), respectively). These compounds are also NMDA receptor antagonists in the CNS following systemic administration and have good therapeutic indices in a variety of in vivo behavioural models where glutamate is known to play a pivotal role. In view of their relatively low affinity and associated rapid kinetics, they should prove to be useful therapeutics in a wide range of CNS disorders.

Memantine: a NMDA receptor antagonist that improves memory by restoration of homeostasis in the glutamatergic system--too little activation is bad, too much is even worse

The neurotransmitter glutamate activates several classes of metabotropic receptor and three major types of ionotropic receptor--alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA), kainate and N-methyl-D-aspartate (NMDA). The involvement of glutamate mediated neurotoxicity in the pathogenesis of Alzheimer's disease (AD) is finding increasing scientific acceptance. Central to this hypothesis is the assumption that glutamate receptors, in particular of the NMDA type, are overactivated in a tonic rather than a phasic manner. Such continuous, mild, chronic activation ultimately leads to neuronal damage/death. Additionally, impairment of synaptic plasticity (learning) may result not only from neuronal damage per se but may also be a direct consequence of this continuous, non-contingent NMDA receptor activation. Complete NMDA receptor blockade has also been shown to impair neuronal plasticity, thus, both hypo- and hyperactivity of the glutamatergic system leads to dysfunction. Memantine received marketing authorization from the EMEA (European Medicines Agency) for the treatment of moderate to severe AD in Europe and was subsequently also approved by the FDA (Food and Drug Administration) for use in the same indication in the USA. Memantine is a moderate affinity, uncompetitive NMDA receptor antagonist with strong voltage-dependency and fast kinetics. This review summarizes existing hypotheses on the mechanism of action (MOA) of memantine in an attempt to understand how the accepted interaction with NMDA receptors could allow memantine to provide both neuroprotection and reverse deficits in learning/memory by the same MOA.

Combination of rimonabant and donepezil prolongs spatial memory duration

The observations that the cannabinoid(1)(CB(1)) receptor antagonist/inverse agonist, rimonabant, and the selective noncompetitive inhibitor of acetylcholinesterase (AChE), donepezil, improve performance in a variety of animal memory models, suggest that these neurochemical systems play integral roles in cognition. The present study tested whether each of these agents administered alone or in combination will prolong the duration of spatial memory. Rats were trained in a two-phase radial-arm maze procedure, consisting of acquisition and retrieval tests, which were separated by an 18 h delay. Each drug was administered 30 min before the acquisition phase, immediately after the acquisition phase, or 30 min before the retrieval test to assess acquisition/consolidation, consolidation, and retrieval mnemonic processes, respectively. Rimonabant or donepezil administered before the acquisition phase, but not immediately after acquisition or before retrieval, led to a significant decrease in the number of errors committed during the retrieval test. Combined administration of subthreshold doses of rimonabant and donepezil that had no discernable effects on performance when given alone, enhanced memory. These results taken together demonstrate that the delay radial-arm maze task is sufficiently sensitive to detect memory enhancing effects of these drugs. Moreover, these findings suggest that combined administration of subthreshold doses of rimonabant and donepezil can improve memory and may represent a novel approach to treat cognitive deficits associated with neurodegenerative disorders.

Alzheimer's disease: will advances made in the past turn the tide?

2006 marked the 40th year of publication for The Annals. Throughout its history, The Annals has provided important contributions to the development of clinical pharmacy. In 2007, we are continuing to publish articles reflecting on the history of clinical pharmacy through the eyes of practitioners, including those pioneering clinical pharmacy, as well as those who have more recently entered the profession and a well-established specialty. In addition, we are presenting articles and editorials from the early history of The Annals that have given direction and shape to the practice of clinical pharmacy (see page 1499).

Commentary on "Health economics and the value of therapy in Alzheimer's disease." Value therapy for Alzheimer's disease--a European perspective

The overall goal of value therapy is to provide the most efficient use of resources, taking into account both the cost and the value derived from a given technology or drug, and to assist in healthcare decision-making, because both cost and effectiveness are considered. After a short review of European Medicines Agency (EMEA) Committee for Medicinal Products for Human Use (CHMP) recommendations for the development of medications for Alzheimer's disease, we focus on the evidence with respect to cost and benefits obtained so far with acetylcholinesterase inhibitor (AChEI) and Memantine in the treatment of Alzheimer's disease. We then analyze the recommendations developed by professionals for the treatment of Alzheimer's disease at the national level in European countries, and finally we discuss how to utilize this process more homogenously in the future to assess value therapeutic values in Alzheimer's disease.

Reliability and validity of a short form of the Severe Impairment Battery in Korean Alzheimer's disease patients

The objective of this study was to evaluate the reliability and validity of a short form of the Severe Impairment Battery (SIB) for a Korean population. Eighty-four Alzheimer's disease patients with Clinical Dementia Rating (CDR) stages 2 (n = 32) or 3 (n = 52) and scores of less than 15 on the Korean version-Mini Mental State Examination (K-MMSE) participated in this study. Seventeen of the patients were men and 67 were women, and the mean age was 75 (SD = 10.4). Cronbach's coefficient alpha of the shortened SIB (SIB-S) was 0.93, and the item-total correlation was significant. Test-retest correlation for the total SIB-S score and subscale scores was significant, with the exception of the 'orienting to name' subscale. Construct validity was confirmed by evaluating the correlation between the SIB-S and the SIB, K-MMSE, CDR, and S-ADL; Spearman correlation coefficients were 0.96, 0.88, -0.67, and -0.63, respectively, which were found to be significant. The difference in the total SIB-S score and its subscale scores between the CDR 2 and CDR 3 groups was significant, except for the 'orienting to name' subscale. More severely demented patients also showed a wide range of the SIB-S score. Finally, the diagnostic accuracy of the SIB-S was high (AUC = 89.5%) in the differentiation of the CDR 2 and 3 patients. The sensitivity and specificity of the SIB-S were 91% and 80%, respectively, when the cut-off score was 32.5. Our results indicate that the SIB-S is a reliable and valid instrument for evaluating patients with severe dementia in the Korean population.

Nonmedical Influences on the Use of Cholinesterase Inhibitors in Dementia Care

We examined primary care physicians' (PCPs) attitudes toward cholinesterase inhibitors (ChEI) to better understand nonmedical factors influencing prescribing decisions in dementia care. In a cross-sectional, qualitative study, 40 PCPs were interviewed concerning their general approach to managing patients with dementia, and their care for a particular dementia case. Three readers independently identified and categorized themes associated with prescribing ChEI. Physicians' attitudes toward ChEI were also coded. Physicians were predominantly ambivalent (51%) or negative (31%) about prescribing ChEI for their patients with dementia. Nonmedical factors affecting prescribing included lack of knowledge, dependence on specialists, influence of family wishes and involvement, and physicians' values. PCPs reported that lack of knowledge and experience made prescribing decisions for ChEI challenging. Physicians reported feeling pressured by families to prescribe ChEI. Under these ambiguous conditions, some physicians prescribed medications simply to be able to offer "something" to patients.

Domain-specific improvement of cognition on memantine in patients with Alzheimer's disease treated with rivastigmine

OBJECTIVE

Cholinergic therapy is used in mild-to-moderate Alzheimer's disease (AD) and antiglutamatergic therapy in moderate-to-severe AD. Global scales, as commonly used in clinical trials, blur specifics of disease progression and drug effects. The objective was to assess combination therapy of rivastigmine plus memantine by specific neuropsychological tests in patients with mild-to-moderate AD.

METHODS

12-week-short multicenter open-label pilot study. Ninety patients with mild-to-moderate AD already on stable medication with rivastigmine (3-6 mg b.i.d.) additionally received memantine for 12 weeks. Subscales of the Alzheimer's Disease Assessment Scale (ADAS-cog), the Mini-Mental State Examination (MMSE) and additional neuropsychological tests (e.g. span tasks, semantic fluency) were assessed.

RESULTS

The scores in the ADAS-cog memory subscale, the MMSE score, and digit span and semantic fluency significantly improved on combination therapy.

CONCLUSION

Memory improvement was correlated with ADAS-cog memory score at baseline and inversely with age at onset of treatment. The data suggest that improvement on combination therapy results from an improvement of attention/executive function with secondary memory improvement, which will need to be confirmed in a subsequent double-blind study on a larger number of patients.