Cholinesterase Inhibitor and Memantine Use in Newly Admitted Nursing Home Residents with Dementia

OBJECTIVES: To quantify the use of cholinesterase inhibitors (ChEIs) and memantine in nursing home (NH) residents with dementia upon NH admission and 3 months later and to examine factors associated with reduction in therapy.

DESIGN: Retrospective cohort study.

SETTING: Nationwide sample of U.S. NHs.

PARTICIPANTS: Three thousand ?ve hundred six NH residents with dementia newly admitted in 2006.

MEASUREMENTS: Data from pharmacy dispensing records were used to determine ChEI and memantine medication use upon NH admission and at 3-month follow-up. The Minimum Data Set was used to determine resident- and facility-level characteristics. Severity of dementia was de?ned using the Cognitive Performance Scale (CPS).

RESULTS: Overall, 40.1% (n51,407) of newly admitted NH residents with dementia received ChEIs and memantine on NH admission. Use of ChEIs and memantine on admission was significantly greater in residents with mild to moderately severe dementia (41.2%) than in those with advanced dementia (33.3%, P5.001). After 3 months, ChEI and memantine use decreased by about half in both groups (48.6% with mild to moderately severe dementia vs 57.0% with advanced dementia, Po.05). NH residents with advanced dementia were significantly more likely reduce their use of ChEIs and memantine than those with mild to moderately severe dementia (odds ratio 51.44, 95% con?dence interval 51.03–2.01, P5.04).

CONCLUSION: Many NH residents with advanced dementia receive ChEIs and memantine upon NH admission, and approximately half of these decrease their medication use over the ensuing months. Further study is required to optimize use of ChEIs and memantine in NH populations and to determine the effects of withdrawing therapy on resident outcomes.

Donepezil and memantine for moderate-to-severe Alzheimer's disease

Background: Clinical trials have shown the benefits of cholinesterase inhibitors for the treatment of mild-to-moderate Alzheimer's disease. It is not known whether treatment benefits continue after the progression to moderate-to-severe disease. Methods: We assigned 295 community-dwelling patients who had been treated with donepezil for at least 3 months and who had moderate or severe Alzheimer's disease (a score of 5 to 13 on the Standardized Mini-Mental State Examination [SMMSE, on which scores range from 0 to 30, with higher scores indicating better cognitive function]) to continue donepezil, discontinue donepezil, discontinue donepezil and start memantine, or continue donepezil and start memantine. Patients received the study treatment for 52 weeks. The coprimary outcomes were scores on the SMMSE and on the Bristol Activities of Daily Living Scale (BADLS, on which scores range from 0 to 60, with higher scores indicating greater impairment). The minimum clinically important differences were 1.4 points on the SMMSE and 3.5 points on the BADLS.
Results: Patients assigned to continue donepezil, as compared with those assigned to discontinue donepezil, had a score on the SMMSE that was higher by an average of 1.9 points (95% confidence interval [CI], 1.3 to 2.5) and a score on the BADLS that was lower (indicating less impairment) by 3.0 points (95% CI, 1.8 to 4.3) (P<0.001 for both comparisons). Patients assigned to receive memantine, as compared with those assigned to receive memantine placebo, had a score on the SMMSE that was an average of 1.2 points higher (95% CI, 0.6 to 1.8; P<0.001) and a score on the BADLS that was 1.5 points lower (95% CI, 0.3 to 2.8; P = 0.02). The efficacy of donepezil and of memantine did not differ significantly in the presence or absence of the other. There were no significant benefits of the combination of donepezil and memantine over donepezil alone.
Conclusions: In patients with moderate or severe Alzheimer's disease, continued treatment with donepezil was associated with cognitive benefits that exceeded the minimum clinically important difference and with significant functional benefits over the course of 12 months. (Funded by the U.K. Medical Research Council and the U.K. Alzheimer's Society; Current Controlled Trials number, ISRCTN49545035).

DOMINO-AD protocol:donepezil and memantine in moderate to severe Alzheimer's disease - a multicentre RCT

Alzheimer's disease (AD) is the commonest cause of dementia. Cholinesterase inhibitors, such as donepezil, are the drug class with the best evidence of efficacy, licensed for mild to moderate AD, while the glutamate antagonist memantine has been widely prescribed, often in the later stages of AD. Memantine is licensed for moderate to severe dementia in AD but is not recommended by the England and Wales National Institute for Health and Clinical Excellence. However, there is little evidence to guide clinicians as to what to prescribe as AD advances; in particular, what to do as the condition progresses from moderate to severe. Options include continuing cholinesterase inhibitors irrespective of decline, adding memantine to cholinesterase inhibitors, or prescribing memantine instead of cholinesterase inhibitors. The aim of this trial is to establish the most effective drug option for people with AD who are progressing from moderate to severe dementia despite treatment with donepezil.

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.

Efficacy of memantine for agitation in Alzheimer's dementia:a randomised double-blind placebo controlled trial

Background - Agitation in Alzheimer’s disease (AD) is common and associated with poor patient life-quality and carer distress. The best evidence-based pharmacological treatments are antipsychotics which have limited benefits with increased morbidity and mortality. There are no memantine trials in clinically significant agitation but post-hoc analyses in other populations found reduced agitation. We tested the primary hypothesis, memantine is superior to placebo for clinically significant agitation, in patients with moderate-to-severe AD. Methods and Findings - We recruited 153 participants with AD and clinically significant agitation from care-homes or hospitals for a double-blind randomised-controlled trial and 149 people started the trial of memantine versus placebo. The primary outcome was 6 weeks mixed model autoregressive analysis of Cohen-Mansfield Agitation Inventory (CMAI). Secondary outcomes were: 12 weeks CMAI; 6 and 12 weeks Neuropsychiatric symptoms (NPI), Clinical Global Impression Change (CGI-C), Standardised Mini Mental State Examination, Severe Impairment Battery. Using a mixed effects model we found no significant differences in the primary outcome, 6 weeks CMAI, between memantine and placebo (memantine lower -3.0; -8.3 to 2.2, p = 0.26); or 12 weeks CMAI; or CGI-C or adverse events at 6 or 12 weeks. NPI mean difference favoured memantine at weeks 6 (-6.9; -12.2 to -1.6; p = 0.012) and 12 (-9.6; -15.0 to -4.3 p = 0.0005). Memantine was significantly better than placebo for cognition. The main study limitation is that it still remains to be determined whether memantine has a role in milder agitation in AD. Conclusions - Memantine did not improve significant agitation in people with in moderate-to-severe AD. Future studies are urgently needed to test other pharmacological candidates in this group and memantine for neuropsychiatric symptoms.

Memantine combined with an acetyl cholinesterase inhibitor:hope for the future?

Background:Memantine and cholinesterase inhibitors (ChEI) have distinct pharmacological actions, and interest in the use of combination therapy for Alzheimer's disease (AD) is increasing. Objective: To assess the available data on the use of memantine–ChEI combination and to develop evidence-based recommendations.Method: A systematic literature review with detailed discussion of the current evidence base. Results: Available data are limited: five studies of which two were randomized, double-blind, placebo-controlled trials. One study indicated that memantine–ChEI combination is not significantly more effective than placebo–ChEI in mild to moderate AD, but data were published in abstract and poster form only. A second study indicated that the memantine–ChEI combination is significantly more effective than placebo–ChEI in moderate to severe AD. The calculated effect sizes of 0.36 on cognition and 0.12 on function, which were the primary outcomes, were small, indicating a clinically minimal effect on cognition and no effect on function. No data are available on whether combination treatment is more effective than memantine monotherapy. Conclusion: The available data do not justify the use of combination therapy. Future studies should include three arms (memantine–placebo, placebo–ChEI, and memantine–ChEI), be of an adequate size and duration, and use pragmatic measures. Clinicians should have full access to data from any future trials.

The biology of the glutamatergic system and potential role in migraine

Migraine is a common genetically linked neurovascular disorder. Approximately ~12% of the Caucasian population are affected including 18% of adult women and 6% of adult men (1, 2). A notable female bias is observed in migraine prevalence studies with females affected ~3 times more than males and is credited to differences in hormone levels arising from reproductive achievements. Migraine is extremely debilitating with wide-ranging socioeconomic impact significantly affecting people's health and quality of life. A number of neurotransmitter systems have been implicated in migraine, the most studied include the serotonergic and dopaminergic systems. Extensive genetic research has been carried out to identify genetic variants that may alter the activity of a number of genes involved in synthesis and transport of neurotransmitters of these systems. The biology of the Glutamatergic system in migraine is the least studied however there is mounting evidence that its constituents could contribute to migraine. The discovery of antagonists that selectively block glutamate receptors has enabled studies on the physiologic role of glutamate, on one hand, and opened new perspectives pertaining to the potential therapeutic applications of glutamate receptor antagonists in diverse neurologic diseases. In this brief review, we discuss the biology of the Glutamatergic system in migraine outlining recent findings that support a role for altered Glutamatergic neurotransmission from biochemical and genetic studies in the manifestation of migraine and the implications of this on migraine treatment.

Neurochemical regulation of auditory information processing studied with EEG/MEG: application to schizophrenia

Cognitive impairments of attention, memory and executive functions are a fundamental feature of the pathophysiology of schizophrenia. The neurophysiological and neurochemical changes in the auditory cortex are shown to underlie cognitive impairmentsin schizophrenia patients. Functional state of the neural substrate of auditory information processing could be objectively and non-invasively probed with auditory event-related potentials (ERPs) and event- related fields (ERFs). In the current work, we explored the neurochemical effect on the neural origins of auditory information processing in relation to schizophrenia. By means of ERPs/ERFs we aimed to determine how neural substrates of auditory information processing are modulated by antipsychotic medication in schizophrenia spectrum patients (Studies I, II) and by neuropharmacological challenges in healthy human subjects (Studies III, IV). First, with auditory ERPs we investigated the effects of olanzapine (Study I) and risperidone (Study II) in a group of patients with schizophrenia spectrum disorders. After 2 and 4 weeks of treatment, olanzapine has no significant effects on mismatch negativity(MMN) and P300, which, as it has been suggested, respectively reflect preattentive and attention-dependent information processing. After 2 weeks of treatment, risperidone has no significant effect on P300, however risperidone reduces P200 amplitude. This latter effect of risperidone on neural resources responsible for P200 generation could be partly explained through the action of dopamine. Subsequently, we used simultaneous EEG/MEG to investigate the effects of memantine (Study III) and methylphenidate (Study IV) in healthy subjects. We found that memantine modulates MMN response without changing other ERP components. This could be interpreted as being due to the possible influence of memantine through the NMDA receptors on auditory change- detection mechanism, with processing of auditory stimuli remaining otherwise unchanged. Further, we found that methylphenidate does not modulate the MMN response. This finding could indicate no association between catecholaminergic activities and electrophysiological measures of preattentive auditory discrimination processes reflected in the MMN. However, methylphenidate decreases the P200 amplitudes. This could be interpreted as a modulation of auditory information processing reflected in P200 by dopaminergic and noradrenergic systems. Taken together, our set of studies indicates a complex pattern of neurochemical influences produced by the antipsychotic drugs in the neural substrate of auditory information processing in patients with schizophrenia spectrum disorders and by the pharmacological challenges in healthy subjects studied with ERPs and ERFs.

Kirjallisuusosa: Alzheimerin taudin rottamallien vastaavuus tautiin ihmisessä ja mallien käyttökelpoisuus

Kirjallisuusosa: Alzheimerin taudin hoitoon olisi tarvetta uusille taudinkulkuun vaikuttaville lääkeaineille. Niiden kehittämiseksi tarvitaan eläinmalleja, joissa esiintyy taudin patofysiologisia piirteitä. Rottamalleista vanhemmat skopolamiini- tai MK-801-häirintä sekä ikääntyneiden rottien käyttö eivät kovin hyvin vastaa taudin patofysiologiaa, vaikka niissä eläimen muisti käyttäytymiskokeissa onkin heikentynyt. Uudemmat transgeeniset rottamallit ja mallit, joissa annetaan Aβ:a aivoihin, ilmentävät huomattavasti paremmin Alzheimerin taudin kaltaista tilaa aivoissa ainakin Aβ:n osalta. Taupatofysiologiaa ei silti kummassakaan näistä malleista juuri esiinny. Toisaalta Aβ:lla näyttäisi olevan huomattavasti tau:ta suurempi rooli taudissa, joten sen ilmeneminen mallissa onkin keskeisempi tekijä. Nämä mallit ilmentävät melko suurelti osin yhtä hyvin Alzheimerin taudin patofysiologiaa. Aβ:n antaminen on hieman yksinkertaisempi suorittaa käytännössä, sillä siinä ei tarvitse luoda transgeenista kantaa. Toisaalta transgeenisessa mallissa Aβ-patofysiologia syntyy enemmän Alzheimerin taudin kaltaisesti solujen sisällä eikä valmiita aggregoituvia Aβ-peptidejä anneta ulkopuolelta aivoihin. Molemmat mallit ovat kuitenkin käyttökelpoisia, ja soveltuvat erityisesti Aβ:an vaikuttavien lääkeaineiden kehittämiseen. Kokeellinen osa: Kokeen tarkoituksena oli validoida kohotettu ristikko-sokkelo (elevated plus-maze, EPM) hiirillä kognitiomallina. Kokeessa käytettiin kahden koekerran (trial, T) menetelmää, jossa koekertojen pituus oli viisi minuuttia. Näin saatiin useita oppimista kuvaavia parametreja. Hiirille yritettiin saada muistihäiriö aikaviiveen avulla (koekertojen väli 1-18 vrk) tai antamalla muskariinireseptoriantagonistia skopolamiinia (0,1-0,8 mg/kg i.p.) 30 minuuttia ennen T1:tä. Nämä kokeet suoritettiin sekä C57BL/6J- että ICR:(CD-1)-hiirillä. Aikaviivekokeissa ainut ryhmä, jolla oli viitettä unohtamisesta, oli ICR:(CD-1)-hiirien 18 vrk:n ryhmä. Tämän perusteella tutkittiin vielä 21 vuorokauden aikaväli, mutta selvää muistihäiriötä ei esiintynyt. Skopolamiini ei häirinnyt muistia ICR:(CD-1)-hiirillä, mutta C57BL/6J-hiirillä 0,2 mg/kg:n annoksesta ylöspäin merkitsevä muistihäiriö esiintyi. Näin ollen jatkokokeissa käytettäväksi valittiin skopolamiinin annos 0,2 mg/kg C57BL/6J-hiirillä, ja siinä tutkittiin donepetsiilin (0,3, 0,8 ja 1,5 mg/kg s.c), memantiinin (5,0 ja 10,0 mg/kg s.c) ja kokeellisen 5-HT6-antagonistin SB742457:n (1,5 ja 6,0 mg/kg s.c) muistia parantavia vaikutuksia. Tutkittavat lääkeaineet annettiin 40 minuuttia ennen T1:tä ja skopolamiini 30 minuuttia ennen. Memantiinilla (5,0 mg/kg) oli selkeä skopolamiinin heikentämää kognitiota parantava vaikutus ja donepetsiilillakin (1,5 mg/kg) suuntaus tähän. Tulosten perusteella malli näyttäisi soveltuvan muisti- ja oppimisvaikutusten tutkimiseen käytettäväksi malliksi.