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The Cochrane Database of Systematic... Oct 2015People with Down syndrome are vulnerable to developing dementia at an earlier age than the general population. Alzheimer's disease and cognitive decline in people with... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
People with Down syndrome are vulnerable to developing dementia at an earlier age than the general population. Alzheimer's disease and cognitive decline in people with Down syndrome can place a significant burden on both the person with Down syndrome and their family and carers. Various pharmacological interventions, including donepezil, galantamine, memantine and rivastigmine, appear to have some effect in treating cognitive decline in people without Down syndrome, but their effectiveness for those with Down syndrome remains unclear.
OBJECTIVES
To assess the effectiveness of anti-dementia pharmacological interventions and nutritional supplements for treating cognitive decline in people with Down syndrome.
SEARCH METHODS
In January 2015, we searched CENTRAL, ALOIS (the Specialised Register of the Cochrane Dementia and Cognitive Improvement Group), Ovid MEDLINE, Embase, PsycINFO, seven other databases, and two trials registers. In addition, we checked the references of relevant reviews and studies and contacted study authors, other researchers and relevant drug manufacturers to identify additional studies.
SELECTION CRITERIA
Randomised controlled trials (RCTs) of anti-dementia pharmacological interventions or nutritional supplements for adults (aged 18 years and older) with Down syndrome, in which treatment was administered and compared with either placebo or no treatment.
DATA COLLECTION AND ANALYSIS
Two review authors independently assessed the risk of bias of included trials and extracted the relevant data. Review authors contacted study authors to obtain missing information where necessary.
MAIN RESULTS
Only nine studies (427 participants) met the inclusion criteria for this review. Four of these (192 participants) assessed the effectiveness of donepezil, two (139 participants) assessed memantine, one (21 participants) assessed simvastatin, one study (35 participants) assessed antioxidants, and one study (40 participants) assessed acetyl-L-carnitine.Five studies focused on adults aged 45 to 55 years, while the remaining four studies focused on adults aged 20 to 29 years. Seven studies were conducted in either the USA or UK, one between Norway and the UK, and one in Japan. Follow-up periods in studies ranged from four weeks to two years. The reviewers judged all included studies to be at low or unclear risk of bias.Analyses indicate that for participants who received donepezil, scores in measures of cognitive functioning (standardised mean difference (SMD) 0.52, 95% confidence interval (CI) -0.27 to 1.13) and measures of behaviour (SMD 0.42, 95% CI -0.06 to 0.89) were similar to those who received placebo. However, participants who received donepezil were significantly more likely to experience an adverse event (odds ratio (OR) 0.32, 95% CI 0.16 to 0.62). The quality of this body of evidence was low. None of the included donepezil studies reported data for carer stress, institutional/home care, or death.For participants who received memantine, scores in measures of cognitive functioning (SMD 0.05, 95% CI -0.43 to 0.52), behaviour (SMD -0.17, 95% CI -0.46 to 0.11), and occurrence of adverse events (OR 0.45, 95% CI 0.18 to 1.17) were similar to those who received placebo. The quality of this body of evidence was low. None of the included memantine studies reported data for carer stress, institutional/home care, or death.Due to insufficient data, it was possible to provide a narrative account only of the outcomes for simvastatin, antioxidants, and acetyl-L-carnitine. Results from one pilot study suggest that participants who received simvastatin may have shown a slight improvement in cognitive measures.
AUTHORS' CONCLUSIONS
Due to the low quality of the body of evidence in this review, it is difficult to draw conclusions about the effectiveness of any pharmacological intervention for cognitive decline in people with Down syndrome.
Topics: Acetylcarnitine; Adult; Antioxidants; Cognition; Cognition Disorders; Donepezil; Down Syndrome; Humans; Indans; Memantine; Middle Aged; Nootropic Agents; Piperidines; Randomized Controlled Trials as Topic; Simvastatin
PubMed: 26513128
DOI: 10.1002/14651858.CD011546.pub2 -
Journal of Neurochemistry Dec 2020Loss of oligodendrocytes, the myelin-forming cells of the central nervous system, and subsequent failure of myelin development result in serious neurological disorders...
Loss of oligodendrocytes, the myelin-forming cells of the central nervous system, and subsequent failure of myelin development result in serious neurological disorders such as multiple sclerosis. Using primary mouse embryonic neural stem cells (NSCs), we previously demonstrated that donepezil, an acetylcholinesterase inhibitor developed for the treatment of Alzheimer's disease, stimulates the differentiation of NSCs into oligodendrocytes and neurons, albeit at the expense of astrogenesis. However, the precise mechanisms underlying donepezil-induced differentiation remain unclear. In this study, we aimed at elucidating the molecular pathways contributing to donepezil-induced differentiation of mouse-induced pluripotent stem cell-derived neural stem cells (miPSC-NSCs). We used cell-based reporter gene arrays to investigate effects of donepezil on differentiation of miPSC-NSCs. Subsequently, we assessed the molecular pathway underlying donepezil action on differentiation of miPSC-NSCs into mature oligodendrocytes. Donepezil increased the transcriptional activity of estrogen response element under differentiating conditions. Moreover, estrogen receptors α (ERα) and β (ERβ) were highly expressed in MBP-positive mature oligodendrocytes. The ER antagonist ICI 182,780 abrogated the number of MBP-positive oligodendrocytes induced by donepezil, but showed no effect on the differentiation of miPSC-NSCs into Tuj1-positive neurons and GFAP-positive astrocytes. Furthermore, the donepezil-induced generation of mature oligodendrocytes from miPSC-NSC was significantly attenuated by antagonists and siRNA targeting ERα and ERβ. In conclusion, we demonstrated, for the first time, that donepezil-induced oligodendrogenesis is mediated through both ER subtypes, ERα and ERβ. Cover Image for this issue: https://doi.org/10.1111/jnc.14771.
Topics: Animals; Cell Differentiation; Cells, Cultured; Cholinesterase Inhibitors; Donepezil; Estrogen Receptor Antagonists; Fulvestrant; Induced Pluripotent Stem Cells; Mice; Oligodendroglia; RNA, Small Interfering; Receptors, Estrogen
PubMed: 31778582
DOI: 10.1111/jnc.14927 -
Biomolecules May 2020Microtubule affinity-regulating kinase (MARK4) plays a key role in Alzheimer's disease (AD) development as its overexpression is directly linked to increased tau...
Microtubule affinity-regulating kinase (MARK4) plays a key role in Alzheimer's disease (AD) development as its overexpression is directly linked to increased tau phosphorylation. MARK4 is a potential drug target of AD and is thus its structural features are employed in the development of new therapeutic molecules. Donepezil (DP) and rivastigmine tartrate (RT) are acetylcholinesterase (AChE) inhibitors and are used to treat symptomatic patients of mild to moderate AD. In keeping with the therapeutic implications of DP and RT in AD, we performed binding studies of these drugs with the MARK4. Both DP and RT bound to MARK4 with a binding constant () of 10 M. The temperature dependency of binding parameters revealed MARK-DP complex to be guided by static mode while MARK-RT complex to be guided by both static and dynamic quenching. Both drugs inhibited MARK4 with IC values of 5.3 μM (DP) and 6.74 μM (RT). The evaluation of associated enthalpy change (Δ) and entropy change (Δ) implied the complex formation to be driven by hydrogen bonding making it seemingly strong and specific. Isothermal titration calorimetry further advocated a spontaneous binding. In vitro observations were further complemented by the calculation of binding free energy by molecular docking and interactions with the functionally-important residues of the active site pocket of MARK4. This study signifies the implications of AChE inhibitors, RT, and DP in Alzheimer's therapy targeting MARK4.
Topics: Binding Sites; Cholinesterase Inhibitors; Donepezil; Humans; Molecular Docking Simulation; Nootropic Agents; Protein Binding; Protein Kinase Inhibitors; RNA Helicases; Rivastigmine
PubMed: 32443670
DOI: 10.3390/biom10050789 -
Journal of Alzheimer's Disease : JAD 2023Choline alphoscerate (alpha glyceryl phosphorylcholine, α-GPC) is a choline-containing phospholipid used as a medicine or nutraceutical to improve cognitive function... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Choline alphoscerate (alpha glyceryl phosphorylcholine, α-GPC) is a choline-containing phospholipid used as a medicine or nutraceutical to improve cognitive function impairment occurring in neurological conditions including adult-onset dementia disorders. Despite its 1985 marketing authorization, there are still discrepancies between countries regarding its approval as a prescription medicine and discussions about its effectiveness.
OBJECTIVE
This study aimed to evaluate the efficacy of the α-GPC compound for treating cognitive impairment in patients with adult-onset neurological disorders.
METHODS
Relevant studies were identified by searching PubMed, Web of Science, and Embase. Studies that evaluated the effects of α-GPC alone or in combination with other compounds on adult-onset cognitive impairment reporting cognition, function, and behavior were considered. We assessed the risk of bias of selected studies using the Cochrane risk of bias tool.
RESULTS
A total of 1,326 studies and 300 full-text articles were screened. We included seven randomized controlled trials (RCTs) and one prospective cohort study that met our eligibility criteria. We found significant effects of α-GPC in combination with donepezil on cognition [4 RCTs, mean difference (MD):1.72, 95% confidence interval (CI): 0.20 to 3.25], functional outcomes [3 RCTs, MD:0.79, 95% CI: 0.34 to 1.23], and behavioral outcomes [4 RCTs; MD: -7.61, 95% CI: -10.31 to -4.91]. We also observed that patients who received α-GPC had significantly better cognition than those who received either placebo or other medications [MD: 3.50, 95% CI: 0.36 to 6.63].
CONCLUSION
α-GPC alone or in combination with donepezil improved cognition, behavior, and functional outcomes among patients with neurological conditions associated with cerebrovascular injury.
Topics: Humans; Donepezil; Glycerylphosphorylcholine; Cognitive Dysfunction; Cognition Disorders; Cognition; Randomized Controlled Trials as Topic
PubMed: 36683513
DOI: 10.3233/JAD-221189 -
Acta Pharmaceutica (Zagreb, Croatia) Mar 2023The effects of 3,16-2-hydroxyethyl apovincaminate (HEAPO, RGH-10885) compared with those of two cholinesterase inhibitors, donepezil and galantamine, were examined in...
The effects of 3,16-2-hydroxyethyl apovincaminate (HEAPO, RGH-10885) compared with those of two cholinesterase inhibitors, donepezil and galantamine, were examined in naïve Wistar rats using standard active and passive avoidance tests. The active avoidance test (shuttle box) and two passive avoidance tests (step-through and step-down) were performed according to the experimental design. There were 10 groups of rats ( = 8) and the substances studied were applied orally before each testing session. In the active avoidance test, the number of conditioned stimuli (avoidances), unconditioned stimuli (escapes) and intertrial crossings were observed. In step-down and step-through passive avoidance tests, the latencies of reactions were observed. All the studied compounds showed positive effects in the learning and memory tests, compared to the controls. It was concluded that HEAPO, donepezil and galantamine had a memory-enhancing effect in active and passive avoidance tests.
Topics: Rats; Animals; Donepezil; Rats, Wistar; Galantamine; Avoidance Learning; Memory
PubMed: 36692469
DOI: 10.2478/acph-2023-0006 -
Annals of Indian Academy of Neurology 2020Alzheimer's disease (AD) is the most common cause of dementia worldwide in the older population. There is no disease-modifying therapy available for AD. The current...
OBJECTIVES
Alzheimer's disease (AD) is the most common cause of dementia worldwide in the older population. There is no disease-modifying therapy available for AD. The current standard of care drug therapy for AD is cholinesterase inhibitors, including donepezil. or brahmi is used in traditional Indian medicine for memory loss. We conducted a phase 2b randomized controlled trial (RCT) to find out the efficacy of brahmi and donepezil in AD and mild cognitive impairment (MCI).
PATIENTS AND METHODS
The study was planned as a 52 week, randomized, double-blind, parallel-group, phase-2 single-center clinical trial comparing the efficacy and safety of (brahmi) 300 mg OD and donepezil 10 mg OD for 12 months in 48 patients with AD and MCI-AD including cognitive and quality of life outcomes. The primary outcome was differences in the change from baseline of the neuropsychological tests [Alzheimer's disease assessment scale-cognitive subscale (ADAS-Cog) and postgraduate institute (PGI) memory scale] at 12 months between the intervention group (brahmi) and active comparison group (donepezil).
RESULTS
The study was terminated after 3 years and 9 months, after recruiting 34 patients, because of slow recruitment and a high dropout rate. Intention to treat analysis after adjusting for baseline confounders showed no difference in the rate of change in ADAS-Cog score from baseline at any time point, including the last follow-up. There was no difference in the rate of change in PGI Memory scale (PGIMS) at 3, 6, and 9 months. In the last follow-up, there was a significant difference in the change in total PGIMS score between brahmi and donepezil, while there was no difference in individual scores of the PGI memory scale.
CONCLUSION
This phase-2 RCT on the efficacy of brahmi vs. donepezil showed no significant difference between them after 1 year of treatment. Larger phase-3 trials, preferably multicentric, are required to find the superiority of brahmi over donepezil.
PubMed: 33688125
DOI: 10.4103/aian.AIAN_610_19 -
Biomolecules & Therapeutics May 2018A previous study in humans demonstrated the sustained inhibitory effects of donepezil on acetylcholinesterase (AChE) activity; however, the effective concentration of...
A previous study in humans demonstrated the sustained inhibitory effects of donepezil on acetylcholinesterase (AChE) activity; however, the effective concentration of donepezil in humans and animals is unclear. This study aimed to characterize the effective concentration of donepezil on AChE inhibition and impaired learning and memory in rodents. A pharmacokinetic study of donepezil showed a mean peak plasma concentration of donepezil after oral treatment (3 and 10 mg/kg) of approximately 1.2 ± 0.4 h and 1.4 ± 0.5 h, respectively; absolute bioavailability was calculated as 3.6%. Further, AChE activity was inhibited by increasing plasma concentrations of donepezil, and a maximum inhibition of 31.5 ± 5.7% was observed after donepezil treatment in hairless rats. Plasma AChE activity was negatively correlated with plasma donepezil concentration. The pharmacological effects of donepezil are dependent upon its concentration and AChE activity; therefore, we assessed the effects of donepezil on learning and memory using a Y-maze in mice. Donepezil treatment (3 mg/kg) significantly prevented the progression of scopolamine-induced memory impairment in mice. As the concentration of donepezil in the brain increased, the recovery of spontaneous alternations also improved; maximal improvement was observed at 46.5 ± 3.5 ng/g in the brain. In conclusion, our findings suggest that the AChE inhibitory activity and pharmacological effects of donepezil can be predicted by the concentration of donepezil. Further, 46.5 ± 3.5 ng/g donepezil is an efficacious target concentration in the brain for treating learning and memory impairment in rodents.
PubMed: 29463072
DOI: 10.4062/biomolther.2017.189 -
European Psychiatry : the Journal of... Feb 2024A short yet reliable cognitive measure is needed that separates treatment and placebo for treatment trials for Alzheimer's disease. Hence, we aimed to shorten the '...
BACKGROUND
A short yet reliable cognitive measure is needed that separates treatment and placebo for treatment trials for Alzheimer's disease. Hence, we aimed to shorten the ' (ADAS-Cog) and test its use as an efficacy measure.
METHODS
Secondary data analysis of participant-level data from five pivotal clinical trials of donepezil compared with placebo for Alzheimer's disease (N = 2,198). Across all five trials, cognition was appraised using the original 11-item ADAS-Cog. Statistical analysis consisted of sample characterization, item response theory (IRT) to identify an ADAS-Cog short version, and mixed models for repeated-measures analysis to examine the effect sizes of ADAS-Cog change on the original and short versions in the placebo versus donepezil groups.
RESULTS
Based on IRT, a short ADAS-Cog was developed with seven items and two response options. The original and short ADAS-Cog correlated at baseline and at weeks 12 and 24 at 0.7. Effect sizes based on mixed modeling showed that the short and original ADAS-Cog separated placebo and donepezil comparably (ADAS-Cog original ES = 0.33, 95% CI = 0.29, 0.40, ADAS-Cog short ES = 0.25, 95% CI =0.23, 0.34).
CONCLUSIONS
IRT identified a short ADAS-cog version that separated donepezil and placebo, suggesting its clinical potential for assessment and treatment monitoring.
Topics: Humans; Alzheimer Disease; Donepezil; Cognition Disorders; Cognition
PubMed: 38389390
DOI: 10.1192/j.eurpsy.2024.14 -
Cardiology Research and Practice 2018Donepezil, a widely used cholinesterase inhibitor for treating Alzheimer's disease, has been reported to induce bradyarrhythmias and torsade de pointes. In this study,...
OBJECTIVE
Donepezil, a widely used cholinesterase inhibitor for treating Alzheimer's disease, has been reported to induce bradyarrhythmias and torsade de pointes. In this study, we aimed at determining electrocardiogram changes of donepezil administration in elderly patients with ischemic heart disease, who tend to suffer from cognitive disorders.
METHODS
Sixty patients with ischemic heart disease and mild cognitive impairment were treated with donepezil (5 mg/day) and followed up for at least four weeks. A twenty-four-hour ambulatory electrocardiogram was performed for the analysis of heart rate variability. The ECG parameters including heart rate (HR), PR and RR intervals, QT interval, and QRS duration were recorded at the baseline and after donepezil administration.
RESULTS
Donepezil administration resulted in significant reduction in mean HR and the lowest HR and prolongation of PR and RR intervals, whereas it had no significant effects on QRS duration and QT parameters including QT, corrected QT interval, QT dispersion, and T interval. HRV analysis showed that donepezil administration significantly improved parasympathetic function, indicated by decreased low/high frequency (LF/HF) ratio and high frequency (HF) components and oscillation of RR intervals.
CONCLUSIONS
These data demonstrated that donepezil administration decreased HR, prolonged PR interval, and increased parasympathetic function without affecting QRS duration and QT intervals, suggesting that it can be used safely in elderly patients with ischemic heart disease.
PubMed: 29850230
DOI: 10.1155/2018/9141320 -
Evidence-based Complementary and... 2018Donepezil is the most common drug used in the treatment of disorders associated with memory loss, especially that in Alzheimer's disease. Healthy individuals however...
BACKGROUND
Donepezil is the most common drug used in the treatment of disorders associated with memory loss, especially that in Alzheimer's disease. Healthy individuals however have continued to use it as a memory enhancer. This study was aimed at evaluating the combined therapy of donepezil and propolis on cognition in . flies were divided into five groups and fed with the different treatment doses of ethanolic extract of propolis and donepezil as follows: normal food, propolis 250 mg/mL, propolis 50 mg/mL, donepezil 0.001M, and donepezil 0.001M/propolis 50 mg/mL added to their food. The flies were fed from larval stage for 30 days. The memory and learning tests were conducted after every 10 days to assess improvement with time.
RESULTS
The results obtained showed that the combination of propolis with donepezil caused a remarkable improvement in both the short- and long-term memory. In addition, there was a dose dependent improvement with the administration of propolis.
CONCLUSION
Propolis extract obtained from different parts of Uganda expressed cognitive improvement when coadministered with donepezil in wild type .
PubMed: 30158994
DOI: 10.1155/2018/3717328