Evidence-based pharmacotherapy of Alzheimer's disease

Access from healthcare professionals to evidence-based pharmacotherapy in allergy management

PURPOSE OF REVIEW

Access to evidence-based pharmacotherapy (EBP) is crucial in effectively managing allergies. Allergy conditions, including rhinitis, asthma, and dermatitis, require treatment guided by scientific evidence. However, healthcare professionals face challenges in accessing relevant information.

RECENT FINDINGS

The dynamic nature of allergy research, coupled with limited resources and variability in practice guidelines, complicates decision-making.

SUMMARY

To enhance access, healthcare institutions should invest in comprehensive online resources tailored to allergy management, such as databases and platforms. Advances in algorithm development have shown that artificial intelligence and machine learning can enhance clinical decision-making. Integrating allergy-specific Clinical Decision Support Systems (CDSS) into electronic health records can assist professionals in making EBP decisions at the point of care. Continuing education and training programs focused on allergy management can keep healthcare providers updated on the latest research and guidelines. Multidisciplinary teams facilitate knowledge exchange and standardize practice approaches. Social media outlets can be a great route to publicize work carried out or in progress to a target audience of interest. By bridging the gap between evidence and practice in allergy management, healthcare systems can ensure optimal care for patients, alleviating the burden of allergic diseases on individuals and society.

A Potential Role for the Ketogenic Diet in Alzheimer's Disease Treatment: Exploring Pre-Clinical and Clinical Evidence

Given the remarkable progress in global health and overall quality of life, the significant rise in life expectancy has become intertwined with the surging occurrence of neurodegenerative disorders (NDs). This emerging trend is poised to pose a substantial challenge to the fields of medicine and public health in the years ahead. In this context, Alzheimer's disease (AD) is regarded as an ND that causes recent memory loss, motor impairment and cognitive deficits. AD is the most common cause of dementia in the elderly and its development is linked to multifactorial interactions between the environment, genetics, aging and lifestyle. The pathological hallmarks in AD are the accumulation of β-amyloid peptide (Aβ), the hyperphosphorylation of tau protein, neurotoxic events and impaired glucose metabolism. Due to pharmacological limitations and in view of the prevailing glycemic hypometabolism, the ketogenic diet (KD) emerges as a promising non-pharmacological possibility for managing AD, an approach that has already demonstrated efficacy in addressing other disorders, notably epilepsy. The KD consists of a food regimen in which carbohydrate intake is discouraged at the expense of increased lipid consumption, inducing metabolic ketosis whereby the main source of energy becomes ketone bodies instead of glucose. Thus, under these dietary conditions, neuronal death via lack of energy would be decreased, inasmuch as the metabolism of lipids is not impaired in AD. In this way, the clinical picture of patients with AD would potentially improve via the slowing down of symptoms and delaying of the progression of the disease. Hence, this review aims to explore the rationale behind utilizing the KD in AD treatment while emphasizing the metabolic interplay between the KD and the improvement of AD indicators, drawing insights from both preclinical and clinical investigations. Via a comprehensive examination of the studies detailed in this review, it is evident that the KD emerges as a promising alternative for managing AD. Moreover, its efficacy is notably enhanced when dietary composition is modified, thereby opening up innovative avenues for decreasing the progression of AD.

Investigating Owner Use of Dietary Supplements in Dogs with Canine Cognitive Dysfunction

Canine cognitive dysfunction (CCD) is becoming increasingly recognized in veterinary medicine, as dogs live longer and with CCD being highly prevalent among the elderly dog population. Various studies have shown that diet and dietary supplementation can positively influence the clinical signs of CCD, especially if given at an early stage. The aim of this study was to investigate owner use of dietary supplements (DSs) in dogs with age-related behavioral changes. An observational study based on an online questionnaire for owners of dogs with age-related behavioral changes was performed. Out of a total of 394 owners who completed the survey, after noticing age-related behavioral changes, over half of the dogs received DSs (54%), whereas only 8% reported changing their dog's base diet. The most used DS was fish oil (48%). The use of DSs should be discussed with and monitored by veterinary surgeons since many geriatric patients have multi-morbidities, may have specific nutritional requirements and receive multi-faceted medications.

Synthesis, anticholinesterase activity, molecular docking, and molecular dynamic simulation studies of 1,3,4-oxadiazole derivatives

Two new series of 1,3,4-oxadiazoles bearing pyridine and thiazole heterocycles (4a-h and 5a-h) were synthesized (2,5-disubstituted-1,3,4-oxadiazoles). The structures of these newly synthesized compounds were confirmed by ¹ H nuclear magnetic resonance (NMR), ¹³ C NMR, high-resolution mass spectrometric and Fourier transform infrared spectroscopic methods. All these compounds were evaluated for their enzyme inhibitory activities against two cholinesterase enzymes, acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). From the studies, we identified compounds 4a, 4h, 5a, 5d, and 5e as selective AChE inhibitors, with IC₅₀ values ranging from 0.023 to 0.037 μM. Furthermore, docking studies of these compounds were performed at the active sites of their target enzymes. The molecular docking study showed that 5e possessed an ideal docking pose with interactions inside AChE.

Preparation and Release Profiles in Vitro/Vivo of Galantamine Pamoate Loaded Poly (Lactideco-Glycolide) (PLGA) Microspheres

Patient’s poor compliance and the high risk of toxic effects limit the clinical use of galantamine hydrobromide. To overcome these drawbacks, the sustained-release galantamine pamoate microspheres (GLT-PM-MS) were successfully developed using an oil/water emulsion solvent evaporation method in this study. Physicochemical properties of GLT-PM-MS were carefully characterized, and the in vitro and in vivo drug release behaviors were well studied. Results showed that the morphology of optimized microspheres were spherical with smooth surfaces and core-shell interior structure. Mean particle size, drug loading and entrapment efficiency were 75.23 ± 1.79 μm, 28.01 ± 0.81% and 87.12 ± 2.71%, respectively. The developed GLT-PM-MS were found to have a sustained release for about 24 days in vitro and the plasma drug concentration remained stable for 17 days in rats. These results indicated that GLT-PM-MS could achieve the sustained drug release purpose and be used in clinical trial.

Effect of QT Prolongation in Patients Taking Cholinesterase Inhibitors (Donepezil) for Alzheimer's Disease

Background: Cholinesterase inhibitors such as donepezil are used in the treatment of Alzheimer’s disease. Patients taking cholinesterase inhibitors can develop cholinergically mediated QT prolongation, which may lead to life-threatening arrhythmias. In this study we investigated the corrected QT interval (QTc) of patients taking donepezil.

Methods and Results: This study enrolled 114 outpatients attending Tarumizu Chuo Hospital. Subjects were divided into a donepezil group (n=57) or an age- and sex-matched control group (n=57). Physical findings, laboratory data, and electrocardiographic parameters were compared between the groups. QTc was significantly prolonged (mean [±SD] 0.443±0.032 s vs. 0.426±0.026s; P<0.001) and the percentage of patients with prolonged QTc was significantly higher (30% vs. 9%; P<0.01) in the donepezil than control group. Furthermore, in the donepezil group, QTc was significantly prolonged after patients started taking donepezil compared with baseline (from 0.433±0.034 to 0.442±0.033s; n=46; P<0.05). On univariate analysis, QTc was significantly associated with taking donepezil, as well as with hemoglobin, serum calcium concentration, and estimated glomerular filtration rate (eGFR; all P<0.01). On multivariate analysis, QTc was significantly associated with taking donepezil (P<0.001), serum potassium concentration (P<0.05), and eGFR (P<0.05).

Conclusions: The incidence of QTc prolongation was more frequent in patients taking donepezil than in the control group, and was difficult to predict. Periodic electrocardiogram examinations are recommended considering the possibility of adverse events, such as fatal arrhythmias.

Canine Cognitive Dysfunction: Pathophysiology, Diagnosis, and Treatment

Canine cognitive dysfunction (CCD) is the canine analog of human Alzheimer disease (AD). The pathophysiology of CCD/AD is multifaceted. CCD is common in aged (>8 years) dogs, affecting between 14% and 35% of the pet dog population. Apparent confusion, anxiety, disturbance of the sleep/wake cycle, and decreased interaction with owners are all common clinical signs of CCD. Although there is no cure for CCD, several proven effective therapeutic approaches are available for improving cognitive ability and maintaining a good quality of life; instituting such therapies early in the disease course is likely to have the greatest positive clinical effect.

Role of green tea catechins in prevention of age-related cognitive decline: Pharmacological targets and clinical perspective

Over the past decade, a wide range of scientific investigations have been performed to reveal neuropathological aspects of cognitive disorders; however, only limited therapeutic approaches currently exist. The failures of conventional therapeutic options as well as the predicted dramatic rise in the prevalence of cognitive decline in the coming future show the necessity for novel therapeutic agents. Recently, a wide range of research has focused on pharmacological activities of green tea catechins worldwide. Current investigations have clarified mechanistic effects of the catechins in inflammatory cascades, oxidative damages, different cellular transcription as well as transduction pathway in various body systems. It has been demonstrated that green tea polyphenols prevent age-related neurodegeneration through improvement of endogenous antioxidant defense mechanisms, modulation of neural growth factors, attenuation of neuroinflammatory pathway, and regulation of apoptosis. The catechins exhibited beneficial effects in cellular and animal models of neurodegenerative diseases including Alzheimer's disease, MS, and Parkinson's disease. The present review discusses the current pharmacological targets, which can be involved in the treatment of cognitive decline and addresses the action of catechin derivatives elicited from green tea on the multiple neural targets.

Cardiovascular monitoring with acetylcholinesterase inhibitors: a clinical protocol

There has been significant anxiety among prescribers regarding the potential for cardiac adverse effects associated with acetylcholinesterase (AChE) inhibitors in Alzheimer's disease. There is no consensus on how to manage this cardiovascular risk, and memory clinics vary widely in their practice. Review of published evidence reveals that the incidence of cardiovascular side-effects is low, and that serious adverse events are rare. Intensive cardiovascular screening such as pre-treatment electrocardiograms or 24 h cardiac monitoring is not justified. Furthermore, there are no high-risk groups to target. This article suggests pragmatic guidelines for managing cardiovascular risk in patients receiving AChE inhibitors. The guidelines are intended to be easy to incorporate into routine clinical practice in a memory clinic.

A study of donepezil in female breast cancer survivors with self-reported cognitive dysfunction 1 to 5 years following adjuvant chemotherapy

PURPOSE

Some breast cancer survivors report cognitive difficulties greater than 1 year after chemotherapy. Acetylcholinesterase inhibitors (AChEI) may improve cognitive impairment. We conducted a randomized, placebo-controlled, pilot study to assess the feasibility of using the AChEI, donepezil, to improve subjective and objective measures of cognitive function in breast cancer survivors.

METHODS

Women who received adjuvant chemotherapy 1-5 years prior with current cognitive dysfunction symptoms were randomized to 5 mg of donepezil/day vs placebo for 6 weeks and if tolerated 10 mg/day for 18 weeks for a total of 24 weeks. A battery of validated measures of attention, memory, language, visuomotor skills, processing speed, executive function, and motor dexterity and speed was administered at baseline and at 24 and 36 weeks. Subjective cognitive function, fatigue, sleep, mood, and health-related quality of life were evaluated at baseline and at 12, 24, and 36 weeks.

RESULTS

Sixty-two patients were enrolled, 76 % completed the study, self-reported compliance was 98 %, and toxicities were minimal. At the end of treatment, the donepezil group performed significantly better than the control group on two parameters of memory-the Hopkins Verbal Learning Test -Revised (HVLT-R) Total Recall (p = 0.033) and HVLT-R Discrimination (p = 0.036). There were no significant differences on other cognitive variables or in subjective cognitive function or quality of life.

CONCLUSION

Accrual to this feasibility trial was robust, retention was good, compliance was excellent, and toxicities were minimal.

IMPLICATIONS FOR CANCER SURVIVORS

Randomized clinical trials in breast cancer survivors to improve cognitive dysfunction are feasible. A phase III trial testing the efficacy of donepezil is warranted given these pilot results.

Effects of Rivastigmine on Memory and Cognition in Multiple Sclerosis

Background:

Cognitive dysfunction is one of the common clinical symptoms in multiple sclerosis (MS), but there is no effective treatment for it.

Objective:

The aim of this study was to evaluate the effect of rivastigmine in treating memory and cognitive dysfunction in MS.

Methods:

A single-center double-blind placebo-controlled randomized clinical trial conducted from October 2005 to February 2007. Sixty definite MS patients with cognitive impairment age 16 to 54 years were randomly allocated to receive a 12-week treatment course of either rivastigmine (1.5 mg once a day increment over 4 weeks to 3 mg twice daily) or placebo. Response to treatment was assessed by the Wechsler Memory Scale (WMS) at baseline and 12 weeks after start of therapy.

Results:

A slight, but significant memory improvement occurred in both groups. Of the 30 patients treated with rivastigmine, the mean (SD) WMS general memory score increased from 60.3 (4.2) at baseline to 64.9 (5.3) at the end of study period (P<0.001). Correspondingly, in the 30 patients treated with placebo, the mean (SD) WMS general memory score increased from 60.5 (4.9) to 64.5 (3.7) (P < 0.001). The average WMS general memory score at the end of trial did not changed between rivastigmine and placebo group (mean difference, 0.4; 95% CI, -2.0, 2.8).

Conclusion:

No significant differences were seen between rivastigmine and placebo on the mean (SD) WMS general memory score. A larger multicenter study of rivastigmine in MS is warranted in order to more definitely assess the efficacy of this intervention.

Learning in Alzheimer's disease is facilitated by social interaction

Seminal work in Gary Van Hoesen's laboratory at Iowa in the early 1980s established that the hallmark neuropathology of Alzheimer's disease (AD; neurofibrillary tangles) had its first foothold in specific parts of the hippocampal formation and entorhinal cortex, effectively isolating the hippocampus from much of its input and output and causing the distinctive impairment of new learning that is the leading early characteristic of the disease (Hyman et al., 1984). The boundaries and conditions of the anterograde memory defect in patients with AD have been a topic of intense research interest ever since (e.g., Graham and Hodges, 1977; Nestor et al., 2006). For example, it has been shown that patients with AD may acquire some new semantic information through methods such as errorless learning, but learning under these conditions is typically slow and inefficient. Drawing on a learning paradigm (a collaborative referencing task) that was previously shown to induce robust and enduring learning in patients with hippocampal amnesia, we investigated whether this task would be effective in promoting new learning in patients with AD. We studied five women with early-stage AD and 10 demographically matched healthy comparison participants, each interacting with a familiar communication partner. AD pairs displayed significant and enduring learning across trials, with increased accuracy and decreased time to complete trials, in a manner indistinguishable from healthy comparison pairs, resulting in efficient and economical communication. The observed learning here most likely draws on neural resources outside the medial temporal lobes. These interactive communication sessions provide a potent learning environment with significant implications for memory intervention.

A drug utilization study of cognition enhancers in dementia in a tertiary care hospital in mumbai

BACKGROUND

Cognitive decline is one of the important factors undermining the quality of life in geriatric patients. Although the WHO has declared 'Dementia' as a priority health condition.Cognitive neuropharmacology is still in its infancy and there is no general consensus on the use of cognition enhancing (CE) drugs in humans. Since drug utilization data of CEs in dementia are scarce, we conducted a study to describe the observed patterns of CE drug use, compare it to the current recommendations and conduct a preliminary cost analysis.

METHODS

A prospective cross sectional drug utilization study of 100 prescriptions of patients of both sexes and all ages suffering from dementia attending the Neurology and Psychiatry clinics was undertaken as per the WHO - DUS and the STROBE guidelines.

RESULTS

In all, the 100 prescriptions contained 322 drugs, out of which, 168 were CE drugs. 38.2% of the drugs were prescribed by generic names. Donepezil, Memantine, Piracetam, Rivastigmine and Gallantamine were prescribed to 76%, 34%, 8%, 6% and 0%, respectively. The PDD/DDD ratio of Donepezil and Memantine were 1.36 and 0.94, respectively. The average cost per prescription was INR 626.29 or USD 9.5.

CONCLUSION

Principles of rational prescribing were followed. Donepezil and Memantine were the most commonly prescribed drugs and hence should be included in the hospital drug schedule. Piracetam should not be prescribed because of doubtful benefits and high cost. Antipsychotics should be used in geriatric dementia patients very judiciously. A major part of the total cost per prescription was borne by the patient.

Intracranial injection of PEG-PEI/ROCK II-siRNA improves cognitive impairment in a mouse model of Alzheimer's disease

PURPOSE

A plenty of studies have demonstrated that the Rho/ROCK pathway is involved in the neuronal loss and inhibition of axonal regeneration observed in Alzheimer's disease (AD). Therefore, we conducted this study to evaluate whether intracranial injection of PEG-PEI/ROCK II siRNA (PPRS) would improve the cognitive impairments in a senescence-accelerated mouse (SAM) model of AD.

MATERIALS AND METHODS

Five male senescence-resistant inbred strain (SAMR1) mice and 15 male senescence-accelerated mouse prone-8 (SAMP8) strain mice were divided into the following three groups:PPRS group, PEG-PEI/ ROCK II-Scramble (PPRScr) siRNA group, and normal group (SAMR1). Total volumes of 2.3 μl of nanoparticles or saline were intracranially injected under the guidance of a stereotaxic apparatus. The injections were performed every three days and lasted for two weeks. Four weeks after injection, the Morris water maze (MWM) was used to evaluate the spatial learning and memory functions of the mice. Choline acetyltransferase (ChAT) activity was detected by immunohistochemistry.

RESULTS

Mice in the PPRS-treated group exhibited decreases in escape latencies over the three successive days of navigating the test and crossing the target quadrant during the spatial probe test more frequently than did the mice in the PPRScr-treated group. Analyses of ChAT activity revealed that greater numbers of ChAT-positive cells were present in the hippocampal regions of the PPRS-treated mice than in the PPRScr group.

CONCLUSIONS

Intracranial injection of PPRS improved the cognitive impairments of SAM mice, and this improvement may have been mediated by enhancement of ChAT activity in the hippocampus.

In silico QSAR analysis of quercetin reveals its potential as therapeutic drug for Alzheimer's disease

Acetylcholine-esterase (AchE) inhibitors are one of the most potent drug molecules against Alzheimer's disease (AD). But, patients treated with current AchE inhibitors often experience severe side effects. Quercetin is a plant flavonoid compound which can act as AchE inhibitor and it may be a better alternative to current AchE inhibitors in terms of effectiveness with no or fewer side effects.

AIMS

The aim of the study was to compare quercetin with conventional AchE inhibitors to search for a better drug candidate.

METHODS AND MATERIALS

Physico-chemical properties of conventional drugs and quercetin were predicted using bioinformatics tools. Molecular docking of these compounds on the active site of AchE was performed using AutoDock and comparative analysis was performed. Later, modification on the basic structure of quercetin with different functional groups was done to perform QSAR analysis.

RESULT AND DISCUSSION

Quercetin showed a similar drug likeness score to the conventional drugs. The binding strength for quercetin in the active site of the enzyme was -8.8 kcal/mol, which was considerably higher than binding scores for some of the drugs such as donepezil (binding score -7.9 kcal/mol). Fifteen hydrogen bonds were predicted between quercetin and the enzyme whereas conventional drugs had fewer or even no hydrogen bonds. It implies that quercetin can act as a better inhibitor than conventional drugs. To find out even better inhibitor, similar structures of quercetin were searched through SIMCOMP database and a methylation in the 4-OH position of the molecule showed better binding affinity than parent quercetin. Quantitative structure activity relationship study indicated that O-4 methylation was specifically responsible for better affinity.

CONCLUSION

This in silico study has conclusively predicted the superiority of the natural compound quercetin over the conventional drugs as AchE inhibitor and it sets the need for further in-vitro study of this compound in future.

A literature review of spaced-retrieval interventions: a direct memory intervention for people with dementia

BACKGROUND

With the increasing prevalence of dementia, there is a pressing need to identify effective interventions that prolong independent functioning. As pharmacological interventions aimed at slowing cognitive decline have been found to have a number of limitations, research has now moved toward studying complementary non-pharmacological cognitive training interventions. This review describes the use of spaced-retrieval as a method to teach new information and reduce behavioral problems in people with dementia.

METHODS

We searched the databases PsychINFO, MEDLINE, and Scopus as well as reference lists of relevant papers to identify articles describing the use of spaced-retrieval with people with dementia. Only primary, peer-reviewed research published in English was included in this review.

RESULTS

In total, 34 studies were identified, three of which were randomized controlled trials. We found that across studies, there was wide variability with regard to design, methodology, and outcome measures used. Nonetheless, the existing research demonstrates that spaced-retrieval training can be successfully used to teach people with dementia new and previously known face- and object-name associations, as well as cue-behavior associations aimed at alleviating problem behaviors and improving functional skills. The method can also assist with the recollection of past events.

CONCLUSIONS

Current evidence indicates that spaced-retrieval training is effective in enabling people with dementia to learn new information and behavioral strategies. Future research should attempt to address the limitations outlined in this review and focus on utilizing this technique to achieve more functional and clinically relevant outcomes. Recommendations are also made with regard to investigating potential secondary benefits of spaced-retrieval and strengthening study design.

Structural study of piracetam polymorphs and cocrystals: crystallography redetermination and quantum mechanics calculations

Pharmaceutical compounds are mostly developed as solid dosage forms containing a single-crystal form. It means that the selection of a particular crystal state for a given molecule is an important step for further clinical outlooks. In this context, piracetam, a pharmaceutical molecule known since the sixties for its nootropic properties, is considered in the present work. This molecule is analyzed using several experimental and theoretical approaches. First, the conformational space of the molecule has been systematically explored by performing a quantum mechanics scan of the two most relevant dihedral angles of the lateral chain. The predicted stable conformations have been compared to all the reported experimental geometries retrieved from the Cambridge Structural Database (CSD) covering polymorphs and cocrystals structures. In parallel, different batches of powders have been recrystallized. Under specific conditions, single crystals of polymorph (III) of piracetam have been obtained, an outcome confirmed by crystallographic analysis.

Traditional used Plants against Cognitive Decline and Alzheimer Disease

Alzheimer's disease (AD) is a neurodegenerative disorder characterized clinically by progressive memory deficits, impaired cognitive function, and altered and inappropriate behavior. Aging represents the most important risk factor for AD and the global trend in the phenomenon of population aging has dramatic consequences for public health, healthcare financing, and delivery systems in the word and, especially in developing countries. Mounting evidence obtained in in vitro and in vivo studies, suggests that various traditionally used plants in Asia, India, and Europe significantly affect key metabolic alterations culminating in AD-typical neurodegeneration. The present article aims to bring the reader up-to-date on the most recent studies and advances describing the direct and indirect activities of traditional used plants and its constituents possibly relieving features of AD. A variety of traditional used plants and its extracts exerted activities on AD related drug targets including AChE activity, antioxidative activity, modulation of Aβ-producing secretase activities, Aβ-degradation, heavy metal chelating, induction of neurotrophic factors, and cell death mechanisms. Although pre-clinical investigations identified promising drug candidates for AD, clinical evidences are still pending.

Synthesis and biological evaluation of novel flavonoid derivatives as dual binding acetylcholinesterase inhibitors

A new series of flavonoid derivatives have been designed, synthesised and evaluated as acetylcholinesterase inhibitors that could bind simultaneously to the peripheral and catalytic sites of the enzyme. Among them, fifteen derivatives were found to inhibit the enzyme in the micromolar range and isoflavone derivatives possessed more potent inhibitory activity than other flavonoid derivatives. The best compound 9a had its inhibitory activity (IC(50) = 0.093 microM) in the same range as the reference compound, donepezil (IC(50) = 0.025 microM). Preliminary structure-activity relationships and a molecular modeling study for 9a have revealed that the isoflavone moiety plays a key role in the interaction of this series of derivatives with AChE by acting as an anchor in its peripheral anionic site.

From nose to brain: understanding transport capacity and transport rate of drugs

The unique relationship between nasal cavity and cranial cavity tissues in anatomy and physiology makes intranasal delivery to the brain feasible. An intranasal delivery provides some drugs with short channels to bypass the blood-brain barrier (BBB), especially for those with fairly low brain concentrations after a routine delivery, thus greatly enhancing the therapeutic effect on brain diseases. In the past two decades, a good number of encouraging outcomes have been reported in the treatment of diseases of the brain or central nervous system (CNS) through nasal administration. In spite of the significant merit of bypassing the BBB, direct nose-to-brain delivery still bears the problems of low efficiency and volume for capacity due to the limited volume of the nasal cavity, the small area ratio of olfactory mucosa to nasal mucosa and the limitations of low dose and short retention time of drug absorption. It is crucial that selective distribution and retention time of drugs or preparations on olfactory mucosa should be enhanced so as to increase the direct delivery efficiency. In this article, we first briefly review the nose-to-brain transport pathways, before detailing the impacts on them, followed by a comprehensive summary of effective methods, including formulation modification, agglutinant-mediated transport and a brain-homing, peptide-mediated delivery based on phage display screening technique, with a view to providing a theoretic reference for elevating the therapeutic effects on brain diseases.

Quality of life and cholinesterase inhibitors: a qualitative study of patients with Alzheimer's disease and their carers

OBJECTIVES

Cholinesterase inhibitors' (ChEIs) impact on cognitive functioning in Alzheimer's disease has been extensively researched. The effect of ChEIs on improving day-to-day living and quality of life in conjunction with level of functioning for patients or their carers has not been investigated.

METHOD

Five spouse dyads (patient and carer) and one additional carer were interviewed about their perceptions of ChEIs in relation to their influence on daily life for both parties. Interviews were transcribed and thematic analysis conducted.

RESULTS

Themes identified were forgetfulness, differences in long-term versus short-term memory, independence/dependence, negative emotion, no appreciable benefit, sense of hopelessness, carer as motivator, stabilization of the patient, and never regain what has been lost.

CONCLUSIONS

This study suggests that ChEI medication does not enhance life for the patient or their primary caregiver. Further qualitative and quantitative research is required into the impact of ChEIs upon both the patient and their caregivers.

Inhibition of acetylcholinesterase by two arylderivatives: 3a-Acetoxy-5H-pyrrolo(1,2-a) (3,1)benzoxazin-1,5-(3aH)-dione andcis-N-p-Acetoxy-phenylisomaleimide

Two arylderivatives, 3a-Acetoxy-5H-pyrrolo(1,2-a) (3,1)benzoxazin-1,5-(3aH)-dione 3 and cis-N-p-Acetoxy-phenylisomaleimide 4, were synthesized from anthranilic acid and para-aminophenol, respectively. The inhibitory effects of these compounds on acetylcholinesterase (AChE) activity were evaluated in vitro as well as by docking simulations. Both compounds showed inhibition of AChE activity (Ki = 4.72 +/- 2.3 microM for 3 and 3.6 +/- 1.8 microM for 4) in in vitro studies. Moreover, they behaved as irreversible inhibitors and made pi-pi interaction with W84 and hydrogen bonded with S200 and Y337 according to experimental data and docking calculations. The docking calculations showed deltaG bind (kcal/mol) of - 9.22 for 3 and - 8.58 for 4. These two compounds that can be use as leads for a new family of anti-Alzheimer disease drugs.

Errorless learning and spaced retrieval techniques to relearn instrumental activities of daily living in mild Alzheimer's disease: A case report study

Previous studies on cognitive training in Alzheimer's disease (AD) were principally aimed at making patients learn items not related to functional needs. However, AD patients also experience difficulties with instrumental activities of daily living (IADL). The goal of the present multiple baseline case report study was to assess the preliminary efficacy and tolerability of an individualized cognitive training program using the errorless learning (EL) and spaced-retrieval (SR) techniques to relearn forgotten IADLs in mild AD. Following an exhaustive neuropsychological assessment, two participants received two training sessions per week during four weeks. Participant A was trained to use his voice mail and Participant B, to manage the messages from his answering machine. The results showed that the program was well tolerated and improved performance on the trained tasks. These ameliorations were maintained over a 5-week period. The effects of the training did not have any impact on global cognitive functions since the results on these measures remained relatively stable. This case report demonstrated preliminary efficacy of a new cognitive training program using EL and SR techniques tailored to the needs of AD patients. This is an important finding since the loss of these capacities alters autonomy in AD patients.

Potential medicinal plants for CNS disorders: an overview

Although very few drugs are currently approved by regulatory authorities for treating multi-factorial ailments and disorders of cognition such as Alzheimer's disease, certain plant-derived agents, including, for example, galantamine and rivastigmine (a semi-synthetic derivative of physostigmine) are finding an application in modern medicine. However, in Ayurveda, the Indian traditional system of medicine which is more than 5000 years old, selected plants have long been classified as 'medhya rasayanas', from the Sanskrit words 'medhya', meaning intellect or cognition, and 'rasayana', meaning 'rejuvenation'. These plants are used both in herbal and conventional medicine and offer benefits that pharmaceutical drugs lack. In the present article, an attempt has been made to review the most important medicinal plants, including Ginkgo biloba, St John's wort, Kava-kava, Valerian, Bacopa monniera and Convolvulus pluricaulis, which are widely used for their reputed effectiveness in CNS disorders.

Treatment of cognitive impairment in multiple sclerosis: is the use of acetylcholinesterase inhibitors a viable option?

Approximately half of all patients with multiple sclerosis (MS) experience cognitive impairment, most commonly with regard to new learning and memory. Cognitive dysfunction is a leading cause of disability in MS and it can have profound social and economic consequences for patients and their families. Research on treatment for cognitive impairment in MS is still in the early stages, as it is for most neurological conditions. The available disease-modifying therapies in MS may provide some modest benefit to cognition, but patients with MS clearly need better treatment for cognitive dysfunction. A number of studies have assessed symptomatic treatments of cognition in MS, and the results of these small, underpowered studies have been mixed. Regardless, acetylcholinesterase inhibitors (AChEIs) have been the most promising class of medications tested in MS to date. Seven of eight studies on AChEIs have shown positive results, although it is difficult to assess their adequacy since only three of the studies have been published in peer reviewed journals, with the rest appearing only as abstracts. The earliest AChEI studies in MS examined physostigmine, but the short half-life and prominent adverse effects of this medication may have limited its use compared with other AChEIs. All of the more recent AChEI studies have used donepezil, which, from the limited data available to date, appears to have been relatively well tolerated among MS patients. The largest randomized controlled trial of donepezil included 69 subjects and found that donepezil improved verbal learning and memory compared with placebo during neuropsychological testing. That study also found that patients receiving donepezil were more likely to report memory improvement than those receiving placebo, and the study clinician also noted a cognitive benefit among those on donepezil as opposed to placebo. There are still many unanswered questions regarding the use of AChEIs in MS, including the effects of their long-term use in a chronic disease such as MS. On the whole, to date the research on AChEIs in MS must be considered preliminary, and it is premature to recommend the clinical use of this class of medications at the present time.

Detection of amyloid beta protein in the urine of Alzheimer's disease patients and healthy individuals

To seek for a new valid biomarker using non-invasive specimens for the diagnosis of Alzheimer's disease (AD) and mild cognitive impairment (MCI), we carried out the detection of amyloid beta (Abeta) protein in urine. Ten-millilitre urine samples were first sedimented with trichloroacetic acid, and the pellets were resuspended for further analysis by Western blotting with anti-Abeta antibody. The detection sensitivity of the method was 40pg/ml. Rates of subjects positive for monomeric Abeta according to their clinical dementia rating (CDR) were 11.1% for CDR 0, 62.5% for CDR 0.5, 83.3% for CDR 1, 54.5% for CDR 2 and 0% for CDR 3. A single Abeta band relative to the CDR score reflects an alteration in the production, solubility and clearance of Abeta in the brain. Thus, the method could be used as both a diagnostic and monitoring tool in assessing AD and MCI patients during disease-modifying therapies.

Is long-term treatment of Alzheimer's disease with cholinesterase inhibitor therapy justified?

The cholinesterase inhibitors (ChEIs) donepezil, rivastigmine and galantamine are the current mainstays in the drug treatment of Alzheimer's disease (AD). There is convincing evidence that these agents provide at least modest cognitive, behavioural and functional benefit for 6-12 months at all stages of the disease. Longer term benefits cannot be directly examined by placebo-controlled trials. Nevertheless, the results of virtually all open-label extensions of the pivotal trials, studies of patients with AD at different levels of severity and clinical trials using other designs favour treatment over no treatment for periods of up to 5 years. There are plausible biological reasons why ChEIs might be expected to work over a prolonged period of time although, to date, studies using various markers to chart the effects of medication on long-term disease progression have yielded mixed results. The most contentious issue regarding long-term treatment is economic, but the majority of available economic analyses suggest net savings over the long term if patients with AD receive persistent treatment with ChEIs.

Moving toward Medicare home health coverage for persons with Alzheimer's disease

Medicare home health care policy does not incorporate research evidence of effective palliative home care interventions for Alzheimer's disease and dementia patients and caregivers. This article examines the dissonance between the needs and burdens of Alzheimer's disease patients and caregivers, research results on medical and palliative care interventions, and medicalized public policy in the Medicare home health benefit. The article asserts existing research establishes a prima facie case exists for the federal government to fund a Medicare Palliative Home Care for Alzheimer's disease demonstration project. The article cites the success of the Medicare Hospice Demonstration project and Hospice Medicare Benefit in reducing costs and improving client quality of life as precedent and a model for Alzheimer's disease. Other research implications are identified.

Pharmacogenomics in Alzheimer's disease

Pharmacological treatment in Alzheimer's disease (AD) accounts for 10-20% of direct costs, and fewer than 20% of AD patients are moderate responders to conventional drugs (donepezil, rivastigmine, galantamine, memantine), with doubtful cost-effectiveness. Both AD pathogenesis and drug metabolism are genetically regulated complex traits in which hundreds of genes cooperatively participate. Structural genomics studies demonstrated that more than 200 genes might be involved in AD pathogenesis regulating dysfunctional genetic networks leading to premature neuronal death. The AD population exhibits a higher genetic variation rate than the control population, with absolute and relative genetic variations of 40-60% and 0.85-1.89%, respectively. AD patients also differ in their genomic architecture from patients with other forms of dementia. Functional genomics studies in AD revealed that age of onset, brain atrophy, cerebrovascular hemodynamics, brain bioelectrical activity, cognitive decline, apoptosis, immune function, lipid metabolism dyshomeostasis, and amyloid deposition are associated with AD-related genes. Pioneering pharmacogenomics studies also demonstrated that the therapeutic response in AD is genotype-specific, with apolipoprotein E (APOE) 4/4 carriers the worst responders to conventional treatments. About 10-20% of Caucasians are carriers of defective cytochrome P450 (CYP) 2D6 polymorphic variants that alter the metabolism and effects of AD drugs and many psychotropic agents currently administered to patients with dementia. There is a moderate accumulation of AD-related genetic variants of risk in CYP2D6 poor metabolizers (PMs) and ultrarapid metabolizers (UMs), who are the worst responders to conventional drugs. The association of the APOE-4 allele with specific genetic variants of other genes (e.g., CYP2D6, angiotensin-converting enzyme [ACE]) negatively modulates the therapeutic response to multifactorial treatments affecting cognition, mood, and behavior. Pharmacogenetic and pharmacogenomic factors may account for 60-90% of drug variability in drug disposition and pharmacodynamics. The incorporation of pharmacogenetic/pharmacogenomic protocols to AD research and clinical practice can foster therapeutics optimization by helping to develop cost-effective pharmaceuticals and improving drug efficacy and safety.

Prescription patterns and efficacy of drugs for patients with dementia: physicians' perspective in Italy

BACKGROUND AND AIMS

The aim of this study was to assess the prescription practices and judgment of efficacy of physicians of drugs used for the cognitive and non-cognitive symptoms of dementia.

METHODS

Physicians from 88 Italian Alzheimer Evaluation Units were surveyed by means of a structured questionnaire assessing the proportion of patients with four different types of dementia prescribed with drugs for cognitive and non-cognitive symptoms, and physicians' perceived efficacy of cholinesterase inhibitors. The Units prescribed cholinesterase inhibitors for 73 patients per year on average.

RESULTS

Cholinesterase inhibitors are prescribed to 90% of patients with Alzheimer's disease (AD), 80% with with Lewy body dementia (LBD), and 35-45% with vascular dementia (VD) and frontotemporal lobar degeneration (FTLD). Selective serotonin uptake inhibitors (SSRIs) are prescribed for 28-45% of patients with all dementias except LBD (16%). Atypical neuroleptics were prescribed for 23-31% of patients, with no difference across types of dementia. Other drugs, such as ginkgo and nootropics, were prescribed less frequently, except in VD (20%). The perceived efficacy on cognitive and non-cognitive symptoms, assessed on a 0-to-10 ordinal scale, was highest in AD (4.3-6.1), intermediate in LBD (3.5-5.3) and VD (3.3- 4.7), and lowest in FTLD (2.0-2.7).

CONCLUSIONS

The data indicate that, in specialized Italian centers, cholinesterase inhibitors and atypical neuroleptics are largely used in patients with AD and LBD, but the former are prescribed off-label to a remarkable proportion of patients with VD and FTLD. The efficacy of cholinesterase inhibitors is perceived to be highest in AD and poorest in FTLD. Perceived efficacy is affected more by whom is treated than by what is used.

Motor-skill learning in Alzheimer's disease: a review with an eye to the clinical practice

Since elderly people suffering from dementia want to go on living independently for as long as possible, they need to be able to maintain familiar and learn new practical skills. Although explicit or declarative learning methods are mostly used to train new skills, it is hypothesized that implicit or procedural techniques may be more effective in this population. The present review discusses 23 experimental studies on implicit motor-skill learning in patients with Alzheimer's disease (AD). All studies found intact implicit motor-learning capacities. Subsequently, it is elaborated how these intact learning abilities can be exploited in the patients' rehabilitation with respect to the variables 'practice' and 'feedback.' Recommendations for future research are provided, and it is concluded that if training programs are adjusted to specific needs and abilities, older people with AD are well able to (re)learn practical motor skills, which may enhance their autonomy.

The nootropic and neuroprotective proline-containing dipeptide noopept restores spatial memory and increases immunoreactivity to amyloid in an Alzheimer's disease model

The effects of the novel proline-containing nootropic and neuroprotective dipeptide, noopept (GVS-111, N-phenylacetyl-L-prolylglycine ethyl ester) were investigated in NMRI mice following olfactory bulbectomy. We have shown previously that these animals developed Alzheimer's disease (AD)-like behaviour, morphology and biochemistry including impairment of spatial memory, regional neuronal degeneration and elevated Abeta peptide brain levels. In the current investigation, spatial memory was assessed using the Morris water maze and serum antibodies to in vitro morphologically characterized amyloid structures of both Abeta((25-35)) peptide and equine lysozyme, as well as to neurotrophic glial factor S100b, were analyzed by enzyme-linked immunosorbent assay (ELISA). Noopept (administered at a dose of 0.01 mg/kg for a period of 21 days and during a further 5 days training) restored spatial memory and increased serum antibody levels to oligomers of Abeta((25-35)) peptide but not to equine lysozyme amyloid or S100b protein in bulbectomized animals. The positive immunotropic effect of noopept to Abeta((25-35)) peptide prefibrillar aggregates was more marked in sham-operated compared to the bulbectomized subjects which were characterized by an overall suppression of immunoreactivity. Enhancement of the immune response to Abeta((25-35)) peptide prefibrils caused by noopept may attenuate the neurotoxic consequences of amyloid fibrillization and also be associated with an improvement in spatial memory in bulbectomized mice. These actions of noopept, combined with its previously reported neuroprotective and cholinomimetic properties, suggests that this dipeptide may well be useful for improving cognitive deficits induced by neurodegenerative diseases.

Functional outcomes of drug treatment in Alzheimer's disease: A systematic review and meta-analysis

BACKGROUND

Patient functioning is an important outcome in Alzheimer's disease, but treatment-related improvements in patient function are difficult to quantify because a number of different scales are used in its measurement.

OBJECTIVE

To evaluate systematically the evidence relating to patient functioning as an outcome measure in the drug treatment of Alzheimer's disease. Data were obtained by searching MEDLINE, EMBASE, The Cochrane Library and the International Pharmaceutical Abstracts from 1980 through to December 2005 for studies assessing functional outcomes with donepezil, galantamine, rivastigmine and memantine in Alzheimer's disease. Reference lists were searched manually and pharmaceutical manufacturers were invited to submit dossiers. Trained reviewers abstracted data and assessed the internal validity (quality) of trials using predefined criteria. Standardised effect sizes (i.e. Cohen's standardised mean difference [d]) for various functional outcome scales and pooled mean incidence and 95% CIs for adverse events were calculated and summarised qualitatively and quantitatively. Meta regression was used to explore potential heterogeneity.

RESULTS

Overall, the standardised effect size for functional outcome measures was small (d = 0.1-0.4) among included studies. However, effect sizes consistently favoured drug treatment over placebo. For all drugs, pooled standardised effect sizes were consistent in both short (<24 weeks; d = 0.25; 95% CI 0.13, 0.37) and long trials (>or=24 weeks; d = 0.29; 95% CI 0.22, 0.36). The pooled effect size was not significantly affected by parameters such as disease severity, age, gender and drug dose. Adverse events were generally limited to gastrointestinal problems, weight loss and dizziness, all of which were reported in <20% of patients on average.

CONCLUSIONS

Standardised estimates of effect size across diverse functional outcome measures for drug treatment in patients with Alzheimer's disease were small and the data reflect only a modest trend favouring active treatment over placebo. However, given the current lack of other effective treatments for Alzheimer's disease, this trend supports the clinical benefits of these treatments with regard to this important health outcome.

Short latency afferent inhibition is not impaired in mild cognitive impairment

OBJECTIVE

To determine whether cortical cholinergic circuit impairment exists in the mild cognitive impairment (MCI) brain.

METHODS

Fifteen healthy elderly controls (NC), 16 amnesic MCI subjects and 12 probable Alzheimer's disease (AD) subjects were recruited. Conditioning stimuli were delivered at the right wrist followed by test transcranial magnetic stimulation (TMS) of the left motor cortex. The center of the linear contiguous segment of the coil was placed over a point 5 cm lateral to the vertex on the interaural line. The interstimulus intervals (ISIs) between the conditioning stimuli and the test stimuli were set at 20, 40, 100, 200 and 600 ms. An inhibitory effect that occurred at ISIs as short as 20 ms was defined as short-latency afferent inhibition (SAI).

RESULTS

SAI was significantly reduced in subjects with AD compared with NC, but it was not reduced in subjects with MCI.

CONCLUSIONS

A difference in cortical excitability between subjects with AD and subjects with MCI could be captured by an in vivo neurophysiological method.

SIGNIFICANCE

The state of the neurotransmitter systems, including the cortical cholinergic system, is thought by some compensatory mechanisms to be kept at the normal level in subjects with MCI.

In vitro formulation optimization of intranasal galantamine leading to enhanced bioavailability and reduced emetic response in vivo

The purpose of the current investigation was to optimize an intranasal (IN) galantamine (an acetylcholinesterase inhibitor used for treatment of Alzheimer's disease) formulation using an in vitro tissue model, to correlate those results to in vivo bioavailability, and to compare emetic response to oral dosing. A design-of-experiments (DOE) based formulation screening employing an in vitro tissue model of human nasal epithelium was used to assess drug permeability, tight junction modulation, and cellular toxicity. In vivo studies in rats compared pharmacokinetic (PK) profiles of different formulations dosed intranasally. Finally, studies in ferrets evaluated PK and gastrointestinal (GI) related side effects of oral compared to nasal dosage forms. Galantamine permeation was enhanced without increasing cytotoxicity. Pharmacokinetic testing in rats confirmed the improved drug bioavailability and demonstrated an in vitro-in vivo correlation. Compared to oral dosing, IN galantamine resulted in a dramatically lowered incidence of GI-related side effects, e.g., retching and emesis. These findings illustrate that IN delivery represents an attractive alternative to oral dosing for this important Alzheimer's disease therapeutic. To our knowledge, the data herein represent the first direct confirmation of reducing GI-related side effects for IN galantamine compared to oral dosing.

Wirksam, indiziert - und dennoch ohne Nutzen?

Individual treatment decisions for patients with Alzheimer dementia are often characterized by uncertainty about the actual benefit that specific treatments or procedures may bring about. It often even remains unclear how the benefit of a treatment may be determined. In this paper, three criteria for determining the benefit of a treatment measure are developed: An intervention (1) must be effective and (2) able to achieve a clinically relevant goal, which is (3) desirable for the individual patient. By using example of anti-dementia drug treatment, it will by shown that even if standard goals of dementia care are achieved, the benefit for the patient may still be questionable. A cognitive improvement or a delay of cognitive decay may even harm the patient. Therefore it is not sufficient to focus on the efficacy of a drug and on general goals of care when making decisions about individual dementia treatments. Rather it is necessary to reflect and discuss explicitly the goals of the individual patient. As shown by various examples, this will facilitate coherent, patient-orientated treatment decisions.

The spice sage and its active ingredient rosmarinic acid protect PC12 cells from amyloid-beta peptide-induced neurotoxicity

Traditional use and clinical reports suggest that the culinary herb sage (Salvia officinalis) may be effective for patients with mild to moderate Alzheimer's disease (AD). In this study, we evaluated the effect of a standardized extract from the leaves of S. officinalis (SOE) and its active ingredient rosmarinic acid on Alzheimer amyloid-beta peptide (Abeta)-induced toxicity in cultured rat pheochromocytoma (PC12) cells. Incubation of PC12 cells with Abeta (fragment 1-42) for 24 h caused cell death, and this effect was reduced by SOE and its active ingredient, rosmarinic acid. Rosmarinic acid reduced a number of events induced by Abeta. These include reactive oxygen species formation, lipid peroxidation, DNA fragmentation, caspase-3 activation, and tau protein hyperphosphorylation. Moreover, rosmarinic acid inhibited phosphorylated p38 mitogen-activated protein kinase but not glycogen synthase kinase 3beta activation. These data show the neuroprotective effect of sage against Abeta-induced toxicity, which could validate the traditional use of this spice in the treatment of AD. Rosmarinic acid could contribute, at least in part, for sage-induced neuroprotective effect.

Effects of donepezil on memory and cognition in multiple sclerosis

Acetylcholinesterase inhibitors are used to treat dementia associated with Alzheimer's disease, but their cognitive benefits may extend to additional disorders such as multiple sclerosis (MS). A single-center double-blind placebo-controlled randomized clinical trial evaluated the effectiveness of donepezil in a sample of 69 MS persons selected for initial memory difficulties. Subjects received neuropsychological assessment at baseline and after 24 weeks of treatment. The primary outcome was change in total recall on the Selective Reminding Test, a measure of verbal learning and memory. Secondary outcomes included other neuropsychological tests from the Brief Repeatable Battery, patient-reported change in memory, and physician-reported impression of cognitive change. Donepezil improved memory performance on the SRT compared to placebo. This benefit remained significant after controlling for various covariates including Expanded Disability Status Scale (EDSS), MS subtype, interferon beta use, treatment group beliefs, gender, baseline selected reminding test (SRT) score, and reading ability. Subjects on donepezil were more likely to report memory improvement (65.7%) than those on placebo (32.4%). The clinician also reported cognitive improvement in more donepezil (54.3%) than placebo (29.4%) subjects. No serious adverse events related to study medication occurred. However, more donepezil (34.3%) than placebo (8.8%) subjects reported unusual/abnormal dreams. Donepezil improved learning and memory in MS patients with initial cognitive difficulties in a single-center clinical trial. Replication of results in a larger multi-center investigation is warranted in order to more definitively assess the efficacy of this intervention.

The relevance of pharmacokinetic studies in designing efficacy trials in juvenile major depression

INTRODUCTION

Identifying evidence-based dosing strategies is a key part of new drug development in pediatric populations. Pharmacokinetic (PK) studies can provide important information regarding how best to dose medications in children and adolescents. Utilizing scientifically supported dosing strategies provides the best chance for any given drug to demonstrate both efficacy and acceptable tolerability in definitive, placebo-controlled studies.

METHODS

Results of both PK studies and randomized, placebo-controlled efficacy trials (RPCTs) in juvenile major depressive disorder (MDD) are reviewed. The degree to which the medication dosing strategies that were employed in the efficacy studies were supported by the extant PK data is considered. Medications that are reviewed include fluoxetine, sertraline, paroxetine, citalopram, escitalopram, venlafaxine, nefazodone, and mirtazapine.

RESULTS

In many instances, the dosing paradigms that were used in the RPCTs differed, sometimes substantially, from the dosing strategies that would have been supported based on the results of PK studies.

CONCLUSIONS

Medication dosing regimens may have contributed to the failure of several RPCTs to show drug efficacy in the treatment of pediatric MDD. In addition, the doses of medication used in these RPCTs may also have contributed to the safety and tolerability concerns that have been raised with these drugs. PK and dose-ranging studies should be performed prior to the initiation of definitive efficacy trials so that empirically supported dosing strategies can be incorporated into the design of RPCTs of antidepressants in children and adolescents suffering from MDD.

Novel Tacrine−Melatonin Hybrids as Dual-Acting Drugs for Alzheimer Disease, with Improved Acetylcholinesterase Inhibitory and Antioxidant Properties

Tacrine and melatonin are well-known drugs with activities as an acetylcholinesterase (AChE) inhibitor and free radical scavenger, respectively. In this work, we report new hybrids of both drugs that display higher in vitro properties than the sum of their parts. As selective inhibitors of human AChE, their IC(50) values range from sub-nanomolar to picomolar. They exhibit a higher oxygen radical absorbance capacity than does melatonin and are predicted to be able to cross the blood-brain barrier to reach their targets in the central nervous system.

Design and synthesis of N-benzylpiperidine–purine derivatives as new dual inhibitors of acetyl- and butyrylcholinesterase

The synthesis and biological evaluation of N-benzyl-(piperidin or pyrrolidin)-purines are described. Compounds derived from N-benzylpiperidine and N-substituted purines showed moderate acetylcholinesterase inhibition. Preliminary structure-activity relationships and a superimposition of the best compound with the active conformation of donepezil have revealed structural features that have been used in the design of more potent N-benzylpiperidine inhibitors bearing an 8-substituted caffeine fragment and a methoxymethyl linker. These new compounds are interesting dual inhibitors of acetylcholinesterase and butyrylcholinesterase and have been chosen for further optimisation.

Vitamin E supplementation in Alzheimer's disease, Parkinson's disease, tardive dyskinesia, and cataract: Part 2

OBJECTIVE

To review clinical trials evaluating the safety and efficacy of vitamin E supplementation in Alzheimer's disease, Parkinson's disease, tardive dyskinesia, and cataract.

DATA SOURCES

Using the MeSH terms alpha-tocopherol, tocopherols, vitamin E, Parkinson disease, tardive dyskinesia, Alzheimer disease, cataract, and clinical trials, a literature review was conducted to identify peer-reviewed articles in MEDLINE (1966-July 2005).

STUDY SELECTION AND DATA EXTRACTION

Published materials including original research, review articles, and meta-analyses were reviewed. Only English-language articles and trials that included vitamin E alone or in combination with other vitamins or minerals were reviewed. Emphasis was placed on prospective, randomized, double-blind, placebo-controlled clinical trials.

DATA SYNTHESIS

The clinical studies demonstrated contradicting results regarding the benefits of vitamin E in Parkinson's disease, tardive dyskinesia, and cataract. The study reviewed for Alzheimer's disease seemed to show benefit when vitamin E was used; however, the statistical methods employed are questionable. There is enough evidence from large, well-designed studies to discourage the use of vitamin E in Parkinson's disease, cataract, and Alzheimer's disease. We recommend that vitamin E be considered a treatment option in patients with tardive dyskinesia only if they are newly diagnosed.

CONCLUSIONS

We encourage patients to supplement with vitamin E-rich foods. The use of a daily multivitamin, which usually contains 30 IU of alpha-tocopherol, may be beneficial; however, we discourage individual vitamin E supplements that usually contain 400 IU of alpha-tocopherol.