Increased Alzheimer pathology in Parkinson's disease related to antimuscarinic drugs

Associations Between Midlife Anticholinergic Medication Use and Subsequent Cognitive Decline: A British Birth Cohort Study

BACKGROUND

Anticholinergic medication use is associated with cognitive decline and incident dementia. Our study, a prospective birth cohort analysis, aimed to determine if repeated exposure to anticholinergic medications was associated with greater decline, and whether decline was reversed with medication reduction.

METHODS

From the Medical Research Council (MRC) National Survey of Health and Development, a British birth cohort with all participants born in a single week of March 1946, we quantified anticholinergic exposure between ages 53 and 69 years using the Anticholinergic Cognitive Burden Scale (ACBS). We used multinomial regression to estimate associations with global cognition, quantified by the Addenbrooke's Cognitive Examination, 3rd Edition (ACE-III). Longitudinal associations between ACBS and cognitive test results (Verbal memory quantified by the Word Learning Test [WLT], and processing speed quantified by the Timed Letter Search Task [TLST]) at three time points (age 53, 60-64 and 69) were assessed using mixed and fixed effects linear regression models. Analyses were adjusted for sex, childhood cognition, education, chronic disease count and severity, and mental health symptoms.

RESULTS

Anticholinergic exposure was associated cross-sectionally with lower ACE-III scores at age 69, with the greatest effects in those with high exposure at ages 60-64 (mean difference - 2.34, 95% confidence interval [CI] - 3.51 to - 1.17). Longitudinally, both mild-moderate and high ACBS scores were linked to lower WLT scores, again with high exposure showing larger effects (mean difference with contemporaneous exposure - 0.90, 95% CI - 1.63 to - 0.17; mean difference with lagged exposure - 1.53, 95% CI - 2.43 to - 0.64). Associations remained in fixed effects models (mean difference with contemporaneous exposure -1.78, 95% CI -2.85 to - 0.71; mean difference with lagged exposure - 2.23, 95% CI - 3.33 to - 1.13). Associations with TLST were noted only in isolated contemporaneous exposure (mean difference - 13.14, 95% CI - 19.04 to - 7.23; p < 0.01).

CONCLUSIONS

Anticholinergic exposure throughout mid and later life was associated with lower cognitive function. Reduced processing speed was associated only with contemporaneous anticholinergic medication use, and not historical use. Associations with lower verbal recall were evident with both historical and contemporaneous use of anticholinergic medication, and associations with historical use persisted in individuals even when their anticholinergic medication use decreased over the course of the study.

Chronic high-dose dimenhydrinate use contributing to early multifactorial cognitive impairment

Dimenhydrinate is an over-the-counter antihistaminergic medication with anticholinergic properties used to treat nausea or motion sickness worldwide. There is a well-established correlation between the use of anticholinergic medications and dementia, however, it is unclear if a causal role exists. We report a case of minor neurocognitive disorder in a woman in her 40s with several years of high-dose daily dimenhydrinate abuse who subsequently developed significant delusional beliefs. Her clinical presentation was confounded by numerous other factors that could have impacted her cognition, such as a longstanding presumed learning disability, ankylosing spondylitis with adalimumab treatment, extensive cannabis use or potential development of a primary psychotic disorder. Her workup was within normal limits, and she has not responded to first-line antipsychotic medications to date. This case report adds to the growing evidence supporting concerns about potentially irreversible cognitive deficits in chronic misuse of anticholinergic agents, an association previously observed only in the elderly population.

Recommendations for a paradigm shift in approach to increase the recognition and treatment of sialorrhea in Parkinson's disease

Sialorrhea, or drooling, is defined as excessive saliva accumulation and unwanted loss of saliva from the mouth or over the tongue and into the pharynx. It constitutes one of the most frequent and bothersome complaints of patients with Parkinson's disease (PD), affecting up to 84% of them. Sialorrhea is a distressing and challenging condition that may result in social isolation, embarrassment, depression, skin infections, poor oral health, and aspiration pneumonia. To better understand the burden of sialorrhea on patients with PD, Parkinson's Europe carried out a worldwide patient survey which showed that sialorrhea remains an underrecognized and undertreated issue in patients with PD. This is especially problematic because effective therapeutic options are available. This article presents the results of the Parkinson's Europe Sialorrhea Survey, which were considered by a multidisciplinary panel of experts to provide recommendations for improving the awareness, diagnosis, management, and treatment of sialorrhea in patients with PD. A shift in the treatment paradigm for sialorrhea in patients with PD is emerging. It is essential to better educate patients, family members, caregivers, and healthcare professionals about sialorrhea; to engage all those involved to actively discuss sialorrhea and measure its impact on quality of life; and to recognize the role of botulinum toxin and speech and language therapy as first-line therapies.

Comparative safety of antimuscarinics versus mirabegron for overactive bladder in Parkinson disease

BACKGROUND

Overactive bladder (OAB) is a common non-motor symptom of Parkinson disease (PD), often treated with antimuscarinics or beta-3 agonists. There is lack of evidence to guide OAB management in PD.

OBJECTIVES

To assess the comparative safety of antimuscarinics versus beta-3 agonists for OAB treatment in PD.

METHODS

We employed a new-user, active-comparator cohort study design. We included Medicare beneficiaries age ≥65 years with PD who were new users of either antimuscarinic or beta-3 agonist. The primary outcome was any acute care encounter (i.e., non-elective hospitalization or emergency department visit) within 90 days of OAB drug initiation. The main secondary outcome was a composite measure of acute care encounters for anticholinergic related adverse events (AEs). Matching on high-dimensional propensity score (hdPS) was used to address potential confounding. We used Cox proportional hazards models to examine the association between OAB drug category and outcomes. We repeated analyses for 30- and 180-day follow-up periods.

RESULTS

We identified 27,091 individuals meeting inclusion criteria (mean age: 77.8 years). After hdPS matching, antimuscarinic users had increased risks for any acute care encounter (hazard ratio [HR] 1.23, 95% confidence interval [CI] 1.12-1.37) and encounters for anticholinergic related AEs (HR 1.18, 95% CI 1.04-1.34) compared to beta-3 agonist users. Similar associations were observed for sensitivity analyses.

CONCLUSIONS

Among persons with PD, anticholinergic initiation was associated with a higher risk of acute care encounters compared with beta-3 agonist initiation. The long-term safety of anticholinergic vs. beta-3 agonist therapy in the PD population should be evaluated in a prospective study.

Anticholinergic Drug Burden and Risk of Incident MCI and Dementia: A Population-based Study

OBJECTIVE

We investigated whether anticholinergic drug use was related to developing mild cognitive impairment (MCI) or dementia in older adults at the population level.

METHODS

We used an Anticholinergic Rating (ACR) scale, Clinical Dementia Rating, APOE genotype, and number of prescription medications. We examined time to incident MCI and incident dementia in a population-based cohort (n=1959). We assessed whether developing MCI or dementia was associated with (1) any anticholinergic drug use, (2) total ACR score, or (3) number of anticholinergic drugs taken.

RESULTS

Taking any anticholinergic drug was significantly associated with higher risk of developing MCI; however, higher ACR score or higher number of anticholinergic drugs, compared with lower, were not associated with greater risk of developing MCI. We found no significant relationship between anticholinergic use and developing dementia. The relationship between anticholinergic use and cognitive outcome was not affected by APOE genotype.

CONCLUSIONS

Among cognitively normal older adults in a population-based sample, anticholinergic drug use is independently associated with subsequently developing MCI, but not dementia. Thus, anticholinergic drug use may influence risk of MCI that is nonprogressive to dementia and potentially be a modifiable risk factor for MCI.

Beauty of the beast: anticholinergic tropane alkaloids in therapeutics

Tropane alkaloids (TAs) are among the most valued chemical compounds known since pre-historic times. Poisonous plants from Solanaceae family (Hyoscyamus niger, Datura, Atropa belladonna, Scopolia lurida, Mandragora officinarum, Duboisia) and Erythroxylaceae (Erythroxylum coca) are rich sources of tropane alkaloids. These compounds possess the anticholinergic properties as they could block the neurotransmitter acetylcholine action in the central and peripheral nervous system by binding at either muscarinic and/or nicotinic receptors. Hence, they are of great clinical importance and are used as antiemetics, anesthetics, antispasmodics, bronchodilator and mydriatics. They also serve as the lead compounds to generate more effective drugs. Due to the important pharmacological action they are listed in the WHO list of essential medicines and are available in market with FDA approval. However, being anticholinergic in action, TA medication are under the suspicion of causing dementia and cognitive decline like other medications with anticholinergic action, interestingly which is incorrect. There are published reviews on chemistry, biosynthesis, pharmacology, safety concerns, biotechnological aspects of TAs but the detailed information on anticholinergic mechanism of action, clinical pharmacology, FDA approval and anticholinergic burden is lacking. Hence the present review tries to fill this lacuna by critically summarizing and discussing the above mentioned aspects.

Use of Benzodiazepines and Risk of Incident Dementia: A Retrospective Cohort Study

BACKGROUND

Previous findings regarding the association between benzodiazepine exposure and dementia have conflicted, though many have not accounted for anticholinergic exposure. The goal of this study was to evaluate the association of benzodiazepine exposure with the risk of developing dementia, accounting for the anticholinergic burden.

METHODS

Using a retrospective cohort design, we identified veterans 65 or older without dementia during a 10-year baseline period and then followed participants for 5 years to evaluate the risk of dementia diagnosis. The primary exposure was cumulative benzodiazepine exposure. Cox proportional hazards survival model was used to examine the association between benzodiazepine exposure and dementia, adjusting for anticholinergic burden and other demographic and clinical characteristics associated with increased dementia risk.

RESULTS

Of the 528 006 veterans in the study cohort, 28.5% had at least one fill for a benzodiazepine. Overall, 7.9% developed a diagnosis of dementia during the observation period. Compared to veterans with no exposure to benzodiazepines, the adjusted hazard ratios for dementia risk were 1.06 (95% confidence interval [CI] 1.02-1.10) for low benzodiazepine exposure, 1.05 (95% CI 1.01-1.09) for medium benzodiazepine exposure, and 1.05 (95% CI 1.02-1.09) for high benzodiazepine exposure.

CONCLUSIONS

Cumulative benzodiazepine exposure was minimally associated with increased dementia risk when compared with nonuse but did not increase in a dose-dependent fashion with higher exposure. Veterans with low benzodiazepine exposure had essentially the equivalent risk of developing dementia as veterans with high exposure. While benzodiazepines are associated with many side effects for older adults, higher cumulative use does not appear to increase dementia risk.

Andrade LA, Ferraz HB, Barbosa ER, Rieder CRDM, da Silva DJ, Chien HF, Capato T, Rosso AL, Souza Lima CF, Bezerra JMF, Nicaretta D, Povoas Barsottini OG, Godeiro-Júnior C, Broseghini Barcelos L, Gisbert Cury R, Spitz M, Azevedo Silva SMC, Della Colletta MV. Guidelines for Parkinson’s disease treatment: consensus from the Movement Disorders Scientific Department of the Brazilian Academy of Neurology - motor symptoms

ABSTRACT The treatment of Parkinson's disease (PD) is challenging, especially since it is considered highly individualized. The Brazilian Academy of Neurology has recognized the need to disseminate knowledge about the management of PD treatment, adapting the best evidence to the Brazilian reality. Thus, the main published treatment guidelines were reviewed based on the recommendations of group from the Movement Disorders Scientific Department of the Brazilian Academy of Neurology.

Anticholinergic medication burden and cognitive function in participants of the ASPREE study

STUDY OBJECTIVE

What is the association between anticholinergic burden and specific domains of cognitive function in older adults who are initially without major cognitive impairment?

DESIGN

Post-hoc analysis of longitudinal observational data from the ASPirin in Reducing Events in the Elderly (ASPREE) study.

PATIENTS

19,114 participants from Australia and the United States aged 70 years and older (65 years and older for US minorities) were recruited and followed for a median of 4.7 years. At enrollment, participants were free of known cardiovascular disease, major physical disability, or dementia.

MEASUREMENTS

Cognitive assessments administered at baseline and biennially at follow-up visits included the Modified Mini-Mental State examination (3MS), Hopkins Verbal Learning Test-Revised (HVLT-R) delayed recall, Controlled Oral Word Association Test (COWAT), and Symbol Digit Modalities Test (SDMT). Anticholinergic burden was calculated at baseline using the Anticholinergic Cognitive Burden (ACB) scale and grouped as scores of 0 (no burden), 1-2 (low to moderate), or 3+ (high).

MAIN RESULTS

Linear mixed effects models were used to assess the relationship between ACB score and cognition over time. After adjusting for sex, age, education, minority status, smoking status, hypertension, diabetes, depression, chronic kidney disease, country, and frailty, participants with a high ACB score had worse performance over time for 3MS (Adjusted [Adj] B=-0.092, P=0.034), HVLT-R delayed recall (Adj B=-0.104, P<0.001), COWAT (Adj B=-0.151, P<0.001), and SDMT (Adj B=-0.129, P=0.026), than participants with an ACB score of 0. A low to moderate ACB score was also associated with worse performance over time for HVLT-R delayed recall (Adj B=-0.037, P=0.007) and COWAT (Adj B=-0.065, P=0.003), compared to those with no ACB.

CONCLUSIONS

Anticholinergic burden predicts worse cognitive function over time in initially dementia-free older adults, particularly for executive function (COWAT) and episodic memory (HVLT-R).

Antimuscarinic Anticholinergic Medications in Parkinson Disease: To Prescribe or Deprescribe?

The relative importance of antimuscarinic anticholinergic medications for Parkinson's disease (PD) declined after the introduction of levodopa, such that anticholinergic medications are now much more likely to be prescribed for clinical indications other than parkinsonism. Recent studies have found an association between anticholinergic medication exposure and future risk of dementia in older individuals and those with PD. These findings provide a further reason to avoid the use of anticholinergic medications to treat motor symptoms of PD. More importantly, they raise the question of whether one of the goals of PD treatment should be to deprescribe all medications with anticholinergic properties, regardless of their indication, to reduce dementia risk. In this review, we discuss the use of anticholinergic medications in PD, the evidence supporting the association between anticholinergic medications and future dementia risk, and the potential implications of these findings for clinical care in PD.

The cognitive effect of anticholinergics for patients with overactive bladder

Overactive bladder (OAB) is often treated with medications that block the cholinergic receptors in the bladder (known as anticholinergics). The effect of this medication class on cognition and risk of dementia has been increasingly studied over the past 40 years after initial studies suggested that the anticholinergic medication class could affect memory. Short-term randomized clinical trials demonstrated that the administration of the anticholinergic oxybutynin leads to impaired memory and attention, and large, population-based studies showed associations between several different anticholinergic medications and dementia. However, trials involving anticholinergics other than oxybutynin have not shown such substantial effects on short-term cognitive function. This discordance in results between short-term cognitive safety of OAB anticholinergics and the long-term increased dementia risk could be explained by the high proportion of patients using oxybutynin in the OAB subgroups of the dementia studies, or a study duration that was too short in the prospective clinical trials on cognition with other OAB anticholinergics. Notably, all studies must be interpreted in the context of potential confounding factors, such as when prodromal urinary symptoms associated with the early stages of dementia lead to an increase in OAB medication use, rather than the use of OAB medication causing dementia. In patients with potential risk factors for cognitive impairment, the cautious use of selected OAB anticholinergic agents with favourable physicochemical and pharmacokinetic properties and clinical trial evidence of cognitive safety might be appropriate.

The treatment of neurogenic lower urinary tract dysfunction in persons with spinal cord injury: An open label, pilot study of anticholinergic agent vs. mirabegron to evaluate cognitive impact and efficacy

STUDY DESIGN

Pre-post intervention.

OBJECTIVES

1. To test whether replacement of oral anticholinergic (AC) agents with mirabegron for neurogenic lower urinary tract dysfunction (NLUTD) yields improved cognitive function in older persons with spinal cord injury (SCI). 2. To test whether mirabegron is safe and as efficacious as AC.

SETTING

USA.

METHODS

Pilot study: Twenty older (>60 y/o) persons with SCI taking chronic (>6 months) AC medication for NLUTD were enrolled. All participants were first studied on AC at baseline then switched to mirabegron for 6 months. Primary outcomes were cognitive tests of (1) executive function (TEXAS, SDMT); (2) attention (SCWT); and (3) memory (SLUMS and WMS-IV Story A/B). Secondary outcomes assessed efficacy and safety including Neurogenic Bladder Symptom Score (NBSS), bladder diary, neurogenic bowel dysfunction (NBD) survey, heart rate (HR), electrocardiogram (EKG), and mean arterial pressure (MAP).

RESULTS

When switching from AC to mirabegron for NLUTD, older persons with SCI exhibited statistically significant improvements in immediate Story A recall (p = 0.01), delayed story A and B recall (p = 0.01, 0.004), and in TEXAS (p = 0.04). Three subscores within NBSS significantly improved (p = 0.001) and the frequency of incontinence decreased (p = 0.03) on mirabegron. NBD, HR, MAP, and EKGs were unchanged.

CONCLUSIONS

Older persons with SCI on AC for NLUTD demonstrated improved short-term and delayed memory (WMS-IV Story A/B) as well as executive function (TEXAS) when switched to mirabegron. Efficacy of mirabegron for NLUTD symptoms was superior to AC with no adverse effects on bowel or cardiovascular function.

SPONSORSHIP

Claude D. Pepper Older Americans Independence Center.

Comparative risk of adverse outcomes associated with nonselective and selective antimuscarinic medications in older adults with dementia and overactive bladder

OBJECTIVE

The differential muscarinic receptor selectivity could cause selective antimuscarinics to offer advantages over nonselective agents with respect to adverse effects. The objective was to examine the comparative risk of falls/fractures and all-cause hospitalizations among older adults with dementia and overactive bladder (OAB) using nonselective and selective antimuscarinics METHODS/DESIGN: A retrospective cohort study design was conducted among older patients with dementia and OAB using incident antimuscarinics. The primary exposure was classified as nonselective (oxybutynin, tolterodine, trospium, and fesoterodine) and selective (solifenacin and darifenacin). Cox proportional-hazards regression using inverse probability of treatment weighting (IPTW) evaluated the risk of falls/fractures and all-cause hospitalizations within 6 months of nonselective and selective antimuscarinic use.

RESULTS

The study cohort consisted of 13,896 (76.9%) nonselective and 4,179 (23.1%) selective antimuscarinic incident users. The unadjusted falls/fractures rate was 27.14% (3,772) for nonselective and 24.55% (1,026) for selective users (p-value< 0.01). The unadjusted all-cause hospitalizations rate was 24.14% (3,354) for nonselective and 21.58% (902) for selective users (p-value <0.01). The IPTW models did not find a significant difference in the risk of falls/fractures (Hazard Ratio [HR] 1.03; 95% Confidence Interval [CI] 0.99-1.07) and risk of all-cause hospitalizations (HR 1.04; 95% CI 0.99-1.08) between nonselective and selective antimuscarinics. Several sensitivity analyses corroborated the main findings.

CONCLUSIONS

The study did not find a differential risk of falls/fractures and all-cause hospitalizations in older adults with dementia and OAB using nonselective and selective antimuscarinics. More research is needed to understand the role of pharmacodynamics and pharmacokinetics in the safety profile of antimuscarinics in dementia.

Anticholinergic drugs and risk of dementia: Time for action?

Evidence suggests that the prescription of bladder anticholinergics is increasing. Recent studies have accentuated concerns about whether certain prescribed medications could increase risk of dementia, including anticholinergic drugs, and specifically anticholinergics used for bladder symptoms. Nevertheless, it can be difficult to draw together the evidence to review the case for possible causation. Recognising this issue in 1965, Bradford-Hill set out nine criteria to help assess whether evidence of a causal relationship could be inferred between a presumed cause and an observed effect. In this commentary, we explore the extent to which associations between anticholinergics and dementia satisfy the Bradford-Hill criteria and examine the potential implications. First, we look at studies that have examined the relationship between anticholinergic drugs with urological properties (bladder drugs) and the onset of dementia, and then present those studies which specifically focus on the cognitive effects of bladder drugs that affect muscarinic receptors in the brain versus the bladder on older people along with suggestions for future research. We also discuss the risks and benefits of these drugs for treating overactive bladder. If it can be shown that certain medications carry a specific risk of dementia, it is possible that initiatives to change prescribing could become a key tool in reducing the risk of dementia and may be easier to implement than some lifestyle changes.

Neuropathological Correlates of Cumulative Benzodiazepine and Anticholinergic Drug Use

BACKGROUND

Benzodiazepines and anticholinergic drugs have been implicated in causing cognitive decline and potentially increasing dementia risk. However, evidence for an association with neuropathology is limited.

OBJECTIVE

To estimate the correlation between neuropathology at death and prior use of benzodiazepines and anticholinergic drugs.

METHODS

We categorized 298 brain donors from the population-based Medical Research Council Cognitive Function and Ageing Study, according to their history of benzodiazepine (including Z-drugs) or anticholinergic medication (drugs scoring 3 on the Anticholinergic Cognitive Burden scale) use. We used logistic regression to compare dichotomized neuropathological features for those with and without history of benzodiazepine and anticholinergic drug use before dementia, adjusted for confounders.

RESULTS

Forty-nine (16%) and 51 (17%) participants reported benzodiazepine and anticholinergic drug use. Alzheimer's disease neuropathologic change was similar whether or not exposed to either drug, for example 46% and 57% had intermediate/high levels among those with and without anticholinergic drug use. Although not significant after multiple testing adjustments, we estimated an odds ratio (OR) of 0.40 (95% confidence interval [95% CI] 0.18-0.87) for anticholinergic use and cortical atrophy. For benzodiazepine use, we estimated ORs of 4.63 (1.11-19.24) and 3.30 (1.02-10.68) for neuronal loss in the nucleus basalis and substantial nigra. There was evidence of neuronal loss in the nucleus basalis with anticholinergic drug use, but the association reduced when adjusted for confounders.

CONCLUSIONS

We found no evidence that benzodiazepine or anticholinergic drug use is associated with typical pathological features of Alzheimer's disease; however, we cannot rule out effects owing to small numbers.

Mild polypharmacy and MCI progression in older adults: the mediation effect of drug-drug interactions

BACKGROUND

Polypharmacy has been associated with worse cognitive performance, but its impact on mild cognitive impairment (MCI) progression to dementia has not been explored.

AIMS

The aims of the study were to investigate the association between multidrug regimens and MCI progression, and the possible mediation of drug-drug interactions and drugs' anticholinergic effect in such association.

METHODS

This work included 342 older adults with MCI, who were involved in an Italian multicenter population-based cohort study. Information on drugs taken was derived from general practitioners' records and data on drug-drug interactions and anticholinergic burden [evaluated through the Anticholinergic Cognitive Burden and the Anticholinergic Risk Scale (ARS)] were extracted. Multinomial logistic regressions assessed the associations between mild polypharmacy (≥ 3 drugs/day), drug-drug interactions, and anticholinergic burden with MCI changes after 1-year follow-up. Mediation analysis evaluated potential mediators of that relationship.

RESULTS

Approximately, 50% of participants took ≥ 3 drugs/day. During the follow-up, 4.1% of MCI patients progressed to dementia. The odds of developing dementia was sixfold higher in those who took ≥ 3drugs/day (OR = 6.04, 95% CI 1.19-30.74), eightfold higher in those with ≥ 1 drug-drug interaction/s (OR = 8.45, 95% CI 1.70-41.91), and fivefold higher in those with ARS ≥ 1 (OR = 5.10, 95% CI 1.04-24.93). Drug-drug interactions mediated 70.4% of the association between medication number and MCI progression to dementia (p = 0.07).

DISCUSSION

Our study suggests that even mild polypharmacy may increase the risk of MCI progression to dementia, probably due to the presence of drug-drug interactions, which often occur in multidrug regimens.

CONCLUSIONS

Older people require careful management of pharmacological treatments, with special attention to drug-drug interactions and drug-related anticholinergic effects.

Is Combining an Anticholinergic with a Cholinesterase Inhibitor a Good Strategy for High-Level CNS Cholinesterase Inhibition?

The currently approved cholinesterase inhibitors (donepezil, rivastigmine, and galantamine) produce gastrointestinal toxicity which limits dosing to that which produces only about 25% to 35% CNS cholinesterase inhibition in Alzheimer's disease patients undergoing treatment, below the minimum therapeutic target of about 40% to 50% CNS inhibition considered necessary to treat cognitive impairment. A recent strategy for producing high-level CNS acetylcholinesterase (AChE) inhibition (50% or higher) is to co-administer a muscarinic anticholinergic with the AChE inhibitor to block the dose-limiting cholinergic overstimulation of the gastrointestinal system, allow more robust AChE inhibition in the CNS, and improve efficacy in the treatment of Alzheimer's disease. Unfortunately, most common muscarinic anticholinergics, including solifenacin, readily penetrate the CNS and are directly associated with long-term exacerbation of the underlying neuropathology of Alzheimer's disease and increased brain atrophy. The co-administration of an anticholinergic with an AChE inhibitor is a rational strategy for improving efficacy in the symptomatic treatment of dementia, but there are significant long-term risks that have not yet been considered. For long-term safety against accelerating the underlying disease processes in Alzheimer's disease, anticholinergics used to increase the tolerability of AChE inhibitors should not penetrate, or have very limited penetration, of the blood-brain barrier. Neurotrophic-mediated mechanisms by which cholinergic drugs may affect neurodegeneration in Alzheimer's disease are explored and improved treatment options are suggested.

Increased risk of incident dementia following use of anticholinergic agents: A systematic literature review and meta-analysis

Background/rationale

Long‐term treatment with anticholinergic agents may increase the risk of cognitive impairment or dementia. This systematic literature review and meta‐analysis aimed to assess the impact of ≥3 months of exposure to anticholinergics as a class on the risk of dementia, mild cognitive impairment, and change in cognitive function. The impact of anticholinergic agents specifically used to treat overactive bladder was also evaluated.

Materials and Methods

A systematic literature review was conducted to identify English language articles evaluating the impact of anticholinergic use for ≥3 months on dementia or cognitive function in adult patients. Databases searched included PubMed, Embase, and the Cochrane Library. Meta‐analyses were conducted using random‐effects models; 95% confidence intervals (CIs) and 95% prediction intervals (PIs) were reported.

Results

A total of 2122 records were identified. Out of those, 21 studies underwent qualitative synthesis and 6 reported endpoints relevant for inclusion in a meta‐analysis assessing the risk of incident dementia. The overall rate ratio for incident dementia was 1.46 (95% CI: 1.17–1.81; 95% PI: 0.70–3.04; n = 6). The risk of incident dementia increased with increasing exposure (n = 3). In addition, two studies from the meta‐analysis reported an increased risk of dementia with ≥3 months of use of bladder antimuscarinics (adjusted odds ratios ranged from 1.21 to 1.65, depending on exposure category).

Conclusion

Anticholinergic use for ≥3 months increased the risk of dementia on average by an estimated 46% versus nonuse. This relationship was consistent in studies assessing overactive bladder medications. The risk of developing dementia should be carefully considered in the context of potential benefit before prescribing anticholinergics.

Quetiapine and novel PDE10A inhibitors potentiate the anti-BuChE activity of donepezil

The symptoms of Alzheimer’s disease (AD) do not include only memory loss and cognitive decline but also neuropsychiatric manifestation. These AD-related symptoms are usually treated with the aid of antipsychotics; however, their effects on cognition and safety remain unexplored. The present study determines the effects of quetiapine, an atypical antipsychotic, and two imidazo[1,2-a]pyrimidine-based inhibitors of PDE10A on the activity of human cholinesterases. Quetiapine moderately inhibited BuChE (IC₅₀ = 6.08 ± 1.64 µmol/L) but improved the anti-BuChE properties of donepezil by decreasing its IC₅₀ value. Both PDE10A inhibitors were found to possess moderate anti-AChE properties. The combined mixtures of donepezil and imidazo[1,2-a]pyrimidine analogues produce a synergistic anti-BuChE effect which was greater than either compound alone, improving the IC₅₀ value by approximately six times. These favourable interactions between quetiapine, PDE10A inhibitors and clinically approved donepezil, resulting in improved anti-BuChE activity, can lead to a wider variety of potent AD treatment options.

Anticholinergic medications and risk of dementia in older adults: Where are we now?

INTRODUCTION

Anticholinergic medications are effective for a wide variety of indications, but are associated with significant central adverse effects, especially cognitive decline and dementia in older adults.

AREAS COVERED

We conducted a review of relevant literature in the past decade to address anticholinergic scales and evidence of anticholinergic-related dementia/cognitive decline in older adults. We discussed various anticholinergic scales used to classify anticholinergic medications. The review focused on the evidence from previous reviews and individual studies evaluating the anticholinergic-related risk of developing cognitive decline/dementia. This review also discussed clinical and methodological issues of studies along with recommendations for practice and research.

EXPERT OPINION

The review demonstrates moderate to strong risk of dementia with anticholinergic use in multiple studies involving older adults, irrespective of the study design, analytical approach, anticholinergic exposure and outcome definition. This risk is particularly significant with the cumulative burden and high-level anticholinergics. There also exists a dose-response relationship between anticholinergic use and increased risk for dementia. Therefore, anticholinergic agents can be considered as a modifiable risk factor for dementia and cognitive decline in older adults. Based on the current evidence, regular assessment and optimization of anticholinergic burden prior to prescribing these medications can minimize anticholinergic-related morbidity in older adults.

Anticholinergics May Carry Significant Cognitive and Gait Burden in Parkinson's Disease

Background

Anticholinergic drugs are associated with significant cognitive and other adverse events in older adults, including those with Parkinson's disease (PD). Anticholinergic effects are considered lesser in younger individuals and the burden and outcomes in younger patients with PD are unknown.

Objectives

To determine the cumulative anticholinergic burden in a cohort of younger of patients with PD and to correlate the same with cognitive impairment and freezing of gait (FOG).

Methods

We conducted a cross-sectional study to identify the cumulative anticholinergic burden from medications prescribed to patients with PD. Two standard scales, the Anticholinergic Cognitive Burden (ACB) scale and the ACB score, were used to calculate the anticholinergic burden from prescriptions. We identified commonly prescribed drugs contributing to anticholinergic effects and correlated the cumulative ACB score with cognitive impairment (Movement Disorder Society-Unified Parkinson's Disease Rating Scale item 1.1) and FOG (Movement Disorder Society-Unified Parkinson's Disease Rating Scale items 2.13 and 3.11).

Results

We recruited 287 patients with PD (68.9% male) with a mean age of 56.9 ± 11.8 years and a duration of symptoms 6.3 ± 6.9 years. Median ACB score was 4 (range 0-12). A total of 164 (58.4%) patients had total ACB score > 3. ACB score > 3 was independently associated with cognitive impairment (Odds Ratio, 2.55; 95% confidence interval, 1.43-4.53; P < 0.001) and FOG using patient-reported measures (Odds Ratio, 3.192; 95% Confidence Interval, 1.68-6.07; P < 0.001) and objective measures (odds ratio, 2.41; 95% confidence interval, 1.27-4.6, P = 0.007).

Conclusion

Patients with PD are exposed to significant anticholinergic burden from drugs prescribed for PD and non-PD indications. Higher anticholinergic burden is associated with cognitive impairment and FOG even in younger patients with PD.

The cognitive safety of antimuscarinics in the treatment of overactive bladder

INTRODUCTION

Overactive bladder is a common problem women suffer from, with its incidence increasing with age. The mainstay of treatment is antimuscarinic medication. There is growing evidence that antimuscarinics may increase the risk of cognitive impairment, dementia, and even death.

AREAS COVERED

This review explores the evidence that antimuscarinics increase the risk of cognitive impairment, dementia, and death. It evaluates how best to treat overactive bladder the older woman.

EXPERT OPINION

The evidence suggests that antimuscarinics increase the risk of cognitive impairment and dementia in the older adult. Care should be taken to use an antimuscarinic that is less likely to cross the blood-brain barrier and thus reduce the risk of these significant adverse events. A patient's anticholinergic load also needs to be considered when treating this group. Other treatment options such as fluid management, bladder retraining, vaginal estrogens, mirabegron, Onabotulinum toxin A and neuromodulation can be used instead.

Cognitive Effects of Anticholinergic Load in Women with Overactive Bladder

Overactive bladder syndrome (OAB) is defined as urinary urgency, usually accompanied by frequency and nocturia, with or without urgency incontinence, in the absence of urinary tract infection or other obvious pathology. The mainstay of treatment of OAB is anticholinergic/antimuscarinic medication. These drugs block muscarinic receptors throughout the body, not only the bladder, including in the brain, which may lead to cognitive side effects. Anticholinergic load or burden is the cumulative effect of taking drugs that are capable of producing anticholinergic adverse effects. The elderly are more susceptible to these effects, especially as there is increased permeability of the blood brain barrier. The anticholinergic drugs for OAB are able to enter the central nervous system and lead to central side effects. There is increasing evidence that a high anticholinergic load is linked to the development of cognitive impairment and even dementia. Some studies have found an increased risk of mortality. In view of this, care is needed when treating OAB in the elderly. Trospium chloride is a quaternary amine anticholinergic, which has a molecular structure, which theoretically means it is less likely to cross the blood brain barrier and exert central side effects. Alternatively, mirabegron can be used, which is a beta-3 adrenoceptor agonist, which does not add to the anticholinergic load or exert central nervous system side effects. Conservative therapy can be used as an alternative to pharmacological treatment in the form of behavioral modification, fluid management and bladder retraining. Neuromodulation or the use of botox can also be alternatives, but success may be less in the older adult and will require increased hospital attendances.

Muscarinic acetylcholine receptor regulates self-renewal of early erythroid progenitors

Adult stem and progenitor cells are uniquely capable of self-renewal, and targeting this process represents a potential therapeutic opportunity. The early erythroid progenitor, burst-forming unit erythroid (BFU-E), has substantial self-renewal potential and serves as a key cell type for the treatment of anemias. However, our understanding of mechanisms underlying BFU-E self-renewal is extremely limited. Here, we found that the muscarinic acetylcholine receptor, cholinergic receptor, muscarinic 4 (CHRM4), pathway regulates BFU-E self-renewal and that pharmacological inhibition of CHRM4 corrects anemias of myelodysplastic syndrome (MDS), aging, and hemolysis. Genetic down-regulation of CHRM4 or pharmacologic inhibition of CHRM4 using the selective antagonist PD102807 promoted BFU-E self-renewal, whereas deletion of Chrm4 increased erythroid cell production under stress conditions in vivo. Moreover, muscarinic acetylcholine receptor antagonists corrected anemias in mouse models of MDS, aging, and hemolysis in vivo, extending the survival of mice with MDS relative to that of controls. The effects of muscarinic receptor antagonism on promoting expansion of BFU-Es were mediated by cyclic AMP induction of the transcription factor CREB, whose targets up-regulated key regulators of BFU-E self-renewal. On the basis of these data, we propose a model of hematopoietic progenitor self-renewal through a cholinergic-mediated "hematopoietic reflex" and identify muscarinic acetylcholine receptor antagonists as potential therapies for anemias associated with MDS, aging, and hemolysis.

Improving Anti-Neurodegenerative Benefits of Acetylcholinesterase Inhibitors in Alzheimer's Disease: Are Irreversible Inhibitors the Future?

Decades of research have produced no effective method to prevent, delay the onset, or slow the progression of Alzheimer's disease (AD). In contrast to these failures, acetylcholinesterase (AChE, EC 3.1.1.7) inhibitors slow the clinical progression of the disease and randomized, placebo-controlled trials in prodromal and mild to moderate AD patients have shown AChE inhibitor anti-neurodegenerative benefits in the cortex, hippocampus, and basal forebrain. CNS neurodegeneration and atrophy are now recognized as biomarkers of AD according to the National Institute on Aging-Alzheimer's Association (NIA-AA) criteria and recent evidence shows that these markers are among the earliest signs of prodromal AD, before the appearance of amyloid. The current AChE inhibitors (donepezil, rivastigmine, and galantamine) have short-acting mechanisms of action that result in dose-limiting toxicity and inadequate efficacy. Irreversible AChE inhibitors, with a long-acting mechanism of action, are inherently CNS selective and can more than double CNS AChE inhibition possible with short-acting inhibitors. Irreversible AChE inhibitors open the door to high-level CNS AChE inhibition and improved anti-neurodegenerative benefits that may be an important part of future treatments to more effectively prevent, delay the onset, or slow the progression of AD.

Cumulative use of therapeutic bladder anticholinergics and the risk of dementia in patients with lower urinary tract symptoms: a nationwide 12-year cohort study

Background

Studies have shown an association between lower urinary tract symptoms (LUTS) and an increased risk of dementia. Whether anticholinergic use contributes to the development of dementia in patients with LUTS remains unknown, especially in Asian populations. This study aims to investigate the association between anticholinergic use and dementia in patients with LUTS.

Methods

This study included patients aged 50 years and over with newly diagnosed LUTS (January 2001 to December 2005), divided into four groups according to their cumulative defined daily doses (cDDDs) of anticholinergics: < 28 cDDDs, 28–84 cDDDs, 85–336 cDDDs, ≥337 cDDDs. Patients were followed up until dementia developed or until the end of 2012.

Results

We recruited a total of 16,412 patients. The incidence of dementia was 10% in the < 28 cDDD group, 8.9% in the 28–84 cDDD group, 11.5% in the 85–336 cDDD group, and 14.4% in the ≥337 cDDD group (p = .005). In a Cox proportional hazards analysis, the adjusted hazard ratio of dementia was 1.15 (95% CI = 0.97–1.37) in the 85–336 cDDD group, and 1.40 (95% CI = 1.12–1.75) in the ≥337 cDDD group after adjusting for covariates.

Conclusions

Our study indicates that higher cumulative anticholinergic exposure is associated with an increase in the risk of incident dementia in patients with LUTS aged 50 years of age and over. Either using one anticholinergic agent or switching anticholinergic agents cumulatively increases this risk. Therapeutic risks and benefits of using anticholinergics in LUTS treatment should be clinically reviewed and weighed.

Anticholinergic Drugs in Geriatric Psychopharmacology

Drugs with anticholinergic action are widely prescribed in the elderly population due to their potential clinical benefits. However, these benefits are limited by adverse effects which may be serious in particular circumstances. This review presents different aspects of the use of anticholinergics in old age with a focus in psychogeriatric patients. We critically review published data on benefits and disadvantages of anticholinergics, which are often controversial. Prevalence, pathophysiology and measurement methods of the anticholinergic action of drugs are discussed. We also present the most important drawbacks resulting from its use, including effects on cognition in healthy and cognitively impaired people, in aged schizophrenia patients, emergence of delirium and psychiatric symptoms, influence in functionality, hospitalization, institutionalization and mortality, and the potential benefits and limitations of their discontinuation. Finally, we suggest practical recommendations for the safe use of anticholinergics in clinical conditions affecting elderly patients, such as dementia, schizophrenia and acute hallucinatory episodes, depression, anxiety, Parkinson's disease, cardiovascular conditions and urinary incontinence.

The burden of sialorrhoea in chronic neurological conditions: current treatment options and the role of incobotulinumtoxinA (Xeomin®)

Sialorrhoea is a frequent symptom of neurological diseases (e.g. Parkinson’s disease, motor neuron disease, cerebral palsy, and stroke) and is defined as excessive saliva accumulation leading to unintentional loss of saliva from the mouth. Sialorrhoea increases the overall burden on the patient and their caregivers, the impact of which can be both physical and psychosocial. Treatments for sialorrhoea range from lifestyle and behavioural guidance, to medications, surgery or radiation. Nonpharmacological interventions include advice on posture, swallowing control, cough management, dietary changes, eating and drinking techniques, and behavioural modification; however, these conservative measures may be ineffective for people with progressive neurological conditions. The pharmacological treatment of sialorrhoea is challenging because medications licensed for this purpose are limited, but treatments can include anticholinergic drugs and botulinum toxins. Surgical treatment of sialorrhoea is typically reserved as a last resort for patients. IncobotulinumtoxinA (Xeomin®) is the first botulinum toxin type A to receive US and UK marketing authorization for the symptomatic treatment of chronic sialorrhoea due to neurological disorders in adults. In this review, we discuss and compare the frequency and method of administration, location of treatment delivery, approximate annual costs and main side effects of botulinum toxin and different anticholinergic drugs. Management of patients with chronic neurological conditions requires input from multiple specialist teams and thus a multidisciplinary team (MDT) approach is considered fundamental to ensure that care is consistent and tailored to patients’ needs. To ensure that adult patients with neurological conditions receive the best care and sialorrhoea is well managed, we suggest a potential clinical care pathway for sialorrhoea with a MDT approach, which healthcare professionals could aspire to.

Anticholinergic and benzodiazepine medication use and risk of incident dementia: a UK cohort study

Background

Studies suggest that anticholinergic medication or benzodiazepine use could increase dementia risk. We tested this hypothesis using data from a UK cohort study.

Methods

We used data from the baseline (Y0), 2-year (Y2) and 10-year (Y10) waves of the Medical Research Council Cognitive Function and Ageing Study. Participants without dementia at Y2 were included (n = 8216). Use of benzodiazepines (including nonbenzodiazepine Z-drugs), anticholinergics with score 3 (ACB3) and anticholinergics with score 1 or 2 (ACB12) according to the Anticholinergic Cognitive Burden scale were coded as ever use (use at Y0 or Y2), recurrent use (Y0 and Y2), new use (Y2, but not Y0) or discontinued use (Y0, but not Y2). The outcome was incident dementia by Y10. Incidence rate ratios (IRR) were estimated using Poisson regression adjusted for potential confounders. Pre-planned subgroup analyses were conducted by age, sex and Y2 Mini-Mental State Examination (MMSE) score.

Results

Dementia incidence was 9.3% (N = 220 cases) between Y2 and Y10. The adjusted IRRs (95%CI) of developing dementia were 1.06 (0.72, 1.60), 1.28 (0.82, 2.00) and 0.89 (0.68, 1.17) for benzodiazepines, ACB3 and ACB12 ever-users compared with non-users. For recurrent users the respective IRRs were 1.30 (0.79, 2.14), 1.68 (1.00, 2.82) and 0.95 (0.71, 1.28). ACB3 ever-use was associated with dementia among those with Y2 MMSE> 25 (IRR = 2.28 [1.32–3.92]), but not if Y2 MMSE≤25 (IRR = 0.94 [0.51–1.73]).

Conclusions

Neither benzodiazepines nor ACB12 medications were associated with dementia. Recurrent use of ACB3 anticholinergics was associated with dementia, particularly in those with good baseline cognitive function. The long-term prescribing of anticholinergics should be avoided in older people.

Exposure to Strong Anticholinergic Medications and Dementia-Related Neuropathology in a Community-Based Autopsy Cohort

BACKGROUND

Anticholinergic medication exposure has been associated with increased risk for dementia. No study has examined the association between anticholinergic medication use and neuropathologic lesions in a community-based sample.

OBJECTIVE

To examine the relationship between anticholinergic exposure and dementia-related neuropathologic changes.

METHODS

Within a community-based autopsy cohort (N = 420), we ascertained use of anticholinergic medications over a 10-year period from automated pharmacy data and calculated total standardized daily doses (TSDD). We used modified Poisson regression to calculate adjusted relative risks (RRs) and 95% confidence intervals (CIs) for the association between anticholinergic exposure and dementia-associated neuropathology. Inverse probability weighting was used to account for selection into the autopsy cohort.

RESULTS

Heavy anticholinergic exposure (≥1,096 TSDD) was not associated with greater neuropathologic changes of Alzheimer's disease; the adjusted RRs for heavy use of anticholinergics (≥1,096 TSDD) compared to no use were 1.22 (95% CI 0.81-1.88) for neuritic plaque scores and 0.89 (0.47-1.66) for extent of neurofibrillary degeneration. Moderate (91-1,095 TSDD) and heavy use of anticholinergics was associated with a significantly lower cerebral microinfarct burden compared with no use with adjusted RRs of 0.44 (0.21-0.89) and 0.24 (0.09-0.62), respectively. Anticholinergic exposure was not associated with macroscopic infarcts or atherosclerosis.

CONCLUSIONS

Use of anticholinergic medications is not associated with Alzheimer's disease-related neuropathologic changes but is associated with lower cerebral microinfarct burden. Further research into biological mechanisms underlying the anticholinergic-dementia link is warranteds.

Association between Anticholinergic Medication Use and Risk of Dementia among Patients with Parkinson's Disease

STUDY OBJECTIVES

To evaluate the association between anticholinergic medication use, categorized by anticholinergic cognitive burden (primary objective) and cumulative dose (secondary objective), and the risk of developing dementia among patients with Parkinson's disease.

DESIGN

Retrospective cohort study with an active comparator design.

DATA SOURCE

National Health Insurance Research Database in Taiwan (2001-2011).

PATIENTS

A total of 1232 adults with Parkinson's disease who were diagnosed between 2002 and 2004 and taking at least one antiparkinson medication during this period were included. Of these patients, 694 were exposed to anticholinergic medications categorized as mild (reference group), and 538 were exposed to anticholinergic medications categorized as moderate or severe (exposure group).

MEASUREMENTS AND MAIN RESULTS

Exposure to different types of anticholinergic medications was categorized by using the Anticholinergic Cognitive Burden (ACB) scale, and cumulative doses of anticholinergic medications were measured by using the cumulative minimum doses (cMD) method. Associations between anticholinergic medication use and risk of dementia were assessed by multivariable Cox proportional hazards models. The type of anticholinergics used (moderate or severe vs mild ACB) was not significantly associated with an increased risk of developing dementia (hazard ratio [HR] 0.97, 95% confidence interval [CI] 0.72-1.27). After adjusting for confounders, a high cumulative dose of anticholinergic drug (> 1095 cumulative minimum doses [cMDs]) was found to be significantly associated with an increased risk of developing dementia when compared with a low cumulative dose of anticholinergic drug (≤ 90 cMDs) (HR 3.06, 95% CI 1.35-6.97).

CONCLUSION

Among patients with Parkinson's disease in Taiwan, those with a high cumulative dose of anticholinergics had an increased risk of being diagnosed with dementia. Physicians should consider prescribing the lowest therapeutic dose of anticholinergic medication when making treatment decisions for patients with Parkinson's disease.

Antimuscarinic drug therapy for overactive bladder syndrome in the elderly - are the concerns justified?

INTRODUCTION

The use of antimuscarinic drugs is common in the management of the overactive bladder (OAB). Concerns have been raised over their use in the elderly population in whom the use of these drugs is highly prevalent, consequent to the reported link between these drugs and cognitive impairment and dementia. Areas covered: Recent publications have heightened concerns regarding antimuscarinic drug use in the elderly. In this review, the author discusses the available evidence upon which conclusions have been based and has presented the need for cortical review and need for caution in interpreting the data. The available evidence is inconsistent, differences in pharmacokinetics have not been widely recognized in clinical trials, clinical estimation of antimuscarinic activity has not been standardized, and serum antimuscarinic activity has not been found to correlate with cognitive impairment. Furthermore, the significant heterogeneity within cognitive aging processes raises questions regarding the extent to which various factors, including medication, influences this process. Expert opinion: Whilst caution should indeed be exercised in the use of antimuscarinic medication in the elderly, advocacy of discontinuation of their use may deprive patients of the benefits of improved quality of life from treatment where currently alternative management remain limited or invasive.

Muscarinic Receptor M3R Signaling Prevents Efficient Remyelination by Human and Mouse Oligodendrocyte Progenitor Cells

Muscarinic receptor antagonists act as potent inducers of oligodendrocyte differentiation and accelerate remyelination. However, the use of muscarinic antagonists in the clinic is limited by poor understanding of the operant receptor subtype, and questions regarding possible species differences between rodents and humans. Based on high selective expression in human oligodendrocyte progenitor cells (OPCs), we hypothesized that M₃R is the functionally relevant receptor. Lentiviral M₃R knockdown in human primary CD140a/PDGFαR⁺ OPCs resulted in enhanced differentiation in vitro and substantially reduced the calcium response following muscarinic agonist treatment. Importantly, following transplantation in hypomyelinating shiverer/rag2 mice, M₃R knockdown improved remyelination by human OPCs. Furthermore, conditional M₃R ablation in adult NG2-expressing OPCs increased oligodendrocyte differentiation and led to improved spontaneous remyelination in mice. Together, we demonstrate that M₃R receptor mediates muscarinic signaling in human OPCs that act to delay differentiation and remyelination, suggesting that M₃ receptors are viable targets for human demyelinating disease.SIGNIFICANCE STATEMENT The identification of drug targets aimed at improving remyelination in patients with demyelination disease is a key step in development of effective regenerative therapies to treat diseases, such as multiple sclerosis. Muscarinic receptor antagonists have been identified as effective potentiators of remyelination, but the receptor subtypes that mediate these receptors are unclear. In this study, we show that genetic M₃R ablation in both mouse and human cells results in improved remyelination and is mediated by acceleration of oligodendrocyte commitment from oligodendrocyte progenitor cells. Therefore, M₃R represents an attractive target for induced remyelination in human disease.

Anticholinergics Influence Transition from Normal Cognition to Mild Cognitive Impairment in Older Adults in Primary Care

STUDY OBJECTIVE

To determine the influence of anticholinergic medications on transitions in cognitive diagnosis of older adults in primary care.

DESIGN

This observational cohort study was conducted over a mean follow-up of 3.2 years. Anticholinergic exposure was defined by pharmacy dispensing and claims records. Cognitive diagnosis was performed by an expert panel at baseline and annually up to 4 years.

DATA SOURCE

Medication exposure and other clinical data were extracted from the Indiana Network for Patient Care (INPC). The cognitive diagnosis was derived from a cognitive screening and diagnosis study.

PARTICIPANTS

A total of 350 adults 65 years and older without dementia and receiving primary care in a safety net health care system.

MEASUREMENT AND MAIN RESULTS

Cognitive diagnosis followed a two-phase screening and consensus-based neuropsychiatric examination to determine a baseline diagnosis as normal cognition, mild cognitive impairment (MCI), or dementia, with a follow-up neuropsychiatric examination and consensus-based diagnosis repeated annually. The Anticholinergic Cognitive Burden scale was used to identify anticholinergics dispensed up to 10 years before enrollment and annually throughout the study. A total standard daily dose of anticholinergics was calculated by using pharmacy dispensing data from the INPC. Among 350 participants, a total of 978 diagnostic assessments were completed over a mean follow-up of 3.2 years. Compared with stable cognition, increasing use of strong anticholinergics calculated by total standard daily dose increased the odds of transition from normal cognition to MCI (odds ratio [OR] 1.15, 95% confidence interval [CI] 1.01-1.31, p = 0.0342). Compared with stable MCI, strong anticholinergics did not influence the reversion of MCI to normal cognition (OR 0.95, 95% CI 0.86-1.05, p = 0.3266).

CONCLUSION

De-prescribing interventions in older adults with normal cognition should test anticholinergics as potentially modifiable risk factors for cognitive impairment.

Anticholinergic drugs and risk of dementia: case-control study

OBJECTIVES

To estimate the association between the duration and level of exposure to different classes of anticholinergic drugs and subsequent incident dementia.

DESIGN

Case-control study.

SETTING

General practices in the UK contributing to the Clinical Practice Research Datalink.

PARTICIPANTS

40 770 patients aged 65-99 with a diagnosis of dementia between April 2006 and July 2015, and 283 933 controls without dementia.

INTERVENTIONS

Daily defined doses of anticholinergic drugs coded using the Anticholinergic Cognitive Burden (ACB) scale, in total and grouped by subclass, prescribed 4-20 years before a diagnosis of dementia.

MAIN OUTCOME MEASURES

Odds ratios for incident dementia, adjusted for a range of demographic and health related covariates.

RESULTS

14 453 (35%) cases and 86 403 (30%) controls were prescribed at least one anticholinergic drug with an ACB score of 3 (definite anticholinergic activity) during the exposure period. The adjusted odds ratio for any anticholinergic drug with an ACB score of 3 was 1.11 (95% confidence interval 1.08 to 1.14). Dementia was associated with an increasing average ACB score. When considered by drug class, gastrointestinal drugs with an ACB score of 3 were not distinctively linked to dementia. The risk of dementia increased with greater exposure for antidepressant, urological, and antiparkinson drugs with an ACB score of 3. This result was also observed for exposure 15-20 years before a diagnosis.

CONCLUSIONS

A robust association between some classes of anticholinergic drugs and future dementia incidence was observed. This could be caused by a class specific effect, or by drugs being used for very early symptoms of dementia. Future research should examine anticholinergic drug classes as opposed to anticholinergic effects intrinsically or summing scales for anticholinergic exposure.

TRIAL REGISTRATION

Registered to the European Union electronic Register of Post-Authorisation Studies EUPAS8705.

Plants-Derived Neuroprotective Agents: Cutting the Cycle of Cell Death through Multiple Mechanisms

Neuroprotection is the preservation of the structure and function of neurons from insults arising from cellular injuries induced by a variety of agents or neurodegenerative diseases (NDs). The various NDs including Alzheimer's, Parkinson's, and Huntington's diseases as well as amyotropic lateral sclerosis affect millions of people around the world with the main risk factor being advancing age. Each of these diseases affects specific neurons and/or regions in the brain and involves characteristic pathological and molecular features. Hence, several in vitro and in vivo study models specific to each disease have been employed to study NDs with the aim of understanding their underlying mechanisms and identifying new therapeutic strategies. Of the most prevalent drug development efforts employed in the past few decades, mechanisms implicated in the accumulation of protein-based deposits, oxidative stress, neuroinflammation, and certain neurotransmitter deficits such as acetylcholine and dopamine have been scrutinized in great detail. In this review, we presented classical examples of plant-derived neuroprotective agents by highlighting their structural class and specific mechanisms of action. Many of these natural products that have shown therapeutic efficacies appear to be working through the above-mentioned key multiple mechanisms of action.

Midlife anticholinergic drug use, risk of Alzheimer's disease, and brain atrophy in community-dwelling older adults

Introduction

We examined how long-term anticholinergic (AC) drug use beginning at midlife affects risk of Alzheimer's disease (AD) and rates of brain atrophy in cognitively normal older adults.

Methods

We followed 723 individuals (mean baseline age 52.3 years; mean follow-up interval 20.1 years) in the Baltimore Longitudinal Study of Aging. The AC drug exposure was defined using the Anticholinergic Cognitive Burden Scale: Nonusers (n = 404), as well as participants exposed to medications with AC activity but without known clinically relevant negative cognitive effects (i.e., “possible AC users”; n = 185) and those exposed to AC drugs with established and clinically relevant negative cognitive effects (i.e., “definite AC users”; n = 134). The neuroimaging sample included 93 participants who remained cognitively normal through follow-up and underwent serial magnetic resonance imaging (n = 93, 724 brain scans, mean follow-up interval 8.2 years, and baseline age 68.6 years).

Results

Possible AC users, but not definite AC users, showed increased risk of incident AD compared with nonusers (hazard ratio, 1.63; 95% confidence interval, 1.02–2.61; P = .04) and greater rates of atrophy in total cortical gray matter volume compared with nonusers (β = −0.74, P = .018). Faster rates of brain atrophy were also observed among possible AC users in the right posterior cingulate, as well as right middle frontal and left superior temporal gyri. Data on frequency and duration of medication use were available in only approximately half of the sample. Among these participants, definite AC users had both shorter duration and lower frequency of medication use relative to possible AC users.

Discussion

Long-term exposure to medications with mild AC activity during midlife is associated with increased risk of AD and accelerated brain atrophy.

Imaging the Nonmotor Symptoms in Parkinson's Disease

Parkinson's disease is acknowledged to be a multisystem syndrome, manifesting as a result of multineuropeptide dysfunction, including dopaminergic, cholinergic, serotonergic, and noradrenergic deficits. This multisystem disorder ultimately leads to the presentation of a range of nonmotor symptoms, now appreciated to be an integral part of the disease-specific spectrum of symptoms, often preceding the diagnosis of motor Parkinson's disease. In this chapter, we review the dopaminergic and nondopaminergic basis of these symptoms by exploring the neuroimaging evidence based on several techniques including positron emission tomography, single-photon emission computed tomography molecular imaging, magnetic resonance imaging, functional magnetic resonance imaging, and diffusion tensor imaging. We discuss the role of these neuroimaging techniques in elucidating the underlying pathophysiology of NMS in Parkinson's disease.

Anticholinergic prescription: are healthcare professionals the real burden?

INTRODUCTION AND HYPOTHESIS

Anticholinergic medication is the medical treatment for overactive bladder (OAB). These drugs can act on the central nervous system and can lead to cognitive decline, dementia, and potentially death. Patients taking drugs with anticholinergic effects increase their anticholinergic burden-defined as the cumulative effect of taking one or more drugs that can have adverse effects. When prescribing anticholinergic medication for the elderly, we must choose the right drug. We aimed to discover the level of understanding on this subject and its application to real clinical practice amongst our healthcare professionals (HCPs).

METHODS

An 18-point questionnaire was distributed to urogynaecologists, general gynaecologists, urologists, geriatricians, general practitioners (GPs), and nurse specialists to assess knowledge on the subject.

RESULTS

A total of 96 HCPs completed the questionnaire. The nurse specialists had the highest score in identifying that oxybutynin was the drug most likely to cross the blood-brain barrier (BBB). The urogynaecologists had the highest score in identifying that trospium chloride was least likely to cross the BBB, whereas the GPs had the lowest score. Solifenacin was the most popular anticholinergic drug prescribed in the elderly without dementia. Trospium chloride was the most popular drug prescribed in the elderly with dementia.

CONCLUSIONS

We have found that knowledge is lacking amongst all our HCPs, but especially amongst our first-line doctors, our GPs. Education is key in developing knowledge and safe prescribing, to improve the care we give to our patients.

Anticholinergic Load: Is there a Cognitive Cost in Early Parkinson's Disease?

We evaluated the effect of anticholinergic burden on 219 participants with incident Parkinson's disease (PD) and 99 controls at study baseline and 18 months. Anticholinergic burden for each individual was calculated and summed according to the Anticholinergic Drug Scale (ADS). Medication with anticholinergic activity was more commonly prescribed in PD compared to controls, although mean ADS scores were not significantly different. Cognitive scores did not differ in PD participants taking medications with anticholinergic activity compared to those who were not. Low overall ADS scores due to increased awareness of adverse effects of medications and brevity of follow-up are potential explanations.

Mini Review: Anticholinergic Activity as a Behavioral Pathology of Lewy Body Disease and Proposal of the Concept of "Anticholinergic Spectrum Disorders"

Given the relationship between anticholinergic activity (AA) and Alzheimer's disease (AD), we rereview our hypothesis of the endogenous appearance of AA in AD. Briefly, because acetylcholine (ACh) regulates not only cognitive function but also the inflammatory system, when ACh downregulation reaches a critical level, inflammation increases, triggering the appearance of cytokines with AA. Moreover, based on a case report of a patient with mild AD and slightly deteriorated ACh, we also speculate that AA can appear endogenously in Lewy body disease due to the dual action of the downregulation of ACh and hyperactivity of the hypothalamic-pituitary-adrenal axis. Based on these hypotheses, we consider AA to be a behavioral pathology of Lewy body disease. We also propose the concept of “anticholinergic spectrum disorders,” which encompass a variety of conditions, including AD, Lewy body disease, and delirium. Finally, we suggest the prescription of cholinesterase inhibitors to patients in this spectrum of disorders to abolish AA by upregulating ACh.

Anticholinergic medication use and dementia: latest evidence and clinical implications

Use of medications with anticholinergic activity is widespread in older adults. Several studies have highlighted that anticholinergic use may be associated with an increased risk of dementia. The objective of this narrative review is to describe and evaluate studies of anticholinergic medication use and dementia and provide practical suggestions for avoiding use of these medications in older adults. A comprehensive review of the literature, citations from recent reviews and the author's personal files was conducted. Four studies were found that evaluated anticholinergic use and dementia as the primary outcome. Three studies focused on overall anticholinergic medication use and reported a statistically significantly increased risk of Alzheimer's disease or dementia. In one study, dementia risk was primarily found with higher cumulative doses; people using anticholinergic medications at the minimum effective dose recommended for older adults for at least 3 years were at highest risk. In contrast, a study conducted in nursing-home residents with depression did not find that paroxetine [a highly anticholinergic selective serotonin reuptake inhibitor antidepressant, (SSRI)] increased risk for dementia compared with other SSRIs (without anticholinergic activity). Further study is needed to understand the mechanism by which anticholinergic medications may increase risk. In conclusion, there is evidence from three observational studies suggesting that anticholinergic medications may increase dementia risk. Given this potential risk and the myriad of other well-known adverse effects (i.e. constipation, blurred vision, urinary retention, and delirium) associated with anticholinergic medications, it is prudent for prescribers and older adults to minimize use of these medications and consider alternatives when possible.