Drugs with Anticholinergic Properties as a Risk Factor for Psychosis in Patients Affected by Alzheimer’s Disease

Development of the Swedish anticholinergic burden scale (Swe-ABS)

BACKGROUND

Drugs with anticholinergic properties are associated with cognitive adverse effects, especially in patients vulnerable to central muscarinic antagonism. A variety of drugs show weak, moderate or strong anticholinergic effects. Therefore, the cumulative anticholinergic burden should be considered in patients with cognitive impairment. This study aimed to develop a Swedish Anticholinergic Burden Scale (Swe-ABS) to be used in health care and research.

METHODS

A systematic literature review was conducted in PubMed and Ovid Embase to identify previously published tools quantifying anticholinergic drug burden (i.e., exposure). Drugs and grading scores (0-3, no to high anticholinergic activity) were extracted from identified lists. Enteral and parenteral drugs authorized in Sweden were included. Drugs with conflicting scores in the existing lists were assessed by an expert group. Two drugs that were not previously assessed were also added to the evaluation process.

RESULTS

The systematic literature search identified the following nine anticholinergic burden scales: Anticholinergic Activity Scale, Anticholinergic Burden Classification, updated Anticholinergic Cognitive Burden scale, Anticholinergic Drug Scale, Anticholinergic Load Scale, Anticholinergic Risk Scale, updated Clinician-rated Anticholinergic Scale, German Anticholinergic Burden Scale and Korean Anticholinergic Burden Scale. A list of drugs with significant anticholinergic effects provided by The Swedish National Board of Health and Welfare was included in the process. The suggested Swe-ABS consists of 104 drugs scored as having weak, moderate or strong anticholinergic effects. Two hundred and fifty-six drugs were listed as having no anticholinergic effects based on evaluation in previous scales. In total, 62 drugs were assessed by the expert group.

CONCLUSIONS

Swe-ABS is a simplified method to quantify the anticholinergic burden and is easy to use in clinical practice. Publication of this scale might make clinicians more aware of drugs with anticholinergic properties and patients' total anticholinergic burden. Further research is needed to validate the Swe-ABS and evaluate anticholinergic exposure versus clinically significant outcomes.

The Impact of Muscarinic Antagonism on Psychosis-Relevant Behaviors and Striatal [11C] Raclopride Binding in Tau Mouse Models of Alzheimer's Disease

Psychosis that occurs over the course of Alzheimer's disease (AD) is associated with increased caregiver burden and a more rapid cognitive and functional decline. To find new treatment targets, studies modeling psychotic conditions traditionally employ agents known to induce psychosis, utilizing outcomes with cross-species relevance, such as locomotive activity and sensorimotor gating, in rodents. In AD, increased burdens of tau pathology (a diagnostic hallmark of the disease) and treatment with anticholinergic medications have, separately, been reported to increase the risk of psychosis. Recent evidence suggests that muscarinic antagonists may increase extracellular tau. Preclinical studies in AD models have not previously utilized muscarinic cholinergic antagonists as psychotomimetic agents. In this report, we utilize a human-mutant-tau model (P301L/COMTKO) and an over-expressed non-mutant human tau model (htau) in order to compare the impact of antimuscarinic (scopolamine 10 mg/kg/day) treatment with dopaminergic (reboxetine 20 mg/kg/day) treatment, for 7 days, on locomotion and sensorimotor gating. Scopolamine increased spontaneous locomotion, while reboxetine reduced it; neither treatment impacted sensorimotor gating. In the P301L/COMTKO, scopolamine treatment was associated with decreased muscarinic M4 receptor expression, as quantified with RNA-seq, as well as increased dopamine receptor D2 signaling, as estimated with Micro-PET [11C] raclopride binding. Scopolamine also increased soluble tau in the striatum, an effect that partially mediated the observed increases in locomotion. Studies of muscarinic agonists in preclinical tau models are warranted to determine the impact of treatment-on both tau and behavior-that may have relevance to AD and other tauopathies.

Anticholinergic burden in middle and older age is associated with lower cognitive function, but not with brain atrophy

AIMS

The aim of this study is to estimate the association between anticholinergic burden, general cognitive ability and various measures of brain structural MRI in relatively healthy middle-aged and older individuals.

METHODS

In the UK Biobank participants with linked health-care records (n = 163,043, aged 40-71 at baseline), of whom about 17 000 had MRI data available, we calculated the total anticholinergic drug burden according to 15 different anticholinergic scales and due to different classes of drugs. We then used linear regression to explore the associations between anticholinergic burden and various measures of cognition and structural MRI, including general cognitive ability, 9 separate cognitive domains, brain atrophy, volumes of 68 cortical and 14 subcortical areas and fractional anisotropy and median diffusivity of 25 white-matter tracts.

RESULTS

Anticholinergic burden was modestly associated with poorer cognition across most anticholinergic scales and cognitive tests (7/9 FDR-adjusted significant associations, standardised betas (β) range: -0.039, -0.003). When using the anticholinergic scale exhibiting the strongest association with cognitive functions, anticholinergic burden due to only some classes of drugs exhibited negative associations with cognitive function, with β-lactam antibiotics (β = -0.035, PFDR < 0.001) and opioids (β = -0.026, PFDR < 0.001) exhibiting the strongest effects. Anticholinergic burden was not associated with any measure of brain macrostructure or microstructure (PFDR > 0.08).

CONCLUSIONS

Anticholinergic burden is weakly associated with poorer cognition, but there is little evidence for associations with brain structure. Future studies might focus more broadly on polypharmacy or more narrowly on distinct drug classes, instead of using purported anticholinergic action to study the effects of drugs on cognitive ability.

Cholinergic Antagonists and Behavioral Disturbances in Neurodegenerative Diseases

Cholinergic antagonists interfere with synaptic transmission in the central nervous system and are involved in pathological processes in patients with neurocognitive disorders (NCD), such as behavioral and psychological symptoms of dementia (BPSD). In this commentary, we will briefly review the current knowledge on the impact of cholinergic burden on BPSD in persons with NCD, including the main pathophysiological mechanisms. Given the lack of clear consensus regarding symptomatic management of BPSD, special attention must be paid to this preventable, iatrogenic condition in patients with NCD, and de-prescription of cholinergic antagonists should be considered in patients with BPSD.

Evaluation of the association of anticholinergic burden and delirium in older hospitalised patients - A cohort study comparing 19 anticholinergic burden scales

AIMS

A recent review identified 19 anticholinergic burden scales (ABSs) but no study has yet compared the impact of all 19 ABSs on delirium. We evaluated whether a high anticholinergic burden as classified by each ABS is associated with incident delirium.

METHOD

We performed a retrospective cohort study in a Swiss tertiary teaching hospital using data from 2015-2018. Included were patients aged ≥65, hospitalised ≥48 hours with no stay >24 hours in intensive care. Delirium was defined twofold: (i) ICD-10 or CAM and (ii) ICD-10 or CAM or DOSS. Patients' cumulative anticholinergic burden score, calculated within 24 hours after admission, was classified using a binary (<3: low, ≥3: high burden) and a categorical approach (0: no, 0.5-3: low, ≥3: high burden). Association was analysed using multivariable logistic regression.

RESULTS

Over 25 000 patients (mean age 77.9 ± 7.6 years) were included. Of these, (i) 864 (3.3%) and (ii) 2770 (11.0%) developed delirium. Depending on the evaluated ABS, 4-63% of the patients were exposed to at least one anticholinergic drug. Out of 19 ABSs, (i) 14 and (ii) 16 showed a significant association with the outcomes. A patient with a high anticholinergic burden score had odds ratios (ORs) of 1.21 (95% confidence interval [CI]: 1.03-1.42) to 2.63 (95% CI: 2.28-3.03) for incident delirium compared to those with low or no burden.

CONCLUSION

A high anticholinergic burden within 24 hours after admission was significantly associated with incident delirium. Although prospective studies need to confirm these results, discontinuing or substituting drugs with a score of ≥3 at admission might be a targeted intervention to reduce incident delirium.

Association between anticholinergic burden and dementia in UK Biobank

Background

Previous studies on the relationship between anticholinergic drugs and dementia have reported heterogeneous results. This variability could be due to different anticholinergic scales and differential effects of distinct classes of drugs.

Methods

Using Cox proportional hazards models, we computed the association between annual anticholinergic burden (AChB) and the risk of dementia in UK Biobank with linked general practitioner prescription records between the years 2000 and 2015 (n = 171,775).

Results

AChB according to most anticholinergic scales (standardized odds ratio range: 1.027-1.125) and the slope of the AChB trajectory (hazard ratio = 1.094; 95% confidence interval: 1.068-1.119) were predictive of dementia. However, the association between AChB and dementia held only for some classes of drugs, especially antidepressants, antiepileptics, and antidiuretics.

Discussion

The heterogeneity in previous findings may partially be due to different effects for different classes of drugs. Future studies should establish differences in more detail and further examine the practicality of a general measure of AChB relating to the risk of dementia.

[Anticholinergic scales: Use in psychiatry and update of the anticholinergic impregnation scale]

Anticholinergic properties are well known to prescribers, notably in mental health, as a therapeutic strategy for i.e. extrapyramidal syndrome but also as a source of numerous adverse side effects. Herein, we propose a narrative literature review describing: (i) cholinergic pharmacology and anticholinergic properties; (ii) the importance of anticholinergic therapeutic properties in psychiatry; (iii) the existing anticholinergic drug scales and their usage limitations in Psychiatry and; last (iv) an update to the anticholinergic drug impregnation scale, designed for the French psychiatry practice. The anticholinergic side effects can appear both in the peripheral level (dry mouth, constipation, etc.) and in the central level (especially as cognitive deficits). Many of the so called « anticholinergic » drugs are in fact entirely or mostly antimuscarinic and act essentially as parasympathetic system antagonists. Overall, anticholinergic/antimuscarinic side effects are usually attributed to psychotropic medications: to certain antipsychotics, notably classical neuroleptics such as phenothiazine and also to tricyclic antidepressants. In practice, the impact of anticholinergic toxicity treatments is often highlighted due to their excessively prolonged use in patients on antipsychotics. Interestingly, these antipsychotic treatments are better known for their anticholinergic side effects, especially cognitive ones, with an early onset specially in elder patients and/or in the case of polymedication. In order to evaluate anticholinergic side effects, metrics known as anticholinergic burden scales were created in the last few decades. Nowadays, 13 different scales are documented and accepted by the international academic community, but only three of them are commonly used: the Anticholinergic Drug Scale (ADS), the Anticholinergic Risk Scale (ARS) and the Anticholinergic Burden Scale (ACB). All of them are based on a similar principle, consisting of grading treatments individually, and they are normally scored from 0 - no presence of side effects - to 3 - anticholinergic effects considered to be strong or very strong. Using these scales enables the calculation of the so-called "anticholinergic burden", which corresponds to the cumulative effect of using multiple medications with anticholinergic properties simultaneously. The application of anticholinergic scales to patients with psychiatric disorders has revealed that schizophrenic patients seem to be especially sensitive to anticholinergic cognitive side effects, while elder and depressed patients were more likely to show symptoms of dementia when exposed to higher anticholinergic burden. Unfortunately, these tools appear to have a low parallel reliability, and so they might induce large differences when assessing side effects predictability. In addition, the capacity of these scales to predict central adverse effects is limited due to the fact they poorly or do not differentiate, the ability of treatments to cross the blood-brain barrier. Finally, one last limitation on the validity of these scales is prescription posology is not accounted for side effects considered to be dose dependent. Recently, the MARANTE (Muscarinic Acetylcholine Receptor ANTagonist Exposure) scale has incorporated an anticholinergic burden weighting by posology. Nevertheless, this new model can be criticized, due to the limited number of medications included and due to testing a limited number of potency ranges and dosages for each treatment. Herein, we propose an update to the Anticholinergic Impregnation Scale, developed specifically for the French Psychiatry practice. The scale validation was based on an evaluation of the prescriptions correcting anticholinergic peripheral side effects (constipation, xerostomia and xeropthalmia). This indirect evaluation allowed us to show patients with an anticholinergic impregnation score higher than 5 received significantly more treatments for constipation and xerostomia. This strategy bypasses the bias of a cognitive evaluation in patients with severe mental health disorders. Moreover, the relevance of a tool developed specifically for French psychiatry is justified by the fact that some highly prescribed treatments for mental illness in France (cyamemazine and tropatemine) are strong anticholinergics, and also by the fact they are rarely included in the existing anticholinergic scales. This update of the original scale, published in 2017, includes information whether prescribed drugs cross the blood-brain barrier and thus makes possible a more accurate assessment when evaluating anticholinergic central side effects. Finally, the anticholinergic impregnation scale will soon be integrated into a prescription help software, which is currently being developed to take into consideration dose dependent adverse effects.

High anticholinergic burden at admission associated with in-hospital mortality in older patients: A comparison of 19 different anticholinergic burden scales

Although no gold standard exists to assess a patient's anticholinergic burden, a review identified 19 anticholinergic burden scales (ABSs). No study has yet evaluated whether a high anticholinergic burden measured with all 19 ABSs is associated with in‐hospital mortality and length of stay (LOS). We conducted a cohort study at a Swiss tertiary teaching hospital using patients' electronic health record data from 2015–2018. Included were patients aged ≥65 years, hospitalised ≥48 h without stays and >24 h in intensive care. Patients' cumulative anticholinergic burden score was classified using a binary (<3: low, ≥3: high) and categorical approach (0: no, 0.5–3: low, ≥3: high). In‐hospital mortality and LOS were analysed using multivariable logistic and linear regression, respectively. We included 27,092 patients (mean age 78.0 ± 7.5 years, median LOS 6 days). Of them, 913 died. Depending on the evaluated ABS, 1370 to 17,035 patients were exposed to anticholinergics. Patients with a high burden measured by all 19 ABSs were associated with a 1.32‐ to 3.03‐fold increase in in‐hospital mortality compared with those with no/low burden. We obtained similar results for LOS. To conclude, discontinuing drugs with anticholinergic properties (score ≥3) at admission might be a targeted intervention to decrease in‐hospital mortality and LOS.

Increase in anticholinergic burden from 1990 to 2015: Age-period-cohort analysis in UK biobank

BACKGROUND

The use of prescription drugs with anticholinergic properties has been associated with multiple negative health outcomes in older people. Moreover, recent evidence suggests that associated adverse effects may occur even decades after stopping anticholinergic use. Despite the implicated importance of examining longitudinal patterns of anticholinergic prescribing for different age groups, few such data are available.

METHODS

We performed an age-period-cohort (APC) analysis to study trends in an aggregate measure of anticholinergic burden between the years 1990 and 2015, utilising data from >220 000 UK Biobank participants with linked prescription data from primary care.

RESULTS

Anticholinergic burden in the sample increased up to 9-fold over 25 years and was observed for both period and age effects across most classes of drugs. The greatest increase was seen in the prescribing of antidepressants. Female sex, lower education and greater deprivation were associated with greater anticholinergic burden.

CONCLUSIONS

The increase in anticholinergic prescribing is mostly due to an increase in polypharmacy and is attributable to both ageing of participants and period-related changes in prescribing practices. Research is needed to clarify the implications of rising anticholinergic use for public health and to contextualise this rise in light of other relevant prescribing practices.

Quality of anticholinergic burden scales and their impact on clinical outcomes: a systematic review

PURPOSE

Older people are at risk of anticholinergic side effects due to changes affecting drug elimination and higher sensitivity to drug's side effects. Anticholinergic burden scales (ABS) were developed to quantify the anticholinergic drug burden (ADB). We aim to identify all published ABS, to compare them systematically and to evaluate their associations with clinical outcomes.

METHODS

We conducted a literature search in MEDLINE and EMBASE to identify all published ABS and a Web of Science citation (WoS) analysis to track validation studies implying clinical outcomes. Quality of the ABS was assessed using an adapted AGREE II tool. For the validation studies, we used the Newcastle-Ottawa Scale and the Cochrane tool Rob2.0. The validation studies were categorized into six evidence levels based on the propositions of the Oxford Center for Evidence-Based Medicine with respect to their quality. At least two researchers independently performed screening and quality assessments.

RESULTS

Out of 1297 records, we identified 19 ABS and 104 validations studies. Despite differences in quality, all ABS were recommended for use. The anticholinergic cognitive burden (ACB) scale and the German anticholinergic burden scale (GABS) achieved the highest percentage in quality. Most ABS are validated, yet validation studies for newer scales are lacking. Only two studies compared eight ABS simultaneously. The four most investigated clinical outcomes delirium, cognition, mortality and falls showed contradicting results.

CONCLUSION

There is need for good quality validation studies comparing multiple scales to define the best scale and to conduct a meta-analysis for the assessment of their clinical impact.

Association between anticholinergic burden and anticholinergic adverse outcomes in the elderly: Pharmacological basis of their predictive value for adverse outcomes

The use of anticholinergic drugs and other drugs with anticholinergic activity is highly prevalent in older people. Cumulative anticholinergic effects, known as anticholinergic burden, are associated with important peripheral and central adverse effects and outcomes. Several methods have been developed to quantify anticholinergic burden and to estimate the risk of adverse anticholinergic effects. Serum anticholinergic activity (SAA) and anticholinergic burden scoring systems are the most commonly used methods to predict the occurrence of important negative outcomes. These tools could guide clinicians in making more rational prescriptions to enhance patient safety, especially in older people. However, the literature has reported conflicting results about the predictive ability of these tools. The majority of these instruments ignore relevant pharmacologic aspects such as the doses used, differential muscarinic receptor subtype affinities, and blood-brain barrier permeability. To increase the clinical relevance of these tools, mechanistic and clinical pharmacology should collaborate. This narrative review describes the rational and pharmacological basis of anticholinergic burden tools and provides insight about their predictive value for adverse outcomes.

Quality of anticholinergic burden scales and their impact on clinical outcomes: a systematic review

Purpose

Older people are at risk of anticholinergic side effects due to changes affecting drug elimination and higher sensitivity to drug’s side effects. Anticholinergic burden scales (ABS) were developed to quantify the anticholinergic drug burden (ADB). We aim to identify all published ABS, to compare them systematically and to evaluate their associations with clinical outcomes.

Methods

We conducted a literature search in MEDLINE and EMBASE to identify all published ABS and a Web of Science citation (WoS) analysis to track validation studies implying clinical outcomes. Quality of the ABS was assessed using an adapted AGREE II tool. For the validation studies, we used the Newcastle-Ottawa Scale and the Cochrane tool Rob2.0. The validation studies were categorized into six evidence levels based on the propositions of the Oxford Center for Evidence-Based Medicine with respect to their quality. At least two researchers independently performed screening and quality assessments.

Results

Out of 1297 records, we identified 19 ABS and 104 validations studies. Despite differences in quality, all ABS were recommended for use. The anticholinergic cognitive burden (ACB) scale and the German anticholinergic burden scale (GABS) achieved the highest percentage in quality. Most ABS are validated, yet validation studies for newer scales are lacking. Only two studies compared eight ABS simultaneously. The four most investigated clinical outcomes delirium, cognition, mortality and falls showed contradicting results.

Conclusion

There is need for good quality validation studies comparing multiple scales to define the best scale and to conduct a meta-analysis for the assessment of their clinical impact.

Electronic supplementary material

The online version of this article (10.1007/s00228-020-02994-x) contains supplementary material, which is available to authorized users.

The role of nicotinic cholinergic neurotransmission in delusional thinking

Delusions are a difficult-to-treat and intellectually fascinating aspect of many psychiatric illnesses. Although scientific progress on this complex topic has been challenging, some recent advances focus on dysfunction in neural circuits, specifically in those involving dopaminergic and glutamatergic neurotransmission. Here we review the role of cholinergic neurotransmission in delusions, with a focus on nicotinic receptors, which are known to play a part in some illnesses where these symptoms appear, including delirium, schizophrenia spectrum disorders, bipolar disorder, Parkinson, Huntington, and Alzheimer diseases. Beginning with what we know about the emergence of delusions in these illnesses, we advance a hypothesis of cholinergic disturbance in the dorsal striatum where nicotinic receptors are operative. Striosomes are proposed to play a central role in the formation of delusions. This hypothesis is consistent with our current knowledge about the mechanism of action of cholinergic drugs and with our abstract models of basic cognitive mechanisms at the molecular and circuit levels. We conclude by pointing out the need for further research both at the clinical and translational levels.

Animal Models of Psychosis in Alzheimer Disease

Psychosis in Alzheimer Disease (AD) represents a distinct clinicopathologic variant associated with increased cognitive and functional morbidity and an accelerated disease course. To date, extant treatments offer modest benefits with significant risks. The development of new pharmacologic treatments for psychosis in AD would be facilitated by validated preclinical models with which to test candidate interventions. The current review provides a brief summary of the process of validating animal models of human disease together with a critical analysis of the challenges posed in attempting to apply those standards to AD-related behavioral models. An overview of phenotypic analogues of human cognitive and behavioral impairments, with an emphasis on those relevant to psychosis, in AD-related mouse models is provided, followed by an update on recent progress in efforts to translate findings in the pathophysiology of psychotic AD into novel models. Finally, some future directions are suggested to expand the catalogue of psychosis-relevant phenotypes that may provide a sturdier framework for model development and targets for preclinical treatment outcomes.

Association between anticholinergic drug burden and mortality in older people: a systematic review

PURPOSE

The purpose of the study is to conduct a systematic review of studies examining the association between anticholinergic burden and mortality in older individuals.

METHODS

A literature search was performed to identify relevant studies, using MEDLINE, EMBASE, PsycINFO and CENTRAL, from January 1990 to December 2018. We included studies of patients with a mean age of 65 years or older where the anticholinergic burden was estimated using anticholinergic risk assessment tools, and associations between anticholinergic load and mortality were investigated. The primary outcome of interest was the association between anticholinergic burden and mortality.

RESULTS

Twenty-seven studies were included. These were three cross-sectional, one nested case-control and 23 prospective or retrospective cohort studies. Most studies were determined to be of good quality. A total of 15 studies reported a positive correlation between anticholinergic burden and mortality, while the remaining 10 studies did not report a significant association. Eighteen out of 27 studies (80%) had a short follow-up period of 1 year or less. Among the five high-quality studies that met all the domains of the quality assessment criteria, four showed a positive association.

CONCLUSION

The variation in results could relate to the quality of the studies, follow-up period, anticholinergic risk assessment tool used and the study setting. Sixty-three percent (n = 17) of all the included studies, but almost all of the high-quality studies with an extended follow-up, reported a positive correlation between anticholinergic burden and mortality. Further high-quality research, using standardized measures and with adequate follow-up periods, is required to confirm the relationship between anticholinergic burden and mortality.

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.

Threshold for a Reduction in Anticholinergic Burden to Decrease Behavioral and Psychological Symptoms of Dementia

BACKGROUND

A high anticholinergic burden (AB) is associated with the occurrence of behavioral and psychological symptoms (BPSDs), which are frequent in dementia.

OBJECTIVES

Our aim was to determine the threshold for a reduction in AB that would lead to a clinically significant improvement in BPSDs (in terms of frequency, severity, and disruptiveness).

DESIGN

A single-center prospective study.

SETTINGS

Dedicated geriatric care unit specializing in the management of patients with dementia.

PARTICIPANTS

The study involved older patients with dementia, hospitalized for management of BPSDs.

METHODS

One hundred forty-seven patients were included (mean age = 84.1 ± 5.2 years). The AB was assessed using 3 scales, namely, the Anticholinergic Drug Scale (ADS), the Anticholinergic Cognitive Burden scale (ACB), and the Anticholinergic Risk Scale (ARS). A clinically significant improvement in BPSDs was defined as a reduction of 4 points in the frequency × severity (F×S) score of the Neuropsychiatric Inventory-Nursing Home (NPI-NH) questionnaire. The threshold for a reduction in AB that corresponded to a clinically significant improvement in BPSDs was determined by multiple linear regression.

RESULTS

One hundred forty-seven patients were included (mean age = 84.1 ± 5.2 years). Using the ADS, a reduction of 2 points in AB in patients with moderate-intensity BPSDs was associated with a clinically significant improvement in the F×S score of the NPI-NH [6.34, 95% confidence interval (CI) 4.54-8.14], and a reduction of 3 points was associated with a clinically significant improvement in the occupational disruptiveness score (4.26, 95% CI 3.11-5.41).

CONCLUSIONS/IMPLICATIONS

In older patients with dementia presenting BPSDs, the risk-benefit ratio of anticholinergic drugs is debatable and, where possible, drugs with a lower AB would be preferable. Because BPSDs are a frequent cause of hospitalization, a standardized approach to analysis and reduction of AB is warranted in this population. Depending on the scale used to assess anticholinergic burden (AB), a small reduction in AB is associated with a decrease in frequency, severity, and disruptiveness of moderate-intensity BPSDs. Drugs with a high AB should be avoided where possible in older patients with dementia, and drugs with a lower AB would be preferable. Heterogeneity between the assessment scales for AB precludes generalization of the impact of a reduction in AB on BPSDs.

An anticholinergic burden score for German prescribers: score development

Background

Anticholinergic drugs put elderly patients at a higher risk for falls, cognitive decline, and delirium as well as peripheral adverse reactions like dry mouth or constipation. Prescribers are often unaware of the drug-based anticholinergic burden (ACB) of their patients. This study aimed to develop an anticholinergic burden score for drugs licensed in Germany to be used by clinicians at prescribing level.

Methods

A systematic literature search in pubmed assessed previously published ACB tools. Quantitative grading scores were extracted, reduced to drugs available in Germany, and reevaluated by expert discussion. Drugs were scored as having no, weak, moderate, or strong anticholinergic effects. Further drugs were identified in clinical routine and included as well.

Results

The literature search identified 692 different drugs, with 548 drugs available in Germany. After exclusion of drugs due to no systemic effect or scoring of drug combinations (n = 67) and evaluation of 26 additional identified drugs in clinical routine, 504 drugs were scored. Of those, 356 drugs were categorised as having no, 104 drugs were scored as weak, 18 as moderate and 29 as having strong anticholinergic effects.

Conclusions

The newly created ACB score for drugs authorized in Germany can be used in daily clinical practice to reduce potentially inappropriate medications for elderly patients. Further clinical studies investigating its effect on reducing anticholinergic side effects are necessary for validation.

Electronic supplementary material

The online version of this article (10.1186/s12877-018-0929-6) contains supplementary material, which is available to authorized users.

[Atropinic burden and anticholinergic drugs: Interest and application in clinical practice in the elderly]

Anticholinergic drugs (also called antimuscarinics or atropinics) increase the risk of falls, cognitive impairment and/or mortality in older patients. These drugs belong to the lists of potentially inappropriate medications in the elderly. The aim of this review was to present and discuss the different tools available to measure the atropinic risk in drug exposure of older patients. Several scales, developed from biological and/or clinical criteria, allow to classify anticholinergic drugs according to their atropinic potency and to assign to them an atropinic burden. Total atropinic burden of patient drug exposure can be calculated as the sum of atropinic score of each drug. Other tools include drug daily doses to better estimate the atropinic risk. These different methods are a precious help to decrease atropinic exposure in the elderly. Nevertheless, they have to be considered as upgradable and it is necessary to adapt them regularly according to the introduction of new drugs in clinical practice.

Comparison of Nine Instruments to Calculate Anticholinergic Load in a Large Cohort of Older Outpatients: Association with Cognitive and Functional Decline, Falls, and Use of Laxatives

OBJECTIVE

A patient's risk for anticholinergic adverse effects is frequently estimated by instruments evaluating the drugs included in his medication profile. It remains unknown, however, which characteristics should be included in such an assessment instrument aiming to reliably predict adverse anticholinergic outcomes.

DESIGN

Cross-sectional study.

SETTING

ESTHER cohort (Germany).

PARTICIPANTS

Home-dwelling participants (N = 2,761) aged between 60 and 87 years.

MEASUREMENTS

The association between anticholinergic load calculated with nine different instruments and four anticholinergic adverse outcomes was investigated in univariate and multivariate analyses. Therefore, linear models complemented with Kendall's tau rank correlation coefficients (ԏ) were applied for continuous outcomes and generalized linear models were used to derive odds ratios (ORs) with 95% confidence intervals (CIs) for binary endpoints.

RESULTS

Based on the respective identification criteria for anticholinergic drugs, the nine instruments identified between 245 (9%) and 866 (31%) anticholinergic drug users (mean age ± SD: 73 ± 6 years; Mini-Mental State Examination [MMSE] score: 28.3 ± 2.07; Barthel Index: 97.1 ± 7.5; 291 reporting falls; 29 taking laxatives [surrogate for constipation]). In the multivariate analysis, only two instruments indicated a significant association between anticholinergic load and all four outcomes. The instrument considering the prescribed dose showed the strongest association with MMSE scores (ԏ = -0.10), falls (OR: 2.30; 95% CI: 1.50-3.52), and the use of laxatives (OR: 3.11; 95% CI: 1.04-9.36).

CONCLUSIONS

Instruments most reliably predicted anticholinergicadverse events if they were either based on the drugs' serum anticholinergic activity and the suggestions of clinician experts or considered the actual prescribed dose.

Limitations of the Anticholinergic Activity Assay and Assay-Based Anticholinergic Drug Scales

OBJECTIVE

The anticholinergic activity (AA) assay is a common method to determine a patient's anticholinergic load. Several limitations, however, are expected when applying the AA assay to patients or using drug scales to estimate anticholinergic burden based on AA levels. This study aims to demonstrate common pitfalls in an experimental setting and outline their clinical consequences.

METHODS

The AA was analyzed for five drugs with reported interaction with muscarinic receptors. Concentration-response curves were constructed for furosemide (weak anticholinergic), diphenhydramine (moderate anticholinergic), the strong anticholinergic amitriptyline and its metabolite nortriptyline, and the cholinergic pilocarpine. The Combination Index (CI) was used to assess the interaction of three drug combinations with amitriptyline.

RESULTS

All compounds displaced the radioactive tracer from its receptor binding site in a concentration-dependent manner, and full displacement was reached for all compounds except furosemide (E_max 16%). The CI indicated that amitriptyline and thioridazine have antagonistic effects (CI = 1.46) at low and synergistic effects (CI = 0.88) at higher concentrations (p < 0.0001), whereas synergistic effects (CI = 0.47-0.48) were observed for amitriptyline in any concentration combined with pilocarpine (p < 0.001).

CONCLUSION

When the patient's anticholinergic load is estimated using AA levels, the actual exposure, combination of anticholinergic drugs, their active metabolites, and also drugs with an opposite pharmacologic action will contribute to AA levels, whereas weak anticholinergic drugs in therapeutic concentrations are rather negligible.

Anticholinergic drugs and negative outcomes in the older population: from biological plausibility to clinical evidence

The use of medication with anticholinergic properties is widespread among older subjects. Many drugs of common use such as antispasmodics, bronchodilators, antiarrhythmics, antihistamines, anti-hypertensive drugs, antiparkinson agents, skeletal muscle relaxants, and psychotropic drugs have been demonstrated to have an anticholinergic activity. The most frequent adverse effects are dry mouth, nausea, vomiting, constipation, abdominal pain, urinary retention, blurred vision, tachycardia and neurologic impairment such as confusion, agitation and coma. A growing evidence from experimental studies and clinical observations suggests that drugs with anticholinergic properties can cause physical and mental impairment in the elderly population. However, the morbidity and management issues associated with unwanted anticholinergic activity are underestimated and frequently overlooked. Moreover, their possible relation with specific negative outcome in the elderly population is still not firmly established. The aim of the present review was to evaluate the relationship between the use of drugs with anticholinergic activity and negative outcomes in older persons. We searched PubMed and Cochrane combining the search terms "anticholinergic", "delirium", "cognitive impairment", "falls", "mortality" and "discontinuation". Medicines with anticholinergic properties may increase the risks of functional and cognitive decline, morbidity, institutionalization and mortality in older people. However, such evidences are still not conclusive probably due to possible confounding factors. In particular, more studies are needed to investigate the effects of discontinuation of drug with anticholinergic properties. Overall, minimizing anticholinergic burden should always be encouraged in clinical practice to improve short-term memory, confusion and delirium, quality of life and daily functioning.

Different methods, different results--how do available methods link a patient's anticholinergic load with adverse outcomes?

PURPOSE

Anticholinergic drugs are known to cause physical and cognitive impairment, particularly in older patients. The total of all anticholinergic influences to which a patient is exposed is referred to as anticholinergic load. Because the anticholinergic load is defined in various ways, this review aimed to describe differences in the development and evaluation of available methods calculating the anticholinergic load.

METHODS

From September 2014 to August 2015, two reviewers performed a literature search in PubMed considering relevant items of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline. We aimed to identify articles which calculated the anticholinergic load with a scale or equation and investigated its association with patient-related outcomes. From the included studies, we descriptively analyzed the identification and scoring criteria of the scales and equations with a main emphasis on their association to the reported outcomes.

RESULTS

Out of 465 articles, 55 were included referring to 12 scales and one equation. Main discrepancies were located in eight different identification criteria for anticholinergic drugs, two different scoring principles, and 118 tests used for assessing outcomes. The methods most frequently detecting a significant association between the anticholinergic load and outcomes took into account the drugs' dosages and anticholinergic potencies. Interestingly, none of the methods included the patient's susceptibility for anticholinergic effects and they only rarely considered modulators of drug exposure.

CONCLUSIONS

Due to hugely varying tests for assessing outcomes, the methods are scarcely comparable. For a more valuable comparison, the anticholinergic load should be calculated with all scales and the equation and correlated with patient-related outcomes.

Cognitive risks of anticholinergics in the elderly

Many drugs commonly prescribed to the elderly have anticholinergic properties. Due to the current clinical use of drugs with mild-to-modest anticholinergic activity, the clinical manifestations of anticholinergic toxicity are likely to be nonspecific (e.g., cognitive impairment) and reflect the effects of cumulative anticholinergic burden. Age-associated physiological and pharmacokinetic changes increase anticholinergic drug effects in later life. Those with cognitive impairment and neurodegeneration are particularly susceptible to anticholinergic toxicity. Recent findings suggest that chronic anticholinergic burden may hasten or contribute to a neurodegenerative process. APOE ε4 carrier status may be a genetic risk factor for vulnerability to negative anticholinergic effects. There is no clinically available laboratory test to assess anticholinergic levels. Clinicians need to be cognizant of anticholinergic risks in later life. The use of clinical scales (e.g., Anticholinergic Drug Scale) and consensus guidelines (e.g., Revised Beers Criteria) may be helpful.

Capturing side-effect of medication to identify persons at risk of delirium

Delirium, an acute confusional state characterized by decline in attention and cognition, is a common, life-threatening, but potentially preventable clinical syndrome among older persons. Deficits in cholinergic function have been postulated to cause delirium and cognitive decline. In particular, an imbalance between levels of acetylcholine and monoamine (such as dopamine) may cause delirium. We describe two cases of delirium in hospitalized older patients, supporting the "cholinergic deficiency hypothesis". In the first patient, hypo-reactive delirium developed a few hours after a dose of the long-acting opiate tramadol (a drug with anticholinergic effect) as analgesic for pain related to advanced peripheral artery disease. In the second patient, with vascular parkinsonism plus pre-frontal cortex vascular lesions, hyper-reactive delirium developed a few hours after a prescribed administration of L-dopa. These symptoms disappeared completely on the following day. These two "natural" experiments support the hypothesis that both hypo-reactive and hyper-active delirium may be caused by a reduction in cholinergic signaling.

Review on pharmacokinetics and pharmacodynamics and the aging kidney

In people who are aged >65 years, pharmacokinetics are influenced more by the loss of kidney function than by the aging process of any other organ. A GFR of 30 to 60 ml/min, suggestive of stage 3 kidney disease, is observed in 15 to 30% of elderly people. Drug dosing must be adjusted to both changing pharmacokinetics and pharmacodynamics; the pharmacodynamics might be influenced by the aging of other organs, too. Using our NEPharm database, we extracted abstracts with pharmacokinetic parameters since 1999 from a weekly PubMed search. The recorded data were analyzed and compared with published recommendations on drug dosage and use in the elderly. Purely age-related changes in pharmacokinetic parameters were recorded from publications on 127 drugs. The analysis of our NEPharm records revealed an average (mean +/- SD) age-related prolongation of half-life of 1.39-fold (corresponding to +39 +/- 61%). Contrasting to common opinion, mean changes in clearance (-1 +/- 54%) and volume of distribution (+24 +/- 56%) were even less. The modest changes in pharmacokinetics do not suggest general dosage modifications in the elderly for most drugs. Changes in pharmacodynamics justify the common medication rule in the elderly-"start low + go slow"-especially for drugs that act on the central nervous system; however, in the case of anti-infective and anticancer therapy, the rule should be "hit hard = start high + go fast" to produce the target effect also in the elderly.

Drugs with anticholinergic properties, cognitive decline, and dementia in an elderly general population: the 3-city study

BACKGROUND

Despite the high intake of medications with anticholinergic properties by community-dwelling elderly persons, the effects on cognitive decline and dementia have rarely been evaluated.

METHODS

Participants were 4128 women and 2784 men 65 years or older from a population-based cohort recruited from 3 French cities. Cognitive performance, clinical diagnosis of dementia, and anticholinergic use were evaluated at baseline and 2 and 4 years later.

RESULTS

A total of 7.5% of the participants reported anticholinergic drug use at baseline. Multivariate-adjusted logistic regression indicated that women reporting use of anticholinergic drugs at baseline showed greater decline over 4 years in verbal fluency scores (odds ratio [OR], 1.41; 95% confidence interval [CI], 1.11-1.79) and in global cognitive functioning (OR, 1.22; 95% CI, 0.96-1.55) than women not using anticholinergic drugs. In men, an association was found with decline in visual memory (OR, 1.63; 95% CI, 1.08-2.47) and to a lesser extent in executive function (OR, 1.47; 95% CI, 0.89-2.44). Notable interactions were observed in women between anticholinergic use and age, apolipoprotein E, or hormone therapy. A 1.4- to 2-fold higher risk of cognitive decline was observed for those who continuously used anticholinergic drugs but not for those who had discontinued use. The risk of incident dementia over the 4-year follow-up period was also increased in continuous users (hazard ratio [HR], 1.65; 95% CI, 1.00-2.73) but not in those who discontinued the use of anticholinergic drugs (HR, 1.28; 95% CI, 0.59-2.76).

CONCLUSIONS

Elderly people taking anticholinergic drugs were at increased risk for cognitive decline and dementia. Discontinuing anticholinergic treatment was associated with a decreased risk. Physicians should carefully consider prescription of anticholinergic drugs in elderly people, especially in the very elderly and in persons at high genetic risk for cognitive disorder.

Drugs with anticholinergic properties: cognitive and neuropsychiatric side-effects in elderly patients

Drug consumption in older people is usually high and many prescribed medications have unsuspected anticholinergic (ACH) (Table 1) properties. Drug induced ACH side-effects are particularly severe in aging brain and even more in demented patients. This review will focus on the association between ACH drug intake and the risk of developing central nervous system side-effects in elderly people. The threat of developing cognitive impairment, psychosis and delirium will be particularly analyzed.

Drugs with anticholinergic properties as a risk factor for cognitive impairment in elderly people: a population-based study

Prevention of drug-related problems is a key issue in the aged. Anticholinergic (ACH) drugs are a biologically plausible and potentially modifiable risk factor for cognitive impairment. Therefore, we intended to evaluate the association between ACH drugs and cognitive impairment. Our study comprised 750 subjects aged 65 years or older. Cognitive impairment was evaluated using Mini-Mental State Examination and Global Deterioration Scale. Patients were classified into ACH-drug users and non-ACH-drug users. Those using ACH drugs (20.1%) were more likely to have cognitive impairment than those using non-ACH drugs (odds ratio, 3.18; 95% confidence interval, 1.93-5.23; P < 0.001); this association remained significant even after adjusting for potential confounding variables (odds ratio, 2.30; 95% confidence interval, 1.19-4.45). Our data suggest that ACH drug intake should be regarded a potentially modifiable risk factor for cognitive impairment in the elderly.