Anticholinergics and clinical outcomes amongst people with pre-existing dementia: A systematic review

An Evidence-Based Update on Anticholinergic Use for Drug-Induced Movement Disorders

Drug-induced movement disorders (DIMDs) are associated with use of dopamine receptor blocking agents (DRBAs), including antipsychotics. The most common forms are drug-induced parkinsonism (DIP), dystonia, akathisia, and tardive dyskinesia (TD). Although rare, neuroleptic malignant syndrome (NMS) is a potentially life-threatening consequence of DRBA exposure. Recommendations for anticholinergic use in patients with DIMDs were developed on the basis of a roundtable discussion with healthcare professionals with extensive expertise in DIMD management, along with a comprehensive literature review. The roundtable agreed that "extrapyramidal symptoms" is a non-specific term that encompasses a range of abnormal movements. As such, it contributes to a misconception that all DIMDs can be treated in the same way, potentially leading to the misuse and overprescribing of anticholinergics. DIMDs are neurobiologically and clinically distinct, with different treatment paradigms and varying levels of evidence for anticholinergic use. Whereas evidence indicates anticholinergics can be effective for DIP and dystonia, they are not recommended for TD, akathisia, or NMS; nor are they supported for preventing DIMDs except in individuals at high risk for acute dystonia. Anticholinergics may induce serious peripheral adverse effects (e.g., urinary retention) and central effects (e.g., impaired cognition), all of which can be highly concerning especially in older adults. Appropriate use of anticholinergics therefore requires careful consideration of the evidence for efficacy (e.g., supportive for DIP but not TD) and the risks for serious adverse events. If used, anticholinergic medications should be prescribed at the lowest effective dose and for limited periods of time. When discontinued, they should be tapered gradually.

Using wrist-worn accelerometers to identify the impact of medicines with anticholinergic or sedative properties on sedentary time: A 12-month prospective analysis

INTRODUCTION

Studies have shown that use of medicines with sedative or anticholinergic properties is associated with a decline in physical function; however, the effects have not been quantified, and it is not known how and which specific physical movements are affected. This prospective study quantified the impact of a change in sedative or anticholinergic load over time on 24-hour activity composition.

METHODS

This study used data collected from a randomised trial assessing an ongoing pharmacist service in residential aged care. The 24-hour activity composition of sleep, sedentary behaviour, light-intensity physical activity, and moderate to vigorous physical activity was derived from 24-hour accelerometry bands. Mixed effect linear models were used to regress the multivariate outcome of 24-hour activity composition on medication load at baseline and at 12 months. A fixed effect interaction between trial stage and medication load was included to test for differing sedative or anticholinergic load effects at the two trial stages.

RESULTS

Data for 183 and 85 participants were available at baseline and 12 months respectively. There was a statistically significant interaction between medication load and time point on the multivariate outcome of 24-hour activity composition (sedative F = 7.2, p < 0.001 and anticholinergic F = 3.2, p = 0.02). A sedative load increase from 2 to 4 over the 12-month period was associated with an average increase in daily sedentary behaviour by an estimated 24 min.

CONCLUSION

As sedative or anticholinergic load increased, there was an increase in sedentary time. Our findings suggest wearable accelerometry bands are a possible tool for monitoring the effects on physical function of sedative and anticholinergic medicines.

TRIAL REGISTRATION

The ReMInDAR trial was registered on the Australian and New Zealand Trials Registry ACTRN12618000766213.

Polypharmacy and medicine regimens in older adults in residential aged care

OBJECTIVE

To describe medicines regimens used by older people living in residential aged care facilities (RACFs).

MATERIALS AND METHODS

This cross-sectional study presents baseline data from a randomised controlled trial in seventeen Australian RACFs that recruited residents aged 65 years and older at the participating facilities. The main outcome measures were to evaluation of medicines utilisation, including the number of medicines, medicine regimen complexity, potential under-prescribing and high-risk prescribing (prescribing cascades, anticholinergic or sedative medicines or other potentially inappropriate medicines) with data analysed descriptively.

RESULTS

Medicines regimens were analysed for 303 residents (76% female) with a mean age of 85.0 ± 7.5 years, of whom the majority were living with dementia (72%). Residents were prescribed an average of 10.3 ± 4.5 regular medicines daily. Most participants (85%) had highly complex regimens. Most residents (92%) were exposed to polypharmacy (five or more medicines). Nearly all, 302 (98%) residents had at least one marker of potentially suboptimal prescribing. At least one instance of potential under-prescribing was identified in 86% of residents. At least one instance of high-risk prescribing was identified in 81% of residents including 16% of participants with at least one potential prescribing cascade.

CONCLUSION(S)

Potentially suboptimal prescribing affected almost all residents in this study, and most had highly complex medicines regimens. If generalisable, these findings indicate most older people in RACFs may be at risk of medicines-related harm from suboptimal prescribing, in addition to the burden of administration of complex medicines regimens for facility staff and residents.

Anticholinergic burden for prediction of cognitive decline or neuropsychiatric symptoms in older adults with mild cognitive impairment or dementia

BACKGROUND

Medications with anticholinergic properties are commonly prescribed to older adults with a pre-existing diagnosis of dementia or cognitive impairment. The cumulative anticholinergic effect of all the medications a person takes is referred to as the anticholinergic burden because of its potential to cause adverse effects. It is possible that a high anticholinergic burden may be a risk factor for further cognitive decline or neuropsychiatric disturbances in people with dementia. Neuropsychiatric disturbances are the most frequent complication of dementia that require hospitalisation, accounting for almost half of admissions; hence, identification of modifiable prognostic factors for these outcomes is crucial. There are various scales available to measure anticholinergic burden but agreement between them is often poor.

OBJECTIVES

Our primary objective was to assess whether anticholinergic burden, as defined at the level of each individual scale, was a prognostic factor for further cognitive decline or neuropsychiatric disturbances in older adults with pre-existing diagnoses of dementia or cognitive impairment. Our secondary objective was to investigate whether anticholinergic burden was a prognostic factor for other adverse clinical outcomes, including mortality, impaired physical function, and institutionalisation.

SEARCH METHODS

We searched these databases from inception to 29 November 2021: MEDLINE OvidSP, Embase OvidSP, PsycINFO OvidSP, CINAHL EBSCOhost, and ISI Web of Science Core Collection on ISI Web of Science.

SELECTION CRITERIA

We included prospective and retrospective longitudinal cohort and case-control observational studies, with a minimum of one-month follow-up, which examined the association between an anticholinergic burden measurement scale and the above stated adverse clinical outcomes, in older adults with pre-existing diagnoses of dementia or cognitive impairment.   DATA COLLECTION AND ANALYSIS: Two review authors independently assessed studies for inclusion, and undertook data extraction, risk of bias assessment, and GRADE assessment. We summarised risk associations between anticholinergic burden and all clinical outcomes in a narrative fashion. We also evaluated the risk association between anticholinergic burden and mortality using a random-effects meta-analysis.  We established adjusted pooled rates for the anticholinergic cognitive burden (ACB) scale; then, as an exploratory analysis, established pooled rates on the prespecified association across scales.  MAIN RESULTS: We identified 18 studies that met our inclusion criteria (102,684 older adults). Anticholinergic burden was measured using five distinct measurement scales: 12 studies used the ACB scale; 3 studies used the Anticholinergic Risk Scale (ARS); 1 study used the Anticholinergic Drug Scale (ADS); 1 study used the Anticholinergic Effect on Cognition (AEC) Scale; and 2 studies used a list developed by Tune and Egeli.  Risk associations between anticholinergic burden and adverse clinical outcomes were highly heterogenous. Four out of 10 (40%) studies reported a significantly increased risk of greater long-term cognitive decline for participants with an anticholinergic burden compared to participants with no or minimal anticholinergic burden. No studies investigated neuropsychiatric disturbance outcomes. One out of four studies (25%) reported a significant association with reduced physical function for participants with an anticholinergic burden versus participants with no or minimal anticholinergic burden. No study (out of one investigating study) reported a significant association between anticholinergic burden and risk of institutionalisation. Six out of 10 studies (60%) found a significantly increased risk of mortality for those with an anticholinergic burden compared to those with no or minimal anticholinergic burden. Pooled analysis of adjusted mortality hazard ratios (HR) measured anticholinergic burden with the ACB scale, and suggested a significantly increased risk of death for those with a high ACB score relative to those with no or minimal ACB scores (HR 1.153, 95% confidence interval (CI) 1.030 to 1.292; 4 studies, 48,663 participants). An exploratory pooled analysis of adjusted mortality HRs across anticholinergic burden scales also suggested a significantly increased risk of death for those with a high anticholinergic burden (HR 1.102, 95% CI 1.044 to 1.163; 6 studies, 68,381 participants).   Overall GRADE evaluation of results found low- or very low-certainty evidence for all outcomes.  AUTHORS' CONCLUSIONS: There is low-certainty evidence that older adults with dementia or cognitive impairment who have a significant anticholinergic burden may be at increased risk of death. No firm conclusions can be drawn for risk of accelerated cognitive decline, neuropsychiatric disturbances, decline in physical function, or institutionalisation.

Anticholinergic burden for prediction of cognitive decline or neuropsychiatric symptoms in older adults with mild cognitive impairment or dementia

This is a protocol for a Cochrane Review (prognosis). The objectives are as follows:

Primary objective

To assess whether anticholinergic burden, as defined at the level of each individual scale, is a prognostic factor for further cognitive decline or neuropsychiatric disturbances in people with mild cognitive impairment (MCI) or dementia.

Secondary objective

To compare the prognostic validity of different anticholinergic burden scales.

To examine the effect of type of dementia and severity of dementia on the association between anticholinergic burden and rate of cognitive decline or neuropsychiatric disturbances.

To examine the effect of setting (care home versus non‐care home) on the association between anticholinergic burden and rate of cognitive decline or neuropsychiatric disturbances.

To examine whether anticholinergic burden is a prognostic factor for other clinical outcomes in people with MCI or dementia