Anticholinergic Drug Burden in Persons With Dementia Taking a Cholinesterase Inhibitor: The Effect of Multiple Physicians

Christina E. Reppas-Rindlisbacher, BSc; Hadas D. Fischer, MD, MSc; Kinwah Fung, MSc; Sudeep S. Gill, MD, MSc; Dallas Seitz, MD, PhD; Cara Tannenbaum, MD, MSc; Peter C. Austin, PhD; Paula A. Rochon, MD, MPH

Disclosures

J Am Geriatr Soc. 2016;64(3):492-500. 

In This Article

Abstract and Introduction

Abstract

Objectives To explore the association between the number of physicians providing care and anticholinergic drug burden in older persons newly initiated on cholinesterase inhibitor therapy for the management of dementia.

Design Population-based cross-sectional study.

Setting Community and long-term care, Ontario, Canada.

Participants Community-dwelling (n = 79,067, mean age 81.0, 60.8% female) and long-term care residing (n = 12,113, mean age 84.3, 67.2% female) older adults (≥66) newly dispensed cholinesterase inhibitor drug therapy.

Measurements Anticholinergic drug burden in the prior year measured using the Anticholinergic Risk Scale.

Results Community-dwelling participants had seen an average of eight different physicians in the prior year. The odds of high anticholinergic drug burden (Anticholinergic Risk Scale score ≥ 2) were 24% higher for every five additional physicians providing care to individuals in the prior year (adjusted odds ratio = 1.24, 95% confidence interval = 1.21–1.26). Female sex, low-income status, previous hospitalization, and higher comorbidity score were also associated with high anticholinergic drug burden. Long-term care facility residents had seen an average of 10 different physicians in the prior year. After a sensitivity analysis, the association between high anticholinergic burden and number of physicians was no longer statistically significant in the long-term care group.

Conclusion In older adults newly started on cholinesterase inhibitor drug therapy, greater number of physicians providing care was associated with higher anticholinergic drug burden scores. Given the potential risks of anticholinergic drug use, improved communication among physicians and an anticholinergic medication review before prescribing a new drug are important strategies to improve prescribing quality.

Introduction

Medications used to manage a variety of clinical conditions (e.g., urinary incontinence, depression, Parkinson's disease) have anticholinergic effects that can cause adverse events, including cognitive decline.[1–4] The use of drug therapies that might worsen cognitive status is especially troubling in older adults with preexisting cognitive deficits and age-related changes in pharmacodynamics that lead to heightened sensitivity to central anticholinergic adverse effects.[5,6]

Although prescribing anticholinergic drugs to persons with dementia is generally considered inappropriate,[7] it often happens in clinical practice.[8,9] Anticholinergic drug therapy combined with cholinesterase inhibitor drug therapy[10] is particularly troubling. In this case, the directly opposing action of the anticholinergic drugs may reduce or eliminate the cognitive benefits gained from cholinesterase inhibitors.[11]

Efforts to identify drug therapies that are potentially inappropriate have largely targeted individual drug therapies[12,13] rather than considering the cumulative burden of different drugs with similar mechanisms of action. It is important to consider how overall drug burden may contribute to adverse events. Anticholinergic drug therapies with varying degrees of anticholinergic activity illustrate this situation. Although the anticholinergic effects of the individual drug therapies are important, estimating the cumulative anticholinergic burden from all prescribed drug therapies may more accurately predict the risk of adverse events.

Having multiple prescribers has been linked to polypharmacy, potential drug interactions, and adverse events.[14–16] Older adults with dementia and multiple comorbid conditions are particularly vulnerable to inadvertent prescription of inappropriate drug combinations because they often receive care from multiple physicians. Poor communication among physicians caring for the same individual may lead to prescription of inappropriate drug combinations from different sources. Through the Choosing Wisely campaign, the American Geriatrics Society suggests a medication review before starting any new drug therapy to improve the quality of prescribing in vulnerable elderly adults.[17]

Given the potential risks of anticholinergic drug use in older adults, a better understanding of the causes of frequent prescription is needed. The objective of this study was to examine the relationship between the number of physicians providing care and anticholinergic drug burden in older adults newly initiated on cholinesterase inhibitor therapy for dementia. It was hypothesized that having more physicians involved in care would be associated with greater risk of high anticholinergic drug burden.

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