Rationale and Comments

Anticholinergics (e.g., overactive bladder medications, first-generation antihistamines) competitively inhibit binding of the neurotransmitter acetylcholine, thus reducing the effects of acetylcholine. Cholinesterase inhibitors, used in the treatment of dementia, act by blocking the enzyme acetylcholinesterase, thereby inhibiting acetylcholine degradation. Therefore, pharmacologic actions of anticholinergics and cholinesterase inhibitors oppose each other. Concomitant use of anticholinergics with cholinesterase inhibitors reduces the effectiveness of antidementia drugs, the benefits of which are modest at best; concomitant use increases the risk of adverse effects of anticholinergics and may also increase the rate of functional and cognitive decline. Medications with anticholinergic properties are commonly prescribed to treat comorbidities associated with dementia and sometimes the adverse effects of cholinesterase inhibitors. Patients with dementia are sensitive to cognitive impairment induced by medications with anticholinergic properties. In general, it has been recognized that anticholinergics adversely affect cognition in older patients and even more so with concomitant dementia diagnosis.

Sponsoring Organizations

• American Society of Consultant Pharmacists

Sources

• Cohort studies

Disciplines

• Geriatric Medicine
• Neurologic

References

• Valladales-Restrepo LF, Duran-Lengua M, et al. Potentially inappropriate prescriptions of anticholinergics drugs in Alzheimer’s disease patients. Geriatrics Gerontol Int. 2019;19(9):913-917.
  
• Ah Y-M, Suh Y, et al. Effect of anticholinergic burden on treatment modification, delirium and mortality in newly diagnosed dementia patients starting a cholinesterase inhibitor: a population-based study. Basic Clin Pharmacol Toxicol. 2019;124(6):741-748.
  
• Gill S, Mamdani M, et al. A prescribing cascade involving cholinesterase inhibitors and anticholinergic drugs. Arch Intern Med. 2005;165:808-813.
  
• Boudreau DM, Yu O, et al. Concomitant use of cholinesterase inhibitors and anticholinergics: prevalence and outcomes. J Am Geriatr Soc. 2011;59:2069-2076.
  
• Beier MT. Cholinesterase inhibitors and anticholinergic drugs: is the pharmacologic antagonism myth or reality? J Am Med Dir Assoc. 2005;6(6):413-414.
  
• Sink KM, Thomas J, et al. Dual use of bladder anticholinergics and cholinesterase inhibitors: long-term functional and cognitive outcomes. J Am Geriatr Soc. 2008;56:847-853.
  
• Narayan SW, Pearson S, et al. Anticholinergic medicines use among older adults before and after initiating dementia medicines. Br J Clin Pharmacol. 2019;85(9):1957-1963.
  
• Knight R, Khondoker M, et al. A systematic review and meta-analysis of the effectiveness of acetylcholinesterase inhibitors and memantine in treating the cognitive symptoms of dementia. Dement Geriatr Cogn Disord. 2018;45(3-4):131-151.
  
• 2019 American Geriatrics Society Beers Criteria® Update Expert Panel. American Geriatrics Society 2019 updated AGS Beers Criteria for potentially inappropriate medication use in older adults. J Am Geriatr Soc. 2019;67(4):674-694.