Concurrent Anticholinergic and Acetylcholinesterase Inhibitor Drug Use Among Older Adults with Dementia: Commonly Done; Never Advised

Acetylcholine is the main neurotransmitter in the body. It functions to activate muscles and has an important role in attention, learning, memory and motivation. Anticholinergic drugs block the transmission of acetylcholine in the central and peripheral nervous systems, while Acetylcholinesterase inhibitors (AChEIs) increase its availability by blocking the enzyme (acetylcholinesterase) that breaks it down. The concurrent prescribing of anticholinergics and AChEIs is considered to be a “never event”—that is, a medical error that should never occur because the two drugs have opposing mechanisms of action.

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There is strong evidence of a link between anticholinergic drugs and impaired physical functioning, cognitive decline, and even death among older adults, and the American Geriatrics Society flags them for extra caution. Nonetheless, anticholinergic drugs are widely prescribed for older adults. Anticholinergic drug use is even more problematic among older adults with dementia who take acetylcholinesterase inhibitors (AChEIs) to slow the progression of their symptoms.

This study was designed to determine if anticholinergic use among older adults with dementia taking AChEI puts them at higher risk for adverse outcomes and concludes that it does. Older adults with dementia who had concomitant anticholinergic and AChEI use were 18 percent more likely to experience a fall, 16 percent more likely to have a fracture, and 25 percent more likely to have a traumatic brain injury (TBI) than those taking AChEI alone.

Nearly one-third (29 percent) of adults ages 65 years and older in the sample who were taking AChEI drugs for dementia were concurrently prescribed anticholinergic drugs for 30 or more days.

Two-thirds of older adults take at least three prescription medications, often prescribed by more than one clinician. As this study highlights, an essential step towards high quality care should be for health care providers to regularly assess patients and their prescription drug regimens to ensure they remain appropriate (medication reconciliation).

The full report includes a detailed methodological appendix.