Anticholinergic medication use and dementia: latest evidence and clinical implications

Abstract

Use of medications with anticholinergic activity is widespread in older adults. Several studies have highlighted that anticholinergic use may be associated with an increased risk of dementia. The objective of this narrative review is to describe and evaluate studies of anticholinergic medication use and dementia and provide practical suggestions for avoiding use of these medications in older adults. A comprehensive review of the literature, citations from recent reviews and the author's personal files was conducted. Four studies were found that evaluated anticholinergic use and dementia as the primary outcome. Three studies focused on overall anticholinergic medication use and reported a statistically significantly increased risk of Alzheimer's disease or dementia. In one study, dementia risk was primarily found with higher cumulative doses; people using anticholinergic medications at the minimum effective dose recommended for older adults for at least 3 years were at highest risk. In contrast, a study conducted in nursing-home residents with depression did not find that paroxetine [a highly anticholinergic selective serotonin reuptake inhibitor antidepressant, (SSRI)] increased risk for dementia compared with other SSRIs (without anticholinergic activity). Further study is needed to understand the mechanism by which anticholinergic medications may increase risk. In conclusion, there is evidence from three observational studies suggesting that anticholinergic medications may increase dementia risk. Given this potential risk and the myriad of other well-known adverse effects (i.e. constipation, blurred vision, urinary retention, and delirium) associated with anticholinergic medications, it is prudent for prescribers and older adults to minimize use of these medications and consider alternatives when possible.

Distinguishing characteristics of delirium in a skilled nursing facility in Spain: Influence of baseline cognitive status

“…Many were receiving anticholinergic medications or benzodiazepines, recommended to be avoided in patients with delirium and DEM 27,28. This finding is consistent with research in other care settings where delirium symptoms overshadow DEM symptoms when comorbid.…”

Anticholinergic drugs and dementia in older adults

“…Lastly, the authors used a specific replicable method for defining dementia using diagnosis codes from administrative files and they controlled for several important covariates, including indications for anticholinergic drugs. Taken together, these strengths have extended research is this area 567…”

“…It is well established that these drugs can cause temporary short term impairment in cognition, including attention and reaction time 4. Over the past decade, however, mounting evidence suggests that overall use of anticholinergics might be associated with an increased risk of dementia 567…”

Depression in the Context of Medical Disorders: New Pharmacological Pathways Revisited

“…Given this potential risk and the myriad of other well-known adverse effects (i.e. constipation, blurred vision, urinary retention, and delirium) associated with anticholinergic medications, it is prudent to minimize use of these medications and consider alternatives when possible as shown in a recent review [130], However, in this review paroxetine as a highly anticholinergic selective serotonin reuptake inhibitor antidepressant did not increase the risk for dementia when compared with other SSRIs [130]. In the clinical context benzodiazepine use has been associated with an increased risk of dementia, however a recent case control study in 26,459 patients aged ≥65 years with newly diagnosed Alzheimer's disease, long-term use of benzodiazepines was not associated with an increased risk of developing Alzheimer's disease [131].…”