Anticholinergic drugs associated with lower cognitive function

Anticholinergic drugs may affect cognition in adults ages 45 years or older, an effect that worsened with age, a study found, but physical activity may mitigate some of the effects.

Researchers used data from The Reasons for Geographic and Racial Differences in Stroke project involving 20,575 adults ages 45 years and older. The anticholinergic cognitive burden scale was used to assess anticholinergic medication use and overall burden. Anticholinergic medications were assigned scores of 1 (possible effect on cognition) or 2 or 3 (definite effect on cognition), and individual medication scores were then summed for a total anticholinergic burden score. Scores of three or more were considered clinically significant. Cognitive data included an overall composite score, memory, and verbal fluency. Physical activity was self-reported at baseline as no activity, one to three sessions a week, and four or more sessions per week. Results of the study were published Feb. 14 by the Journal of the American Geriatrics Society.

Participants with significant anticholinergic burden were estimated to have composite cognitive scores between 0.08 and 0.12 SDs lower than other participants. The study found a significant relationship between anticholinergic burden and composite cognitive scores (P<0.001), with those with higher scores showing more rapid cognitive decline over time. Increasing age was associated with the effect. Fluency and memory composite scores differed across age, but there were no significant three-way interactions between age and anticholinergic burden on cognition over time (memory, P=0.62; fluency, P=0.56). At each age, the gap at baseline between those with and without anticholinergic burden was consistent.

Baseline physical activity level was associated with less cognitive decline over time, and this effect was greater in older cohorts. Compared with those who did not report physical activity, those who engaged in one to three sessions per week had a weaker relationship between anticholinergic burden and cognition, which was not demonstrated for participants who reported four or more weekly sessions.

“Older adults appeared more susceptible to ACHs [anticholinergics], whereas PA [physical activity] emerged as a modifying factor that may protect older adults from the negative cognitive effects of ACHs,” wrote the authors, who suggested that physicians monitor cognition of those with moderate to high anticholinergic burden, consider psychotherapy as adjunct treatment or replacement to antidepressant medications whenever possible, and recommend physical activity to patients who are prescribed anticholinergic drugs.