Sex differences in the prevalent use of oral formulations of cholinesterase inhibitors in older adults with dementia

Background — Cholinesterase inhibitors (ChEIs) are one of only two drug therapies available to manage cognitive decline in dementia. Given sex-specific differences in medication access and effects, it is important to understand how ChEIs are used by women and men.

Objective — The objective of this study was to provide contemporary sex-stratified evidence on patterns of ChEI use by community-dwelling older adults with dementia to inform opportunities to optimize drug prescribing.

Methods — We conducted a population-based cross-sectional study examining ChEI use in older adults with dementia in Ontario, Canada. We identified all community-dwelling individuals aged 66 years and older with a pre-existing diagnosis of dementia as of 1 April, 2016. We examined the prevalence of ChEI use among women and men separately, and explored the association between ChEI use and age, sex, income status, geographic location of residence, use of palliative care services, comorbidity, and polypharmacy. Concurrent use of drugs known to impair cognition (including antipsychotics, benzodiazepines, and medications with strong anticholinergic properties) was separately assessed among women and men using multivariable analyses and prevalence risk ratios.

Results — Of 74,799 women and 52,231 men living with dementia in the community, nearly 30% currently were using a ChEI (29.3% women, 28.6% men). Close to 70% of users were receiving the target therapeutic dose. Compared to men, women were less often taking the target therapeutic dose (67.8% women vs. 71.6% men, p < 0.001). Over 20% of users also were using drugs known to impair cognition, while being treated for cognitive decline using ChEIs. Compared to men, women were more often concurrently using drugs known to impair cognition (23.9% women vs. 21.8% men, p < 0.001).

Conclusions — This is one of the first studies of ChEI use to account for important sex differences. The results remind clinicians and researchers that patterns of ChEI therapy use differ by sex, as women were less likely to receive target therapeutic doses and more vulnerable to potentially problematic polypharmacy than men.