Use of anticholinergic medications by older adults with dementia.

OBJECTIVES: To compare the prevalence of anticholinergic use in older adults with probable dementia with that of a matched comparison group of older adults who were unlikely to have dementia and to examine the extent to which patients taking donepezil concomitantly use anticholinergic medications.
DESIGN: Retrospective study.
SETTING: Community-based older adults receiving medications through a pharmacy benefit management company. PARTICIPANTS: Eight hundred thirty-six patients aged 65 and older. Patients taking donepezil (n = 418) constituted the treatment group. Patients not taking donepezil (n = 418) constituted the comparison group. Each treatment group member was matched with a comparison group member on the basis of age, sex, and number of drugs taken for chronic conditions. MEASUREMENTS: The prevalence of anticholinergic use was compared in the treatment and comparison groups over a 3- to 12-month follow-up period using pharmacy claims data. The proportion of follow-up period days that treatment group members concomitantly used donepezil and anticholinergics was also examined.
RESULTS: Older adults with probable dementia were more likely to use anticholinergics than matched comparison group patients (33.0% vs 23.4%; P =.001). Of treatment group members receiving anticholinergics, 26.1% used multiple anticholinergic medications. Treatment group members who received anticholinergics used those drugs concomitantly with donepezil on a mean of 28.4% of follow-up period days.
CONCLUSIONS: Community-based, commercially insured, older adults with probable dementia are more likely to take anticholinergics than matched controls. Patients taking donepezil frequently use an anticholinergic medication concomitantly. This study suggests that prescribing for older adults with dementia could be improved, especially if cognitive enhancing agents are being considered.