Co-Prescribing of Anticholinergics and Cholinesterase Inhibitors in Nursing Home Residents: a Potential Deprescribing Cascade

• Background: Polypharmacy may result from inappropriate prescribing of medications to treat adverse drug reactions (ADRs), i.e., “prescribing cascade”. A potentially harmful prescribing cascade affecting those with severe dementia can result when anticholinergics are prescribed to manage side effects of cholinesterase inhibitors (ChEIs). We investigated 1) factors associated with co-prescribing of anticholinergics and ChEIs and 2) whether deprescribing of ChEIs was associated with subsequent discontinuation of anticholinergics - a “deprescribing cascade.” • Methods: We conducted a retrospective analysis of linked Medicare Part A/B/D claims, Master Beneficiary Summary File, Minimum Data Set, Area Health Resource File, and Nursing Home Compare from 2015-16. Subjects were Medicare beneficiaries residing in nursing homes, >65 years old with severe dementia admitted for non-skilled stays, who were prescribed ChEIs. Cross-sectional analysis evaluated factors associated with co-prescribing of anticholinergics with ChEIs. Longitudinal Cox proportional hazards regression examined whether deprescribing ChEIs was associated with subsequent discontinuation of anticholinergics over a one-year period. • Results: We found 15% of our sample experienced co-prescribing of anticholinergics and ChEIs. Several resident and facility-level factors were associated with co-prescribing anticholinergics. Advancing age, minority race or ethnicity, end-stage renal disease, heart failure, and poor appetite were associated with a decreased likelihood of co-prescribing. Female sex, polypharmacy, and non-geriatric prescriber-type were associated with a higher likelihood of co-prescribing. In longitudinal analyses, we observed that deprescribing of ChEIs was associated with a reduced likelihood (HR 0.58 [95% CI, 0.47-0.71]) of discontinuing any anticholinergic medications, however not for antimuscarinic anticholinergics (HR 1.32 [95% CI, 0.83-2.09]), specifically. • Conclusions: Younger, healthier older adults with dementia were more likely to experience co-prescribing anticholinergics and ChEIs. Deprescribing was underutilized, likely due to under recognition of this prescribing cascade. Further research is needed to understand prescribers’ ability to recognize and act on potential prescribing cascades through deprescribing.Doctor of Pharmac