OAB risk varies in patients taking cholinesterase inhibitors for dementia

Researchers from the University of Houston, Texas, report varying risk of overactive bladder (OAB) in patients taking cholinesterase inhibitors (ChEIs) for dementia and Alzheimer disease; in particular, OAB risk was increased in patients taking donepezil vs rivastigmine.1,2

The investigators reported their findings in the Journal of American Geriatrics Society. The new user retrospective cohort study was conducted using Medicare claims data involving Parts A, B, and D claims dataset from 2013 to 2015. The investigators evaluated a total of 524,975 adults aged 65 years and older with dementia who were using donepezil, galantamine, or rivastigmine. Of the cohort, 80.72% were using donepezil, 16.41% were using rivastigmine, and 2.87% were using galantamine.

Patients who had received a diagnosis of OAB during the baseline period or reported any antimuscarinic or mirabegron (Myrbetriq) use were excluded from the analysis. The study’s primary outcome of interest was OAB diagnosis or prescription of antimuscarinics or mirabegron within 6 months of initiating treatment with a ChEI.

“Multivariable cox proportional hazards regression with propensity scores (PS) as covariates and inverse probability of treatment weighting generated using generalized boosted models was used to assess the risk of OAB among donepezil, galantamine, and rivastigmine users,” the authors wrote in the abstract.

The investigators reported that 5.07% of the cohort received a diagnosis of OAB/antimuscarinic or mirabegron prescription within 6 months of receiving a prescription for a ChEI.

“The Cox regression model with PS as covariate approach found that donepezil use increased the risk of OAB compared to rivastigmine (adjusted HR, 1.13; 95% CI, 1.08-1.28; P <.00001),” the authors wrote.

Senior author Rajender R. Aparasu, PhD, Mustafa and Sanober Lokhandwala Endowed Professor of Pharmacy and chair, Department of Pharmaceutical Health Outcomes and Policy at the University of Houston, commented on the findings in a news release.

“The study found that the risk of overactive bladder varies across individual ChEIs. Using a national cohort of older adults with dementia, we also found that donepezil was associated with a 13% increased risk of OAB compared to rivastigmine, whereas there was no differential risk of OAB with galantamine and rivastigmine,” Aparasu.

Added Aparasu, “The findings suggest the need to understand and manage medication-related morbidity in older adults with dementia.”

References

1. Masurkar PP, Chatterjee S, Sherer JT, Chen H, Johnson ML, Aparasu RR. Risk of overactive bladder associated with cholinesterase inhibitors in dementia. J Am Geriatr Soc. Published online December 2, 2021. doi:10.1111/jgs.17579.

2. Risk of overactive bladder associated with medications for dementia. News release. University of Houston. January 6, 2022. Accessed January 11, 2022. https://www.eurekalert.org/news-releases/939469