A new study by the University Of Houston College Of Pharmacy has evaluated the risk of overactive bladder (OAB) as a side effect of cholinesterase inhibitor (ChEI) drugs taken for dementia and Alzheimer's disease.

The research has been published in the American Geriatrics Society Journal. Dementia is a group of symptoms associated with a decline in memory, reasoning, or other thinking skills. Alzheimer's disease is the most common cause of dementia, accounting for 60 per cent-80 per cent of cases. ChEI drugs, including donepezil, galantamine, and rivastigmine, increase communication between nerve cells to enhance cognition.

"The study found that the risk of overactive bladder varies across individual ChEIs," reported Rajender R. Aparasu, Mustafa, and Sanober Lokhandwala Endowed Professor of Pharmacy and chair, Department of Pharmaceutical Health Outcomes and Policy.

"Using a national cohort of older adults with dementia, we also found that donepezil was associated with a 13 per cent increased risk of OAB compared to rivastigmine, whereas there was no differential risk of OAB with galantamine and rivastigmine," they added.

Using Medicare data, the study examined 524,975 adults (aged 65 and older) with dementia who were users of ChEIs (donepezil 80.72 per cent, rivastigmine 16.41 per cent, galantamine 2.87 per cent). The primary outcome of interest was OAB diagnosis or prescription of antimuscarinics, drugs that helped correct overactive bladder, within six months of ChEI initiation.

While some studies have been conducted to evaluate the effects of all ChEIs and antimuscarinic use, few studies have been conducted regarding the effects of individual ChEIs on the risk of OAB. Previous studies have found that the use of ChEIs is associated with an increased risk of receiving an antimuscarinic drug. This study opens a new door.

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