Older nursing home residents who took medications for dementia and incontinence at the same time had a 50 percent faster decline in function than those who were being treated only for dementia, according to a study from researchers at Wake Forest University School of Medicine and colleagues.
"It is likely that the oppositional effects of the drugs contributed to the accelerated decline," said Kaycee M. Sink, M.D., M.A.S., lead author. "Over a year's time, the decline we observed would represent a resident going from requiring only limited assistance in an activity to being completely dependent, or from requiring only supervision to requiring extensive assistance in an activity."
The combination of drugs affected older adults who started out with higher levels of function in activities of daily living such as dressing, personal hygiene, toileting, transferring, bed mobility, eating and being able to get around the unit. The results were published online by the Journal of the American Geriatrics Society and will appear in a future print issue.
The two most common medical conditions among nursing home residents are dementia and urinary incontinence and they often coexist. The study involved 395 nursing home residents in Indiana who were taking medications for both conditions and 3,141 who were taking only a dementia medication.
Residents included in the analysis were age 65 and older and had had at least two consecutive prescriptions for cholinesterase inhibitors, a family of drugs used to treat dementia. Examples include donepezil (Aricept®), galantamine (Razadyne®), rivastigmine (Exelon®), and tacrine (Cognex®). These drugs are designed to increase levels of acetylcholine, a chemical that enhances communication between nerve cells in the brain.
About 10 percent of the residents were also taking either oxybutynin or tolterodine, the two most commonly prescribed drugs for urinary incontinence. These drugs are known as anticholinergic agents and are designed to block acetylcholine.
"The two drugs are pharmacological opposites, which led us to hypothesize that the simultaneous treatment of dementia and incontinence could lead to reduced effectiveness of one or both drugs," said Sink, an assistant professor of internal medicine-gerontology.