Among nursing home residents the 2 most common medical conditions are dementia and urinary incontinence; often they coexist. The problem is that the drugs used to treat each condition are pharmacological opposites, which can reduce the effectiveness of one or both drugs.

Kaycee M. Sink, MD, MAS, Wake Forest University School of Medicine, and colleagues, studied 3,141 Indiana nursing home residents who were taking dementia medication, which included 395 residents who were taking both dementia and urinary incontinence medication. Subjects were 65 years or older.

Subjects of the study had at least 2 consecutive prescriptions for cholinesterase inhibitors–i.e. Aricept®, Razadyne®, Exelon®, Cognex®–used to treat dementia. Of the subjects in the study approximately 33% of the people with dementia also take a drug for incontinence. Approximately, 10% of the residents also took one of the 2 most commonly prescribed urinary incontinence drugs–oxybutynin or tolterodine.

Researchers found that nursing home residents who took medications for dementia and incontinence at the same time had a 50% faster decline in function than those who were being treated only for dementia.

Also noted by researchers is that their study was conducted between 2003 and 2004, which is before newer incontinence medications were introduced that may have less of an effect on the brain.