Last Updated: 2008-06-04 11:04:04 -0400 (Reuters Health)

NEW YORK (Reuters Health) - Dual use of anticholinergics for urinary incontinence and cholinesterase inhibitors (CIs) for cognitive impairment in well-functioning elderly patients leads to pharmacological opposition and a more rapid rate of functional decline, researchers report in the May issue of the Journal of the American Geriatrics Society.

"The most important clinical implication" of this study, lead investigator Dr. Kaycee M. Sink told Reuters Health, "is that drugs that cancel each other out should not be used in combination."

Dr. Sink of Wake Forest University, Winston-Salem, North Carolina and colleagues studied data on more than 3500 Medicaid-eligible nursing home residents who were taking cholinesterase inhibitors. Of this group, 367 were concomitantly prescribed the bladder anticholinergics oxybutynin or tolterodine.

The researchers found that in participants who initially had the highest activities of daily living (ADL) function scores and were not taking bladder anticholinergics, ADL function declined by an average of 1.08 points per quarter, while in those who were taking both types of drugs, the decline in ADL score was 1.62 points per quarter -- a significant 50% greater decrease.

In patients who started out with lower scores on ADL function and other measures, there was no excess decline attributable to dual therapy. There also were no between-group differences overall in cognitive function in patients taking or not taking both types of drugs.

Thus, continued, Dr. Sink, "in this particular example, it would be important for physicians and patients to work together to decide which symptom they would rather treat with a medication: the dementia -- Alzheimer's -- or the overactive bladder."

"If it is the dementia," he concluded, "then the overactive bladder symptoms can be managed by non-medication approaches."

J Am Geriatr Soc 2008;56:847-853.