Researchers from Wake Forest University School of Medicine have been busy conducting great research on Alzheimer's and related issues (see my previous blog). This time, they teamed up with researchers from Purdue University to study the combined effect of Alzheimer's medications and drugs for incontinence on 395 nursing home residents in Indiana. Changes in the residents' functioning were compared to changes in functioning among over 3,000 nursing home residents who were taking an Alzheimer's medication but not an incontinence drug.

The results were startling. Those taking both Alzheimer's and incontinence drugs showed a 50% faster decline in functioning compared to those who were taking only an Alzheimer's medication.

There's a good reason why those taking both medications declined more rapidly. Alzheimer's medications such as Aricept, Exelon, and Razadyne increase levels of acetylcholine in the brain; on the other hand, incontinence drugs such as Ditropan actually block acetylcholine. In essence, the drugs work against each other.

If you're scratching your head at this point, you're not alone. I'm trying to figure out why approximately one third of people taking an Alzheimer's medication are also prescribed drugs for urinary incontinence.

Dr. Kaycee M. Sink, the lead author of the study, recommends that when treating people with Alzheimer's, "clinicians should continue to try non-drug management strategies for incontinence before beginning therapy with one of these common drugs." I couldn't agree more.

The good news: This study was conducted from 2003-2004, before newer incontinence medications became available. These newer drugs may have less of an effect on acetylcholine levels than older medications -- but this still needs to be researched.

What are your thoughts on this study? Post a comment to this blog, or start a new discussion in the forum.

For more information:

• What To Ask Your Doctor About Alzheimer's Medications
• Drugs A to Z

Photo of Ditropan © Gold Standard