Common Medications May Harm Memory in Older People

By Kathleen Doheny
HealthDay Reporter
Friday, April 18, 2008; 4:00 AM

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THURSDAY, April 17 (HealthDay News) -- Common medications known as anticholinergic drugs -- used to treat ulcers, stomach cramps, motion sickness, Parkinson's disease and urinary incontinence -- may cause older people to lose their thinking skills more quickly than seniors who don't take the medicines, new research suggests.

"What we found is being on these drugs does worsen your cognitive performance," said Dr. Jack Tsao, an associate professor of neurology at Uniformed Services University in Bethesda, Md., who led the study of the effect of the medications on older adults who were, on average, 75. "In the course of a few years, there is a small slippage. It's a minor effect."

Medications for bladder problems and Parkinson's appear to have the worst effect on memory, he said.

Anticholinergic drugs are a class of medicines that work by blocking the binding of a brain chemical called acetylcholine to its receptor in nerve cells.

"You need acetylcholine for [good] memory," Tsao explained. Drugs used to treat Alzheimer's inhibit the enzyme which breaks down acetylcholine, he said, allowing more of it to be used by the brain.

Tsao was expected to present his research Thursday at the American Academy of Neurology annual meeting, in Chicago.

Tsao's study adds to the body of evidence on the effect of these drugs on memory. "We've known for a long time that in people with Alzheimer's disease, if you put them on drugs with anticholinergic activity, it clearly worsens their memory, without a doubt."

In the new study, he said, they looked at people who had normal cognitive function.

"Taking the drugs doesn't increase your risk of getting Alzheimer's. There was no change in the progression overall to the diagnosis of Alzheimer's," Tsao stressed. However, there was a decline in cognitive abilities.

Tsao's group evaluated the annual changes in thinking ability of 870 Catholic nuns and clergy members who are part of an ongoing study of older people called the Rush Religious Orders Study.

During the eight-year follow-up, 679 participants took at least one medicine that was an anticholinergic. Those who took the drugs had a rate of cognitive function decline that was 1.5 times faster than those not on the drugs.