May 27, 2008
So-called "anticholinergic" medicines for motion sickness, urinary incontinence and other conditions may cause older people to experience greater decline in their thinking skills than people not taking the drugs. The findings highlight the important of discussing medication use with your doctor, as a wide variety of drugs may cause problems with thinking and memory. In many cases, the dosage can be adjusted, or a different drug can be substituted, to correct the problem.
The findings, presented at the American Academy of Neurology 60th Anniversary Annual Meeting in Chicago, were part of the large and ongoing Religious Orders Study. Researchers at Rush University in Chicago looked at the effects these medications had on the annual change in thinking abilities of 870 older Catholic nuns and clergy members. The study participants were, on average, 75 years old.
At the start of the study, none were suffering from Alzheimer's disease or other serious forms of memory loss. All of the participants underwent annual tests of memory and thinking skills. They also reported what medications they were taking over eight years. During the study, which lasted eight years, 679 of the 870 participants, or nearly 80 percent, reported taking at least one medication with anticholinergic properties.
The study found men and women who took anticholinergic drugs saw their rate of cognitive function decline one-and-a-half times faster than others who did not take the drugs. Anticholineric drugs have been implicated in temporary reductions in cognitive function in the elderly in previous studies. However, like many correlational studies, the present one does not determine whether the effects on cognition were the result of the medication or were due to unknown differences among the study participants.
The study authors, however, conclude, "Our findings point to anticholinergic drugs having an adverse impact on cognitive performance in otherwise normal, older people," said study author Jack Tsao, M.D., associate professor of neurology at Uniformed Services University in Bethesda, Md. "Doctors may need to take this into account before prescribing these commonly used drugs."
Dr. Tsao says more research is needed to determine the mechanism behind the rapid memory loss apparently associated with anticholinergic drugs. In addition, it is important to clarify which drugs, in particular, may be more likely to impair thinking and memory.
An Array of Medications
Anticholinergic drugs affect the peripheral nervous system, which spans throughout the body, from the lungs and eyes to the urinary tract and GI tract. Their uses are many and varied. They include drugs to treat overactive bladder and asthma, muscle relaxants, medications for Parkinson's disease and ulcers, drugs for vision disorders, and more.
The findings underline the importance of considering many factors when memory loss becomes a problem. Memory, concentration, focus and thinking may all be affected by the side effects of medications. The effects may be felt in healthy individuals as well as those with Alzheimer's disease.
For this reason, it's important to discuss with your physician any medications you or a loved one with Alzheimer's disease may be taking. These include prescription drugs, those sold over-the-counter at pharmacies, and herbal and dietary supplements.
If personality or thinking abilities are impaired, it is important to consider medications as a possible cause, both in healthy individuals and those with Alzheimer's disease. Your doctor may be able to adjust the dosage, or give you a substitute medicine, so that side effects are not as severe.
Source: Presented at the American Academy of Neurology 60th Anniversary Annual Meeting in Chicago, April 12 to 19, 2008.