March 9, 2009
Medications commonly prescribed to seniors with a wide range of medical complaints can impair memory, a new study reports. The research is an important reminder that when considering the cause of memory complaints in older people, medications should be carefully considered.
The study, of 500 relatively healthy men aged 65 and older with high blood pressure, looked at a class of medications called anticholinergics, which affect many areas of the body. Anticholinergic drugs are used to treat everything from respiratory complaints like asthma to gastrointestinal problems, hypertension and depression. The findings were published in the Journal of the American Geriatrics Society.
Anticholintergic drugs block the action of a brain chemical called acetylcholine. Among the drugs in this class are the anxiety fighter Xanax (alprazolam), the antidepressants Asendin (amoxapine) and Elavil (amitriptyline), the high blood pressure medicine Lasix (furosemide), the heart medicine Lanoxin (digoxin), the asthma reliever theophylline, and the Parkinson's disease drug Norflex (orphenadrine).
Seniors are particularly susceptible to memory problems from these drugs because they often take multiple medications, both prescription and over-the-counter, that can impair memory. In addition, their bodies may not process drugs as efficiently as a younger person would. In some cases, drug-induced forgetfulness and cloudy thinking can appear similar to the early stages of Alzheimer's disease.
The study found that many older men taking anticholinergic drugs long-term had trouble with daily tasks like shopping and managing finances. The higher the dose of drugs they were taking, the more likely -- and the more severe -- the memory deficits.
"This study extends our previous findings on acute cognitive impairment following recent anticholinergic exposure in older medical inpatients," said study author Dr. Ling Han of the Yale University School of Medicine. "Prescribing for older adults who take multiple prescription and over-the-counter medications requires careful attention to minimize the risk of potential harm from the drugs while maximizing their health benefits."
Other studies have reported similar problems related to anticholinergic drugs. Importantly, despite memory problems, seniors taking these drugs were not at increased risk of Alzheimer's.
It's important to consider drug side effects as a possible cause of memory problems in seniors. In many cases, other medicines can be used, and mental deficits can be reversed.
It might be possible to reduce a patient's use of anticholinergic drugs, especially in cases where a patient might have been over-medicated.
Seniors who are taking these drugs, however, should not stop taking them or reduce the dose on their own, because they may be necessary for the patient's health. However, patients should discuss side effects on memory and other body systems with their doctors.
Han et al. "Cumulative Anticholinergic Exposure Is Associated with Poor Memory and Executive Function in Older Men." Journal of the American Geriatrics Society, 2008; 56 (12): 2203