A study published in Journal of the American Geriatrics Society suggested that the use of certain medications in elderly populations may be associated with cognitive decline. The study examined the effects of exposure to anticholinergic medications, a type of drug used to treat a variety of disorders that include respiratory and gastrointestinal problems, on 544 relatively healthy men aged 65 years or older with high blood pressure.

Older people often take several drugs to treat multiple health conditions. As some of these drugs also have properties that affect neurotransmitters in the brain that are important to overall brain function, the researchers examined the total effects of all medications taken by the patients, both prescription and over-the-counter, that were believed to affect the function of a particular neurotransmitter, acetylcholine.

The outcomes were measured using the Hopkins Verbal Recall Test (HVRT) for short-term memory and the instrumental activity of daily living (IADL) scale for executive function. Anticholinergic medication use was ascertained using participants' primary care visit records.

The findings show that chronic use of medications with anticholinergic properties may have detrimental effects on memory and the ability to perform daily living tasks, such as shopping and managing finances. Participants showed deficits in both memory and daily function when they took these medications over the course of a year. The degree of memory difficulty and impairment in daily living tasks also increased proportionally to the total amount of drug exposure, based on a rating scale the authors developed to assess anticholinergicity of the drugs.

On average, a 1-unit increase in the total anticholinergic burden per 3 months was associated with a 0.32-point (95% confidence interval (CI)= 0.05-0.58) and 0.10-point (95% CI=0.04-0.17) decrease in the HVRT and IADLs, respectively, independent of other potential risk factors for cognitive impairment, including age, education, cognitive and physical function, comorbidities, and severity of hypertension. The association was attenuated but remained statistically significant with memory and executive function after further adjustment for concomitant non-anticholinergic medications.

According to study co-author Dr. Ling Han of the Yale University Department of Internal Medicine, elderly patients may be more vulnerable to these types of medications due to neurological and pharmacokinetical changes related to aging.

"This study extends our previous findings on acute cognitive impairment following recent anticholinergic exposure in older medical inpatients," says Han. "Prescribing for older adults who take multiple prescription and over-the-counter medications requires careful attention to minimize the risk of potential harms of the drugs while maximizing their health benefits."