A significant long-term study discovers that a common class of drugs can impair thinking in older adults and perhaps even increase the risk of death.
The medications are a family of drugs with anticholinergic activity that work by blocking acetylcholine, a nervous system neurotransmitter.
Over-the-counter products containing diphenhydramine, sold under various brand names such as Benadryl®, Dramamine®, Excedrin PM®, Nytol®, Sominex®, Tylenol PM®, and Unisom®, have anticolinergic activity. Other anticholinergic drugs, such as Paxil®, Detrol®, Demerol® and Elavil® are available by prescription.
The two-year study of the impact of these medications on 13,000 men and women aged 65 and older is part of the Medical Research Council (UK) Cognitive Function and Ageing Studies (CFAS), a large UK-based longitudinal multi-center initiative looking at health and cognitive function in older adults.
Results of the study of anticholinergics appear are found in an advance online publication of the Journal of the American Geriatrics Society.
“Our findings make it clear that clinicians need to review the cumulative anticholinergic burden in people presenting with cognitive impairment to determine if the drugs are causing decline in mental status,” said co-author Malaz Boustani, M.D.
“Physicians should review with older patients all the over-the-counter and prescription drugs they are taking to determine exposure,” said Boustani, a geriatrician who sees patients at Wishard Health Services’ Healthy Aging Brain Center in Indianapolis.
The researchers used the Anticholinergic Cognitive Burden Scale developed by Boustani and colleagues at the Regenstrief Institute, Indiana University and in the United Kingdom to evaluate the link between anticholinergic activity and cognitive decline.
Medications with anticholinergic effects are used for many diseases including hypertension and congestive heart failure.
The study found that older age, lower income, and greater number of health conditions increased use of medications with anticholinergic activity. Women were more likely to report taking anticholinergic medications, due to the greater number of health conditions reported by women than by men.
Participants living in institutions were more likely to report taking anticholinergic medications.
“We looked at drugs with either moderate and severe anticholinergic activity. After adjusting for age, sex, baseline mental status, education, income level, number of non-anticholinergic medications and health conditions, we found that taking anticholinergic medications was linked to cognitive impairment and for the first time to death,” said study c0-author Dr. Chris Fox, a psychiatrist.
“We need follow-up to determine the degree to which anticholinergics are being prescribed for diseases with significant risk of death and the impact of that on our findings.”