Alzheimer's, Dementia & Mental Health
Commonly Used Medications May Produce Cognitive
Impairment in Senior Citizens
Study of older adults in progress to see if the long
term use of these drugs is linked to irreversible cognitive impairment
such as Alzheimer disease
June 1, 2009 - Many drugs commonly prescribed to
older adults for a variety of medical conditions, including allergies,
hypertension, asthma, and cardiovascular disease, appear to negatively
affect the aging brain, causing immediate, but possibly reversible
cognitive impairment, including delirium, in senior citizens. Some are
concerned it may lead to more permanent damage and even Alzheimer
disease.
The clinical review, partially funded by the
National Institute on Aging, is now available online in the Journal
of Clinical Interventions in Aging, a peer reviewed, open access
publication.
Drugs, such as diphenhydramine, which have an
anticholinergic effect, are important medical therapies available by
prescription and also are sold over the counter under various brand
names such as Benadryl, Dramamine, Excederin PM, Nytol, Sominex, Tylenol
PM, and Unisom. Older adults most commonly use drugs with
anticholinergic effects as sleep aids.
Note: The anticholinergic effect is the blocking
nerve of impulses that are part of the stress response.
While it is known that these medications do have an
effect on the brain, and in the case of sleeping pills, are prescribed
to act on the brain, the study authors suggest the amount of cognitive
impairment caused by the drugs in older adults is not well recognized.
"The public, physicians, and even the Food and Drug
Administration, need to be made aware of the role of these common
medications, and others with anticholinergic effects, in causing
cognitive impairment, says senior study author Malaz Boustani, M.D.,
Indiana University School of Medicine associate professor of medicine,
Regenstrief Institute investigator, and research scientist with the IU
Center for Aging Research.
Patients should write down and tell their doctor
which over-the-counter drugs they are taking.
Doctors, who often think of these medications
simply as antihistamines, antidepressants, antihypertensives, sleep aids
or even itching remedies, need to recognize their systemic
anticholinergic properties and the fact that they appear to impact brain
health negatively. Doing so, and prescribing alternative medications,
should improve both the health and quality of life of older adults."
Dr. Boustani and colleagues conducted a systematic
evidence-based analysis of 27 peer reviewed studies of the relationship
of anticholinergic effect and brain function as well as investigating
anecdotal information. They found a strong link between anticholinergic
effect and cognitive impairment in older adults.
"One of the goals of our work is to encourage the
Food and Drug Administration to expand its safety evaluation process
from looking only at the heart, kidney and liver effects of these drugs
to include effects of a drug on the most precious organ in human beings,
our brain," Dr. Boustani said.
"Many medications used for several common disease
states have anticholinergic effects that are often unrecognized by
prescribers" said Wishard Health Services pharmacist, Noll Campbell,
Pharm.D., first author of the study, noting that these drugs are among
the most frequently purchased over the counter products.
"In fact, 50 percent of the older adult population
use a medication with some degree of anticholinergic effect each day."
Dr. Boustani said "Our main message is that older
adults and their physicians should have conversations about the benefits
and harms of these drugs in relation to brain health. As the number of
older adults suffering from both cognitive impairment and multiple
chronic conditions increases, it is very important to recognize the
negative impact of certain medications on the aging brain."
The brain pharmacoepidemiology group of the IU
Center for Aging Research currently is conducting a study of 4,000 older
adults to determine if the long term use of medications with
anticholinergic effects is linked to the irreversible development of
cognitive impairment such as Alzheimer disease.
Background Information
Authors of the JCIA study are Noll Campbell,
Pharm.D., Wishard Health Services; Malaz Boustani, M.D., MPH; Tony
Limbil, M.D., MPH, of University of Illinois; Carol Ott, Pharm.D. of
Wishard and Purdue University; Chris Fox, MRCPsych and Ian Maidment,
B.Pharm., of Kent Institute of Medicine and Health Sciences University
of Kent and Medway NHS Trust, United Kingdom; Cathy C. Schubert, M.D. of
the IU School of Medicine; Stephanie Munger, B.S., of Regenstrief and
IUCAR; Donna Fick, R.N., Ph.D., of Pennsylvania State University; David
Miller, M.D., of the IU School of Medicine and Rajesh Gulati, M.D., of
IU Medical Group Primary Care.
The study was funded by the John A. Hartford
Foundation, the Atlantic Philanthropies, the Starr Foundation, and the
National Institute on Aging.
