- The use of some common drugs has
been associated with decreased brain size.
- Anticholinergics that are responsible for
transferring electrical impulses between nerves have been found to lower
metabolism and increase risk for Alzheimer's and dementia.
- The study participants showed lower brain
volume with larger cavities inside the brain.
Over the counter
drugs like the ones for hay fever and asthma could increase the risk for
dementia when consumed for a prolonged period, urging senior adults to
reconsider their drug choices.
A new study by Dr Shannon L. Risacher and colleagues focuses on the effects of anticholinergic drugs
on brain volume and brain activity, a first of its kind study where the effects of commonly used drugs on brain activity are studied.
‘Drugs used for hay fever medication, asthma and sleeping pills can lead to reduced brain size and cognition in senior adults.’
"These findings provide us with a much better understanding of how this class of drugs may act upon the brain in ways that might raise the risk of cognitive impairment and dementia
." said Dr Shannon Risacher, who is an assistant professor of radiology and imaging sciences and first author of the paper.
assessed the association between the use of anticholinergic drugs and glucose
metabolism, brain atrophy and cognition among cognitively normal adults. Data
for the study was collected from the Alzheimer's Disease Neuroimaging
Initiative (ADNI) and The Indiana Memory and Aging Study (IMAS).
About 409 participants
were included in the ADNI study and after the first baseline study, the study
participants were checked after 3,6 and 12 months, after than annually. Among them, 52 participants took anticholinergic drugs while 350 participants
did not take anticholinergic drugs.
In the IMAS
study, 49 study participants were included in the study with 8 participants
taking anticholinergic drugs while 41 participants didn't. After the initial
baseline study, the participants were checked every 18 months.
The duration of the study was as long as
4 years for many participants. Participants who took anticholinergic drugs were
found to have lower:
of the temporal lobe cortical
and greater lateral ventricle volumes
The study results found that there was a sharp clinical decline in the size of the brain with increased brain atrophy and dysfunction. The research provides evidence that the use of cholinergic drugs can lead to cognitive decline, especially in older adults and so alternative drugs should be used for treatment. There was a statistically significant increase in risk for cognitive decline by 54% for older adults who took anticholinergic drugs and 63% increased risk of Alzheimer's.
Though there have been studies that were conducted earlier to analyze the association between prolonged drug usage and cognitive decline
, this is the first study that looks at the biological pathways that lead to the decline, using neuro-imaging techniques.
further states that "These findings might give us clues to the biological basis
for the cognitive problems associated with anticholinergic drugs, but
additional studies are needed if we are to truly understand the mechanisms
drugs act on muscles around the bronchi. When there is lung irritation, the
muscles around the bronchi tighten resulting in narrow bronchi. Anticholinergic
drugs act on these muscles and prevent narrowing of the bronchi.
This study by Dr Risacher has found that over-the-counter anticholinergic drugs are used for hay fever, asthma and even sleeping pills. Older adults who have been using drugs like Benadryl
Nytol and Piriton
for 3 years have more than 60% chance of developing Alzheimer's.
behind the increased risk for Alzheimer's is believed to be due to these drugs
blocking the release of acetylcholine which is necessary for the transmission
of electrical signals between nerve cells. In Alzheimer's, there is lowered
level of acetylcholine, therefore, these drugs may lead to
aggravation of the condition or could trigger the condition in the elderly.
that Increase Risk for Dementia
who require these drugs for treatment should be monitored closely. The lowest
dosage that provides the required relief should be administered for the
patients and the progress of the treatment closely recorded. Alternate drugs
that do not produce cognitive decline should then be used to protect the
cognitive abilities of the patient.
Since many of
these drugs are available over the counter, it is difficult for doctors to
monitor their usage by older adults. However, the conclusive evidence provided
by this research warrants better awareness among senior citizens to prevent
Here are some
tips for the elderly to follow as a result of this research:
with a doctor about medications for hay fever, asthma or any ailment instead of self-medicating.
- Do not
stop any medication till the doctor is consulted.
- Ask for
- Shannon L. Risacher, PhD1,2; Brenna C. McDonald, PsyD, MBA1,2,3; Eileen F. Tallman, BS1,2; and colleagues "Association Between Anticholinergic Medication Use and Cognition, Brain Metabolism, and Brain Atrophy in Cognitively Normal Older Adults" JAMA Neurol. Published online April 18, 2016.