Common Allergy Drugs Linked to Memory Problems


PILLS SMALL1If you’re struggling with seasonal allergies, watch out for some common allergy drugs that are linked to problems with memory, language and thinking.

A new study shows that older adults taking widely-used drugs for issues including allergies, sleep, depression and overactive bladder had decreased brain sizes and cognitive impairment, which is trouble learning and remembering things.

The study, published in the journal JAMA Neurology, focused on a common class of drugs known as anticholinergics. Some examples of these medications include brand name and generic versions of Benadryl (diphenhydramine), Demerol (meperidine), Dimetapp (brompheniramine-PPA), Paxil (paroxetine ) and Unisom (doxylamine).

Anticholinergic drugs stop the actions of acetylcholine, a chemical messenger that affects the function of brain areas in processing information. These medications are also commonly used to treat a variety of conditions such as asthma, heart problems, and stomach issues.

A recent related study estimates that 9 million older Americans are prescribed at least one anticholinergic drug that affects learning or thinking.

Study Details

The study looked at 451 total participants with an average age of 73. Of those participants, only 60 were taking anticholinergic drugs. Researchers viewed images of the participants’ brains and noted the physical changes linked to declines in the brain’s function.

They also tested participants’ cognitive abilities such as memory recall, problem-solving skills and verbal reasoning. Participants on anticholinergic drugs scored lower on these tests than participants not on the drug.

The findings might provide a better understanding of how anticholinergic drugs may act upon the brain and increase risk of cognitive impairment, according to the study.

Study Adds to a Growing Body of Research

Murthy-Smitha with fontResults from this study are still somewhat preliminary. “The number of people in the study taking anticholinergic drugs is too small to draw significant conclusions. This study is a starting point. Future, longer-term studies with a larger number of people would be needed,” said Dr. Smitha Murthy, a Ascension Seton Mind Institute expert in psychiatry.

However, this is not the first study to address this issue. Murthy notes that there have been previous studies that have linked anticholinergic drugs to cognitive impairments.

In fact, a 2013 Alzheimer’s & Dementia study found that older adults taking medications with higher levels of anticholinergic activity caused thinking problems when taken continuously for 60 days.

All drugs come with the potential for side effects. In addition to anticholinergic drugs, benzodiazepines can have similar cognitive effects. These drugs are used to treat things like seizures, anxiety or insomnia.

Risk Factor and Effect of Anticholinergic Drugs

Anyone, regardless of age, can potentially experience cognitive issues linked to anticholinergic drugs. However, older adults are at a higher risk.

“For some older adults, their brains’ sizes and activities may have tendencies to decrease as they get older. This leaves them more vulnerable to the anticholinergic medication’s side effects on the brain,” said Murthy.

In addition, people with mild cognitive impairments are at higher risk for Alzheimer’s disease or another form of dementia, according to the Alzheimer’s Association. Those are more serious illnesses that can take away people’s abilities to carry on a conversation or cause confusion about their memories.

Alternatives to Anticholinergic Drugs

“People on anticholinergic medications can talk to their doctors about finding other medications in a different drug class or that have lower anticholinergic levels,” said Murthy.

For example, a physician may suggest loratadine for seasonal allergies, melatonin for sleep problems, or selective serotonin reuptake inhibitors (SSRIs) for depression.

Tips to Help Prevent Cognitive Decline

People worried about cognitive decline can talk to their physicians about their concerns and options for further cognitive testing. However, there are a few simple and easy things people can do to help prevent cognitive problems as they age. These include:

  • Talk to your doctors to understand the side effects of your medications.
  • Eat healthy foods such as fruits, vegetables, whole grains, and lean proteins. A healthy diet with more antioxidants can fight off stress and free radicals that can do damage.
  • Get regular exercise, which helps decrease stress.
  • Be more social. Go hang out with friends and family or join group activities.
  • Make sure to get enough sleep.

For more information about cognitive impairments, visit the Ascension Seton Brain and Spine Center web page.