More Links Between Medications and Cognitive Impairment
Research is showing more connections between some medications and cognitive impairment.
Earlier this year, a study showed a link between proton pump inhibitor use and an increased risk of dementia among seniors. Now, researchers are also recommending that older adults avoid using over-the-counter products such as nighttime cold medicines, sleep aids, night-time pain relievers and antihistamine medications due to their links to cognitive impairment. Using brain imaging techniques, scientists at Indiana University School of Medicine, found lower metabolism and reduced brain sizes in study participants taking drugs known to have an anticholinergic (AC) effect, meaning they block acetylcholine, a chemical involved in the transmission of electrical impulses between nerve cells.
For at least 10 years now, scientists have linked AC drugs to cognitive problems and increased risk of dementia. In fact, a 2013 study found that drugs with a strong anticholinergic effect cause cognitive problems when taken continuously for as few as 60 days. And, drugs with a weaker AC effect could cause impairment within 90 days.
The new paper published in the journal JAMA Neurology
is believed to be the first to study the potential underlying biology using neuroimaging measurements of brain metabolism and atrophy. The current research project involved 451 participants, 60 of whom were taking at least one medication with medium or high AC activity.
To identify possible physical and physiological changes, researchers assessed the results of memory and other cognitive tests, positron emission tests (PET) measuring brain metabolism, and magnetic resonance imaging (MRI) scans for brain structure. The cognitive tests revealed that patients taking anticholinergic drugs performed worse than older adults not taking the drugs on short-term memory and some tests of executive function, which cover a range of activities such as verbal reasoning, planning, and problem solving. And, the brains of those taking AC drugs were, on average, 4% smaller, while the cavities inside the brain were 12% larger.
Anticholinergic drug users also showed lower levels of glucose metabolism, a biomarker for brain activity, in both the overall brain and in the hippocampus, a region of the brain associated with memory and which has been identified as affected early by Alzheimer's disease. People with Alzheimer's disease are known to lack acetylcholine and it is believed that AC drugs may exacerbate or even trigger the condition.
Researchers recommend that use of AC medication among older adults should be discouraged if alternative therapies are available. Fortunately, there are many alternative options for these medications. I recommend that you talk to your doctor, pharmacist, or other healthcare practitioner to discuss the best and safest options for you.
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