A new study in the University of Washington provides strong evidence that certain popular drugs may increase the risk of dementia in older adults. The drugs share some common mechanisms within key areas of the brain but are used primarily as ingredients in over-the-counter sleep, cough, cold, and allergy medicines as well as in the treatment of an overactive bladder and depression.
Drugs And Dementia
The most commonly used drug linked to dementia is diphenhydramine, which is used in many popular products such as Benadryl, Nytol Sominex, Theraflu, Triaminic Allergy, etc. It is also implicated in drugs containing chlorpheniramine (Aller-Chlor); oxybutynin (Ditropan) and tolterodine (Detrol) for overactive bladder; and tricyclic antidepressants, such as doxepin or amitriptyline.1
Background Data
Acetylcholine is a critical brain chemical involved in the transmission of nerve impulse and is especially important for proper memory and cognitive function. For example, Alzheimer’s disease is associated with a severe reduction in acetylcholine levels due
Given the link between low acetylcholine levels and poor brain function, including dementia, previous studies have linked drugs to reduced acetylcholine activity as well as mild cognitive impairment. These drugs include the ones mentioned earlier.
While discontinuation of the drugs is thought to reverse the mental deficit, there is evidence that anticholinergic drugs may produce permanent changes leading to irreversible dementia.
These drugs are known to cause short-term drowsiness or confusion, which is included in the prescribing information, but the long-term effects these drugs have on mental function are generally not known by physicians or the people taking them.3 4 5
Other
New Data
To evaluate whether cumulative anticholinergic use is associated with a higher risk of incident dementia, researchers examined medical records from 3,434 participants 65 years or older with no dementia at study entry. Initial recruitment occurred from 1994 through 1996 and from 2000 through 2003 and data through September 30, 2012 were also included in these analyses.6
Exposure to anticholinergic drugs was determined from computerized pharmacy records. Cumulative exposure was updated as participants were followed up over a 10-year period. About 20% of the population was found to be using anticholinergic drugs.
During
Even at low dosage or recommended levels, chronic use of these drugs should be avoided.
Based upon these results, the authors of the study propose efforts to increase awareness among health care professionals and older adults about the risk of the use of these drugs over time.
Bottom Line
The results from this study highlight the importance of avoiding long-term use of such drugs, including diphenhydramine and over-the-counter sleeping pills. What this research further establishes is that the human brain can be adversely affected by minor pharmacological agents, highlighting the importance of using natural approaches that not only address the key issue (e.g., insomnia, allergies, etc.) but also have a positive effect on brain function.
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