Commonly Used Medications Linked to Dementia

A new study reveals that higher doses or prolonged use of medications with anticholinergic effects significantly increases the risk for developing dementia. Although, this is not the first study to discover such a link, it is the first to suggest that the risk of dementia as a result of taking such medications may not be reversible.

“An anticholinergic agent is a substance that blocks the neurotransmitter acetylcholine in the central and the peripheral nervous system. Anticholinergics inhibit parasympathetic nerve impulses by selectively blocking the binding of the neurotransmitter acetylcholine to its receptor in nerve cells. The nerve fibers of the parasympathetic system are responsible for the involuntary movement of smooth muscles present in the gastrointestinal tract, urinary tract, lungs, etc.”

Anticholinergic agents are used to treat a variety of conditions such as gastrointestinal disorders, respiratory disorders, insomnia, dizziness etc. Some of these commonly used medications include Diphenhydramine (Benadryl, Advil PM etc.), Bupropion (Zyban, Wellbutrin), Dextromethorphan (cough suppressant) and the list goes on. In addition, some of these medications can be acquired without a prescription and can have very strong anticholinergic effects.

Moreover, many older patients, already at higher risk of developing dementia, are frequently using these types of medications. Doctors should be taking a proactive approach and monitoring the use of these drugs, including non-prescription use.

“For instance, the most commonly used medications in the study were tricyclic antidepressants like doxepin (Sinequan), first-generation antihistamines like chlorpheniramine (Chlor-Trimeton), and antimuscarinics for bladder control like oxybutynin (Ditropan). The study estimated that people taking at least 10 mg/day of doxepin, 4 mg/day of chlorpheniramine, or 5 mg/day of oxybutynin for more than three years would be at greater risk for developing dementia.”

Consequently, the study suggests that medical professionals should seek substitutes such as citalopram (Celexa) or fluoxitene (Prozac) for depression or loratadine (Claritin) for allergies or behavioral changes for urinary incontinence. However, if substitutes are not available, the suggestion is to prescribe the lowest dose possible, monitor its effectiveness closely and cease use if there is no real benefit to the patient.

This study differs from other research as it used more rigorous methods, longer follow-up periods and better assessment of medication use by using pharmacy records of both prescription and non-prescription use. It is also the first of its kind to link anticholinergic medication dosages to dementia risk. Results were obtained by tracking nearly 3,500 Group Health seniors participating in the long-running Adult Changes in Thought study (a longitudinal population-based prospective cohort study of brain aging and incident dementia in the Seattle metropolitan area), some of which have also agreed to have their brains autopsied after they die. Stay tuned.

Quick Facts:

Dementia is a general term for a decline in mental ability severe enough to interfere with daily life.

Alzheimer’s is the most common type of dementia.

While symptoms of dementia can vary greatly, at least two of the following core mental functions must be significantly impaired to be considered dementia:

• Memory
• Communication and language
• Ability to focus and pay attention
• Reasoning and judgment
• Visual perception

Many dementias are progressive, meaning symptoms start out slowly and gradually get worse.
Dementia is caused by damage to brain cells, which interferes with the ability of brain cells to communicate with each other.

There is no one test to determine if someone has dementia. Doctors diagnose Alzheimer’s and other types of dementia based on a careful medical history, a physical examination, laboratory tests, and the characteristic changes in thinking, day-to-day function and behavior associated with each type.

Some risk factors for dementia, such as age and genetics, cannot be changed, however some of the most active areas of research in risk reduction and prevention include cardiovascular factors, physical fitness, and diet.

The total number of new cases of dementia each year worldwide is nearly 7.7 million, implying one new case every four seconds. The number of people with dementia is expected to nearly double every 20 years, to 65.7 million in 2030 and 115.4 million in 2050.

The costs are estimated at US$ 604 billion per year at present and are set to increase even more quickly than the prevalence.

Caring for dementia patients is overwhelming for caregivers. The stresses include physical, emotional and economic pressures. Care givers require support from the health, social, financial and legal systems.

People with dementia are frequently denied the basic rights and freedoms available to others. For example, physical and chemical restraints are used extensively in aged-care facilities and acute-care settings.

Improving the awareness and understanding of dementia across all levels of society is needed to decrease discrimination and to improve the quality of life for people with dementia and their caregivers.

More research is needed to develop new and more effective treatments and to better understand the causes of dementia. Research that identifies the modifiable risk factors of dementia is still scarce.

Higher dementia risk linked to more use of common drugs
Anticholinergic
alz.org
World Health Organization