The results from a recent study published in JAMA Internal Medicine have focused fresh attention on the relationship between anticholinergic medications and dementia. Over the last decade, a growing body of research has suggested that prolonged use of these medications may play a role in a person’s development of dementia.
Anticholinergic drugs act on the nervous system and are used to treat conditions ranging from incontinence to depression. Among other adverse effects, these medications are known to cause confusion and short-term memory loss. Less is known about the potential consequences of their long-term use.
The new study was led by Dr. Carol A. C. Coupland, a professor of medical statistics in primary care at the University of Nottingham. Coupland and her team made use of the QResearch primary care database, which has patient information on hundreds of thousands of individuals in England.
Researchers first identified 58,769 patients with a diagnosis of dementia and 225,574 control patients. Patients from the 2 separate groups were then matched by gender, age, and other characteristics. Next, they reviewed the patients’ prescription histories for 56 different anticholinergic drugs, assessing the patients’ usage during the decade prior to each diagnosis date.
Coupland and her team then grouped the patients based on the total number of doses received. They found that patients 55 years old and older who were prescribed the equivalent of one strong anticholinergic drug daily for 3 years were associated with a nearly 50% increase in odds of developing dementia.
It is important to note the researchers could not evaluate to what extent, if any, anticholinergic medications actually cause dementia. As Coupland told Medscape Medical News:
“All we can say from this data is that there is an association between use of anticholinergic drugs and the development of dementia. We cannot say that this is a causal effect from this observational study.”
Even so, Coupland and her team argue that the findings suggest the need for caution when prescribing these drugs to people who are middle-aged and older.
Talk to Your Physician Before Making Any Changes
For those who take anticholinergic medications, it is best to talk to with your health care provider before making any changes. Coupland said:
“I would suggest that, from what we know so far, clinicians should weigh up the potential benefits and the potential risks of these drugs for their individual patients and consider alternative treatments if possible. For most of these drugs, there are very reasonable alternatives that can be used.”
Dementia refers to a poorly understood set of diseases, and many of the patients it affects have multiple ailments, which makes pointing out specific causes more difficult.
Still, the findings are consistent with prior research, including a study done in the United States. According to Coupland,
“If the association is proven to be a causal effect, we can estimate from our results that anticholinergic drugs could be responsible for about 10% of new cases of dementia."
Dementia is not a normal part of aging, and it affects millions of people worldwide. Could stopping or swapping out one of these drugs keep the brain healthier for longer? It’s too soon to say, but the study had several other notable findings.
Which Kinds of Anticholinergic Drugs Were Associated With an Increased Risk of Dementia?
The results differed depending on the type of anticholinergic drug and the patient’s age at the time of diagnosis. The association was stronger for patients who were diagnosed before age 80, and for those suffering from vascular dementia compared to those diagnosed with Alzheimer’s disease.
The anticholinergic drugs with the strongest dementia risk associations were:
- Antidepressants
- Bladder antimuscarinics
- Antipsychotics
- Antiepileptic drugs
Some of the anticholinergics did not show a significantly increased risk were:
- Antihistamines
- Gastrointestinal antispasmodics
- Antimuscarinic bronchodilators
- Antiarrhythmics
- Skeletal muscle relaxants
Without Conclusive Evidence, Caution Is the Best Route
Dementia is a costly condition. Once people lose significant cognitive and behavioral abilities, they are no longer able to look out for themselves. This puts an enormous financial and emotional strain on both the person affected and their family. Alzheimer’s disease, the most common form of dementia, is the fifth-leading cause of death in America.
While Coupland and her team were unable to make definitive claims about the dementia risks posed by anticholinergic drugs, the results point to a link to which middle-age and older patients should be aware.
People who take a daily dose of anticholinergic drugs — especially antidepressants, bladder antimuscarinics, antipsychotics or antiepileptics — should talk to their doctor about alternative medications.
When medications do not work the way they are supposed to, the consequences can be serious. Learn more about dangerous drugs and what to do if you have been affected.
