A Common Group of Drugs May Increase the Risk of Dementia

Drugs with an anticholinergic action are commonly prescribed for older patients, even though they are known to sometimes cause confusion and delirium, among other side effects.  The class includes some antidepressants, asthma medications, antihistamines, and drugs used to prevent intestinal cramps; many are available over-the-counter.  A French study, published in the Archives of Internal Medicine, shows that such drugs, taken for long periods by older people, can increase the risk of later dementia.

The study enrolled 4,128 women and 2,784 men, aged 65 or older, living in 3 French cities.  At baseline, 7.5 % of them were taking anticholinergic drugs.  Tests of mental functioning (cognitive performance) and the presence of clinical dementia were carried out after 2 and 4 years. 

After 4 years, there was newly diagnosed dementia in 221 subjects (143 cases of Alzheimer’s disease).  Continuous anticholinergic use was associated with a significantly increased risk of developing dementia; in fact, dementia was 1.65-times more common in users. 

This finding suggests that both physicians and patients should be more careful in using medications with well-established nervous system side effects, even if these are regarded as easily reversible.  It’s easy to slip into chronic use of a drug that may be responsible for long-term effects.  Read the package insert!