Researchers investigate link between polypharmacy and dementia

A recent study found that people with dementia were likely to have been taking more than three drugs during the five years leading up to their diagnosis.

The research, published in Aging and Disease, explored the patterns associated with polypharmacy, the use of multiple medications, and dementia diagnoses to discover if certain medications, or certain combinations of medications, were related to dementia.

A team of researchers, led by Shangming Zhou, PhD, professor of e-Health at the University of Plymouth in the United Kingdom, analyzed the records of 33,000 dementia patients in Wales between 1990 and 2015 using machine learning techniques.

“Our aim in this study was to help doctors find ways to prescribe multiple items of dementia medication safely and without reducing their effectiveness,” said Zhou in a statement. “The use of machine learning has been vital in helping us understand how these patterns develop, and our hope is we can now use this knowledge to treat patients.”

According to the study, the portion of patients taking multiple medications rose from 5.5 percent during the 16 to 20 years prior to their diagnosis, to 82 percent three to five years before diagnosis.

In the years leading up to their diagnosis, two thirds of the patients were found to be taking multiple medications for a combination of respiratory and urinary infections, arthropathies and rheumatism, and cardiovascular disease. Additionally, 22 percent of patients were taking medicine for conditions including infections, arthropathies, rheumatism, cardiometabolic disease, and depression.

The results showed that patterns of polypharmacy varied significantly among patients as they developed dementia. Researchers found that the farther away from diagnosis, the patterns were more distinct, and more patterns were present. However, compared to the patterns seen closer to diagnosis, which were less distinct, the patterns father away from the patients’ diagnosis were less prevalent. The associative diseases tended to cluster, with a larger prevalence in each cluster, closer to the diagnosis, according to the study.

In the conclusion, the study’s authors said these patterns could help clinicians make safer decisions when prescribing medicines for specific conditions and certain combinations of medicines. However, the authors acknowledged that more research is needed to achieve optimal, personalized treatments.

“Given the rise in dementia cases internationally, the need to understand how patterns of polypharmacy evolve before and after a dementia diagnosis are important for devising a safe treatment program for each patient,” said Zhou.