A new study from researchers at the University of Cambridge and the University of Exeter found that commonly used drugs, including antibiotics, vaccines, and anti-inflammatory medications, may reduce the risk of developing dementia. The research, published in Alzheimer’s & Dementia: Translational Research & Clinical Interventions, analyzed the health records of more 130 million people from 14 large-scale studies to identify potential drug repurposing candidates that could help reduce the incidence of dementia.
“We urgently need new treatments to slow the progress of dementia, if not to prevent it,” said co-first author Ben Underwood, MD, PhD, and associate professor in the department of psychiatry at Cambridge. “If we can find drugs that are already licensed for other conditions, then we can get them into trials and—crucially—may be able to make them available to patients much, much faster than we could do for an entirely new drug.”
Despite extensive research, the development of new drugs for treating dementia is challenging. Currently, most treatments only address symptoms, with limited success. Two recent approvals by the FDA, lecanemab and donanemab—targets amyloid plaques in the brain—have shown promise in slowing Alzheimer’s progression; however, the National Institute for Health and Care Excellence (NICE) has not approved them for use in England’s National Health Service (NHS) due to their finding of insufficient benefits. This has led some to conduct research focused on drugs that are already approved and could be repurposed to treat dementia more quickly and cost-effectively, with less risk for patients.
An unexpected finding of the drug repurposing study was the association between antibiotics, vaccines, and antivirals, all of which are linked to a reduced risk of dementia. This finding indicates that infections may play a role in triggering the disease, the researchers noted. Further, anti-inflammatory medications, such as ibuprofen, were associated with a lower dementia risk, supporting the hypothesis that inflammation contributes to cognitive decline. This further supports earlier research which has shown that some genes that increase dementia risk are part of the inflammatory pathways.
Conflicting evidence was found for other classes of medications, with some blood pressure medications and antidepressants, and some diabetes medications showing decreased risk, while others were associated with increased dementia risk.
While the findings are intriguing, the research team noted the findings do not provide concrete evidence of causality.
“Because a particular drug is associated with an altered risk of dementia, it doesn’t necessarily mean that it causes or indeed helps in dementia,” said Ilianna Lourida, PhD, co-first author and a research fellow in precision dementia medicine at the University of Exeter Medical School. “It’s important to remember that all drugs have benefits and risks. You should never change your medicine without discussing this first with your doctor, and you should speak to them if you have any concerns.”
The researchers noted that this study is the largest of its kind to date and the findings can be used to help prioritize which drug repurposing candidates have the most potential.
“Pooling these massive health data sets provides one source of evidence which we can use to help us focus on which drugs we should try first,” Underwood said. “We’re hopeful this will mean we can find some much-needed new treatments for dementia and speed up the process of getting them to patients.”
