Surprising New Research Links Common Medications to Reduced Dementia Risk

New research suggests that commonly used medications like antibiotics, antivirals, and anti-inflammatories could lower the risk of dementia.

This new study leverages data from over 130 million people, indicating that repurposing these drugs might fast-track effective treatments and alleviate the global dementia burden, potentially revolutionizing care for this devastating condition.

Promising Repurposed Drugs for Dementia

New research analyzing health data from over 130 million people suggests that antibiotics, antivirals, vaccines, and anti-inflammatory medications may be linked to a reduced risk of dementia.

The study, led by scientists from the University of Cambridge and the University of Exeter, identified several existing, approved drugs with potential to be repurposed for dementia treatment.

Dementia is one of the leading causes of death in the UK, significantly impacting individuals and their caregivers. The global economic burden of dementia is estimated to exceed $1 trillion.

Despite extensive research efforts, progress in finding drugs that can slow or prevent dementia has been limited. Until recently, available treatments primarily managed symptoms with only modest effects. New drugs, such as lecanemab and donanemab, have shown promise in slowing the progression of Alzheimer’s disease by reducing the buildup of amyloid plaques in the brain—a hallmark of the condition. However, the National Institute for Health and Care Excellence (NICE) determined that their benefits were not sufficient to warrant approval for use within the NHS.

Accelerating Dementia Treatment with Known Drugs

Scientists are increasingly turning to existing drugs to see if they may be repurposed to treat dementia. As the safety profile of these drugs is already known, the move to clinical trials can be accelerated significantly.

Dr. Ben Underwood, from the Department of Psychiatry at the University of Cambridge and Cambridgeshire and Peterborough NHS Foundation Trust, said: “We urgently need new treatments to slow the progress of dementia, if not to prevent it. 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. The fact they are already available is likely to reduce cost and therefore make them more likely to be approved for use in the NHS.”

Systematic Review Reveals Potential Dementia Prevention

In a study published today (January 21) in Alzheimer’s and Dementia: Translational Research & Clinical Interventions, Dr. Underwood, together with Dr. Ilianna Lourida from the University of Exeter, led a systematic review of existing scientific literature to look for evidence of prescription drugs that altered the risk of dementia. Systematic reviews allow researchers to pool several studies where evidence may be weak, or even contradictory, to arrive at more robust conclusions.

In total, the team examined 14 studies that used large clinical datasets and medical records, capturing data from more than 130 million individuals and 1 million dementia cases. Although they found a lack of consistency between studies in identifying individual drugs that affect the risk of dementia, they identified several drug classes associated with altered risk.

Insights and Implications from Drug Research

One unexpected finding was an association between antibiotics, antivirals, and vaccines, and a reduced risk of dementia. This finding supports the hypothesis that common dementias may be triggered by viral or bacterial infections, and supports recent interest in vaccines, such as the BCG vaccine for tuberculosis, and decreased risk of dementia.

Anti-inflammatory drugs such as ibuprofen were also found to be associated with reduced risk. Inflammation is increasingly being seen to be a significant contributor to a wide range of diseases, and its role in dementia is supported by the fact that some genes that increase the risk of dementia are part of inflammatory pathways.

The team found conflicting evidence for several classes of drugs, with some blood pressure medications and anti-depressants and, to a lesser extent, diabetes medication associated with a decreased risk of dementia and others associated with increased risk.

Caution and Future Research Directions

Dr. Ilianna Lourida from the National Institute for Health and Care Research Applied Research Collaboration South West Peninsula (PenARC), University of Exeter, said: “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. We know that diabetes increases your risk of dementia, for example, so anyone on medication to manage their glucose levels would naturally also be at a higher risk of dementia – but that doesn’t mean the drug increases your risk.

“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 conflicting evidence may also reflect differences in how particular studies were conducted and how data was collected, as well as the fact that different medications even within the same class often target different biological mechanisms.

The UK government is supporting the development of an Alzheimer’s trial platform to evaluate drugs rapidly and efficiently, including repurposed drugs currently used for other conditions.

“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,” said Dr. Underwood. “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.”

Reference: “Data-driven discovery of associations between prescribed drugs and dementia risk: A systematic review” by Benjamin R. Underwood, Ilianna Lourida, Jessica Gong, Stefano Tamburin, Eugene Yee Hing Tang, Emad Sidhom, Xin You Tai, Matthew J. Betts, Janice M. Ranson, Margarita Zachariou, Olajide E. Olaleye, Saswati Das, Neil P. Oxtoby, Shanquan Chen, David J. Llewellyn and , 21 January 2025, Alzheimer’s & Dementia: Translational Research & Clinical Interventions.