Existing Shingles Vaccine, Viagra, and MND Drug Identified as Potential Alzheimer's Treatments

Repurposed Drugs: Three Existing Medications Show Promise for Alzheimer's

Researchers have identified three existing medications that show potential for repurposing to treat or prevent Alzheimer's disease. This innovative approach involves examining currently approved drugs for other conditions, rather than developing entirely new ones from scratch.

The significant study, funded by Alzheimer's Society and led by the University of Exeter, was published in the journal Alzheimer's Research and Therapy. The most promising candidates identified include a shingles vaccine (Zostavax), sildenafil (Viagra), and riluzole, a medication typically used for motor neurone disease.

"Using existing approved medications could offer a faster, safer, and more affordable path to new treatments for Alzheimer's."

The Significance of Drug Repurposing

Drug repurposing is considered a crucial strategy in the fight against dementia, a leading cause of death globally. Developing new drugs is not only immensely costly but also incredibly time-consuming, often taking over a decade. By utilizing existing, approved medications, researchers hope to accelerate the discovery of new treatments, providing a more efficient route to help those affected by Alzheimer's.

Rigorous Selection Process

An international panel of 21 dementia specialists and individuals with lived experience of dementia meticulously evaluated 80 existing medications. From this extensive list, they carefully selected three 'priority candidates'. Their decisions were based on specific criteria: the drug's ability to target biological processes linked to Alzheimer's, encouraging results observed in cell and animal studies, and their proven safety profile, particularly in older adults.

Three Priority Candidates Identified

Studies suggest a compelling connection between the shingles virus and dementia. This vaccine is thought to interact with the immune system in ways that could potentially counteract changes associated with Alzheimer's disease. Previous research indicates that individuals who received the shingles vaccine were approximately 16% less likely to develop dementia.

Beyond its known use, research suggests sildenafil may protect nerve cells and reduce the buildup of tau protein, a key marker of abnormal brain changes in Alzheimer's. Mouse studies have shown promising results, including improved thinking and memory, potentially due to enhanced blood flow to the brain.

Currently prescribed for motor neurone disease, riluzole has demonstrated potential in animal studies. In these studies, the drug has improved cognitive performance and led to lower levels of tau protein, suggesting a role in mitigating some aspects of Alzheimer's pathology.

Next Steps: Clinical Trials

Experts are now strongly advocating for robust clinical trials to determine the effectiveness of these medications in people with or at risk of Alzheimer's. These human trials are essential to confirm the initial promising findings.

The shingles vaccine, in particular, is considered a strong candidate for a large-scale UK clinical trial, potentially leveraging the PROTECT online registry for participant recruitment.

Other Shortlisted Candidates

In addition to the three priority candidates, five other medications were shortlisted by the panel but did not advance to priority status. These included fingolimod, vortioxetine, microlithium, dasitinib, and cytisine.

Researchers emphasize that further robust clinical trials are absolutely necessary to confirm the true value and effectiveness of these drugs for treating or preventing Alzheimer's disease.