Viagra, the shingles vaccine and a motor neurone disease drug could help tackle Alzheimer’s, research suggests.
If proven to be effective, the medicines could be fast-tracked for NHS use and transform the lives of one million Britons living with dementia – which is the UK’s biggest killer.
Making drugs from scratch can take ten to 15 years and cost billions of pounds, with no guarantee they will work.
But repurposing medicines already approved for other conditions offers a quicker, safer and cost-effective route to potential treatments for dementia.
A panel of academics, doctors and patients examined 80 existing treatments to identify those mostly likely to help tackle Alzheimer’s – for which there is currently no cure.
The team decided to further investigate three drugs that showed promise after several rounds of review, according to the findings published in the Alzheimer’s Research journal.
These were selected as they target relevant aspects of the disease, did well in cell and animal studies and are known to be safe for the elderly.
The shingles vaccine (Zostavax) was selected as research suggests a link between the virus and dementia when it comes to changes in the immune system.
Sildenafil, also known as Viagra, helps protect nerve cells and reduces build up of the toxic protein tau in the brain. In tests involving mice, it also improved cognition – thought to be due to it increasing blood flow to the brain.
MND drug Riluzole also showed promising results in reducing levels of tau in animal studies.
The experts, led by Professors Clive Ballard and Anne Corbett at the University of Exeter, recommended that these drugs now be tested in clinical trials to understand their benefit for those with or at risk of Alzheimer’s disease.
The shingles vaccine was deemed to be the most promising – particularly as it requires a maximum of two doses and has a strong safety record.
Viagra is one of three medicines that could be repurposed to reverse or prevent Alzheimer’s
Dr Corbett said: ‘Beating dementia will take every avenue of research – from using what we already know, to discovering new drugs to treat and prevent the condition.
‘Drug repurposing is a vital part of that mix, helping us turn today’s medicine for one condition into tomorrow’s treatment for another.
‘It’s important to stress that these drugs need further investigation before we will know whether they can be used to treat or prevent Alzheimer’s.
‘We now need to see robust clinical trials to understand their true value and know for certain if they are effective to treat or prevent Alzheimer’s.’
They now hope to carry out a large clinical trial of this shingles vaccine in the UK.
Professor Fiona Carragher, chief policy and research officer at Alzheimer’s Society, which part-funded the study, said: ‘Dementia devastates lives, but we believe research will beat it.
‘Currently, there is no cure for dementia. Finding new treatments from scratch can be a long and expensive process, and many experimental treatments can fail safety and effectiveness studies.
‘Years ago, we saw aspirin being repurposed from being a painkiller to helping people reduce their risk of heart attack or stroke. This is what we now want to see in the field of dementia.
‘The progress being made through drug repurposing, combined with the breakthroughs we’ve seen this year with disease modifying treatments like lecanemab and donanemab, means there are more reasons for hope than ever before.’
