Erectile dysfunction drugs such as Viagra could be inadvertently cutting the chances of men developing Alzheimer’s disease, research suggests.
Alzheimer’s Research UK called the findings “encouraging,” saying the chance of repurposing drugs to tackle the condition could help “accelerate progress and open up new avenues to prevent or treat dementia-causing diseases”.
However the charity said more research is needed to confirm the results and examine the impact the drugs could have on women and others.
In the study, published in the journal Neurology, University College London (UCL) experts examined the medical records of 269,725 men aged over 40 – with an average age of 59 – who were diagnosed with erectile dysfunction between 2000 and 2017.
More than half of those sampled had been prescribed a type of medication known as a PDE5I drug (phosphodiesterase type 5 inhibitors), which includes Viagra, Cialis, vardenafil and avanafil.
In a follow-up period averaging 5.1 years, 1,119 of the men were diagnosed with Alzheimer’s.
Statistical analysis from UCL found that the men taking the drugs were 18% less likely to develop the disease compared with those who had erectile dysfunction but did not take the drugs.
UCL also found that those prescribed “most frequently” were even less likely to be diagnosed with Alzheimer’s.
Lead author Dr Ruth Brauer, from the UCL School of Pharmacy, said: “Although we’re making progress with the new treatments for Alzheimer’s disease that work to clear amyloid plaques in the brain for people with early stages of the disease, we desperately need treatments that can prevent or delay the development of Alzheimer’s disease.
“More research is needed to confirm these findings, learn more about the potential benefits and mechanisms of these drugs and look into the optimal dosage.
“A randomised, controlled trial with both male and female participants is warranted to determine whether these findings would apply to women as well.”
Making Alzheimer’s drugs ‘can take many years’
Dr Leah Mursaleen, head of research at Alzheimer’s Research UK, said that “developing drugs for diseases like Alzheimer’s is a costly process and can take many years”.
She added: “While this is an encouraging finding, it doesn’t yet confirm whether these drugs are directly responsible for reducing Alzheimer’s risk, nor whether they can slow or stop the disease.
“Further research – including clinical trials – will be needed to confirm whether these drugs can indeed play a role in preventing or treating Alzheimer’s.
“Such studies should also uncover whether these drugs might have effects in other groups, such as women, and men without a diagnosis of erectile function. We also need to understand how this evidence might apply to more diverse populations.”
Men with a previous diagnosis of dementia or cognitive impairment were not included in UCL’s analysis.
Researchers noted that previous animal research found PDE5I drugs have some “neuroprotective benefits”.
