Since coming onto the market and revolutionising the treatment of erectile dysfunction, Viagra has been found useful for other purposes, such as the treatment of hypertension. It is now emerging as a potential treatment for Alzheimer’s disease.
Researchers from Mount Sinai Medical Center in New York have demonstrated in a new study that Viagra (the brand name of sildenafil), a drug most commonly used to treat erectile dysfunction, can block an enzyme found in the brains of those with Alzheimer’s disease.
The researchers say blocking this particular enzyme results in an up to 60 per cent reduction in the risk of developing Alzheimer’s.
The study involved more than 27,000 people aged 65 and over, split into two groups. Half of the participants had been prescribed sildenafil while the other half had not.
Results showed that participants taking Viagra had greatly reduced levels of a protein called PDE5. In Alzheimer’s patients, PDE5 levels are significantly increased in the part of the brain that manages memory.
“We found sildenafil was significantly associated with a 60 per cent lower risk of developing Alzheimer’s disease,” says lead study author Xingyue Huo.
Results echo previous study
The results echoed a previous study that found sildenafil cannot only lower your risk of Alzheimer’s, but also shows promise in the treatment pulmonary hypertension.
Researchers from the Cleveland Clinic screened and validated over 1600 drugs approved for use by the US Food and Drug Administration (FDA) and used them in an analysis of a database containing more than seven million patients.
The drugs that scored the highest on these tests were the ones that targeted both the amyloid and tau proteins – two of the hallmarks of Alzheimer’s disease.
They then determined that sildenafil was associated with a 69 per cent reduced incidence of these biomarkers.
Alzheimer’s disease is the most common form of dementia in Australia, accounting for around 70 per cent of the 400,000-plus dementia sufferers in the community.
Using computational methodology, the research team was able to examine the relationship between sildenafil and Alzheimer’s disease outcomes by comparing users of the drug with non-users.
They found that sildenafil users were 69 per cent less likely to develop Alzheimer’s disease than non-sildenafil users after a six-year follow-up period.
“Notably, we found that sildenafil use reduced the likelihood of Alzheimer’s in individuals with coronary artery disease, hypertension and type 2 diabetes, all of which are comorbidities significantly associated with risk of the disease, as well as in those without,” said Dr Feixiong Cheng, the study lead.
To further explore their findings, the researchers developed an Alzheimer’s patient-derived brain cell model using stem cells.
Brain cell growth
In the model, they found that sildenafil increased brain cell growth and decreased one of the significant causes of tau tangles in the brain.
“Because our findings only establish an association between sildenafil use and reduced incidence of Alzheimer’s disease, we are now planning a mechanistic trial and a phase II randomised clinical trial to test causality and confirm sildenafil’s clinical benefits for Alzheimer’s patients,” said Dr Cheng.
He said the team would also investigate whether the same approach could be used for other neurodegenerative diseases such as Parkinson’s disease.
Do you use any erectile dysfunction drugs? Did you know these drugs could help protect you from Alzheimer’s disease? Let us know in the comments section below?
Also read: Parkinson’s breakthrough detects disease decades earlier
Did the trial include females?