Reducing the Risk of Alzheimer’s with Viagra?

Surprising discovery: How a sexual enhancer could fight Alzheimer’s

Sometimes new findings can be found where you least expect them: a widely used drug for the treatment of erectile dysfunction could also play an unexpected role in the fight against Alzheimer’s disease.

A study by University College London has now shown that Viagra and similar erectile dysfunction drugs could significantly reduce the risk of developing Alzheimer’s disease. Under the direction of study leader Ruth Brauer, medical records of around 270,000 men, 59 years old on average, who had recently been diagnosed with erectile dysfunction were analyzed. 55 percent of the participants used appropriate medication, while 45 percent did not take such preparations.

The more frequent the prescription, the higher the risk reduction for Alzheimer’s

The research findings, published in the Neurology journal, reveal that men who were prescribed the active ingredient sildenafil – commonly known as Viagra – and other drugs containing PDE 5 inhibitors had an 18 percent lower risk of Alzheimer’s disease. The study also suggests that the risk reduction is dose-dependent: the strongest effect was seen in men who received between 21 and 50 prescriptions, for whom the risk fell by as much as 44 percent.

Encouraging approach of the active ingredient originally developed for high blood pressure

Leah Mursaleen from Alzheimer’s Research UK sees the study results as an encouraging approach, but emphasizes the need for further research to prove a causal link to the Alzheimer’s risk reduction by Viagra. The observational study does not clarify whether Viagra directly reduces the risk or influences the disease, and ignores the fact that men who are less susceptible to dementia may be more likely to take such medication. Important lifestyle factors were missing from the analysis, which could influence the results. Nevertheless, the discovery of the effect of Viagra and similar drugs is considered an important contribution to Alzheimer’s research, as they act as PDE5 inhibitors to promote blood flow.

PDE5 inhibitors: Alzheimer’s prevention not only for men, but also for women

The improvement in blood flow by Viagra, which was demonstrated in animal studies, suggests that sexual enhancers – the effect of sildenafil was also originally accidental when it was developed as a treatment for high blood pressure and angina pectoris – could also be useful for Alzheimer’s prevention. However, the results from human studies have so far been contradictory. While a study by the Cleveland Clinic in Ohio found a 69 percent reduction in the risk of Alzheimer’s in Viagra users, a parallel study at Harvard was unable to prove any protective effect.

Despite these uncertainties, experts believe that further research, particularly in women, is worthwhile as PDE5 inhibitors, if effective against Alzheimer’s, should work in both sexes. Therefore, experts emphasize the importance of further research, especially in women.

Difficult to conduct placebo-controlled studies due to clear effect

Ivan Koychev from the University of Oxford emphasizes the challenge of conducting placebo-controlled studies, as the effects of drugs such as Viagra are, after all, unmistakable, which makes blinding participants and doctors much more difficult.

Nevertheless, there is great interest in the repurposing strategy of using existing drugs to prevent dementia. Alzheimer’s Research UK sees the repurposing of approved drugs for other diseases as an opportunity to accelerate progress and find new prevention or treatment options for dementia.

Sources:

https://www.neurology.org/doi/10.1212/WNL.0000000000209131
https://www.alzheimersresearchuk.org/erectile-dysfunction-drugs-may-be-linked-to-reduced-risk-of-alzheimers-disease-study-suggests