Viagra and Cialis in the Risk Reduction for Alzheimer’s—An Unfinished Story

The Alzheimer’s Solution Revolution Podcast

Summary

Hello and welcome to episode #19!

This is Ralph Sanchez and today I’ll be talking the outcomes of two recent studies that investigated the potential use of Viagra and Cialis in the risk reduction for late-onset Alzheimer’s disease (LOAD).

I was in part inspired to provide an overview on these two recent studies as they are cautionary tales on how many studies do not include the interrelated factors that are essential in arriving to an integrated assessment and analysis that serves their very premise— which is, does this or that work in a potential solution to something else?

Does Viagra or Cialis offer any proposed solution to the risk for LOAD and dementia?

Well today, I’ll be adding a great deal of information—the missing pieces to the puzzle as it were—with regard the pathways by which Viagra and Cialis may or may not work, and many other complimentary or natural alternatives that play a similar role in maintaining and optimizing a healthy cardiovascular and cerebrovascular system.

First, let me provide a little insight as to the molecular pathways in which drugs like Viagra and Cialis function, and why they may be considered as repurposed drug candidates for the treatment or in the risk reduction for LOAD.

Viagra (sildenafil) and Cialis (tadalafil) are Phosphodiesterase-5 inhibitors (PDE5is) which fall into a class of drugs that are normally prescribed to men to treat erectile dysfunction (ED), benign prostatic hyperplasia (BPH) and lower urinary tract symptoms (LUTS).

PDE5is can have a profound effect on cardiovascular health and PDE5is mediate their benefits by inhibiting the breakdown of a molecule, cyclic GMP (cyclic 3′,5′ guanosine monophosphate).

Cyclic GMP (cGMP) is an intracellular and second messenger molecule that modulates many downstream pathways, including significant effects in vasorelaxation—the ability of your blood vessels to dilate and expand as needed.

The vascular effect that is enabled by PDE5i-induced vasodilation is a pivotal pathway in vascular homeostasis and a healthy heart-brain axis.

And that vasodilation effect is how PDE5is improve and treat ED.

There is a lot more to that vasodilation benefit mediated by PDE5i therapy which I’ll get to here soon.

So on to a brief description of the two recent studies on Viagra and Cialis, and so much more that was not included in those studies that will provide a crucial insight into how you can improve your vascular health and reduce your risk for LOAD.

NIH Studies

First, a recent (2021)National Institutes of Health (NIH) funded study reported a risk reduction benefit of 69% for Alzheimer's disease (AD) in users of Viagra (Sildenafil).

The analysis simply compared Viagra users to those who did not take it, and the study was focused on a screen of drugs that could potentially be repurposed in the risk reduction for AD in aging individuals.

In a similar and second NIH funded study published this year (2022) titled— Drug Repurposing for Effective Alzheimer’s Medicines—(DREAM), the NIH analyzed data from Medicare beneficiaries that were treated with Viagra and Cialis.

The NIH team compared people with pulmonary arterial hypertension (PAH) treated with Viagra and Cialis over those with PAH on another class of drugs (endothelin receptor antagonists) used to treat pulmonary hypertension.

And note that PAH is a term that refers to high blood pressure in the blood vessels leading from the heart to the lungs

Yes, PDE5is are also prescribed to patients to reduce blood pressure in PAH, and off-label use of PDE5 inhibitors (PDE5is) is used to treat cardiovascular diseases, Raynaud’s disease and women with female sexual arousal disorder.