Viagra, the world’s #1 selling drug for erectile dysfunction, also shows
potential in treating heart disease and cancer. The drug works by inhibiting
an enzyme called PDE5. What is PDE5 and what does it do? Let’s explore.
The Enzyme PDE5
PDE5 deacylates cyclic guanosine monophosphate (cGMP) to form linear
guanosine monophosphate (GMP). This helps elevate nitric oxide (NO) levels,
which relaxes and dilates blood vessels. As you’ll learn below, PDE5 also deacylates
cAMP, the so-called “inverse” metabolite of cGMP. This helps explain why
Viagra is effective in treating ED and other conditions.
Why Viagra Works For ED)
You may be wondering why Viagra is effective in treating erectile
dysfunction (ED). Well, it turns out that Viagra works for ED because it inhibits
PDE5. Specifically, Viagra binds to PDE5, blocking it from doing its
maintenance work and preventing its over-activation. As a result, cGMP
accumulates in cells, which then stimulates the relaxation of smooth muscle
in blood vessels throughout the body. What’s more, researchers have also
demonstrated that Viagra’s effects may help protect against heart disease,
high blood pressure, and Alzheimer’s disease.
How Does Viagra Work For Heart Disease)
In a similar fashion to how Viagra works for ED, there is also
evidence to suggest that Viagra may work for heart disease. Scientists have
found that PDE5 inhibits cardiac fibroblast apoptosis (cell death) and
migration. In other words, Viagra prevents cardiac fibroblasts from
self-destructing and clogging up the heart. This may help explain why
patients who took Viagra showed improvements in ejection fraction, the
ability of the heart to pump blood, after cardiac-related surgeries.
How Does Viagra Work For Cancer)?
A growing body of evidence suggests that PDE5 may also help prevent
cancer. Specifically, PDE5 inhibits the growth of prostate cancer cells,
as well as breast, liver, and lung cancer cells. In other words, Viagra
has the potential to be used to treat a variety of cancers.
The Role Of PDE5 Inhibitors In ED Therapy
Because it is effective in treating ED and due to its safety
profile, many doctors and patients might believe that Viagra is the
perfect drug for treating ED. However, this is not the case. As a matter of fact,
patients with ED should not and cannot take Viagra without first trying
a PDE5 inhibitor.
Why? Although Viagra can help increase blood flow to certain areas of the body,
it can also cause problems. For example, excessive concentrations
of cGMP may cause blood vessels to dilate too much, leading to
potentially dangerous consequences. Similarly, because of its
stimulating effects on the nervous system, Viagra may cause
shorter-term side effects such as headache, flushing, and anxiety.
Finally, due to its effects on the central nervous system,
Viagra may also cause long-term side effects such as depression
and addiction.
If you have ED and are considering taking Viagra, then try
one of the following medications instead: