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Viagra, Levitra, Cialis May Cause Cancer: Study

Viagra May Cause CancerAs if erectile dysfunction were not harrowing enough. In March 2016 a published study concluded that the use of the drug sildenafil (Viagra), vardenafil (Levitra), and tadalafil (Cialis) “could promote melanoma in humans.”

As you probably know, melanoma is the most aggressive and most dangerous form of skin cancer. Melanoma develops when damage to skin cells (usually caused by ultraviolet radiation from sunshine or tanning beds) triggers mutations that lead the skin cells to multiply rapidly and form malignant tumors. Most people think of melanoma as dark, asymmetrical moles, and in fact melanoma can develop from existing moles, but melanoma can also form directly on the skin. Melanoma is often caused by intense, sustained exposure to ultraviolet light, the kind which causes suntans and sunburns. Melanoma has been estimated to cause over 10,000 deaths in the United States each year.

The Latest Study

Viagra May Cause MelanomaA team of researchers recently published findings from a study of the potential connection between the increased risk of melanoma in humans who take erectile dysfunction drugs like Viagra. The study is titled Sildenafil Potentiates a cGMP-Dependent Pathway to Promote Melanoma Growth, which you can access here. This study identified a pathway in the cells of the human body which can permit the growth of melanoma. The science behind the study is complex and technical, but let’s give it try:

Sildenafil (Viagra) is a phosphodiesterase 5 inhibitor (PDE5). When PDE5 is inhibited, a man has the enhanced ability to gain an erection. And that’s a good thing. Unfortunately, according to the study, the inhibition of PDE5 in the human body also increases the level of “cyclic guanosine-3′, 5′-monophosphate” (cGMP), which is described as “a signaling molecule,” and increased levels of cGMP in the body promotes “mitogen-activated protein kinase” (MAPK), which is a pathway in the molecules associated with the increased growth of melanoma cells. When PDE5 is not inhibited, there are low cGMP levels and less active melanoma growth. But when sildenafil or other drugs inhibit PDE5, it causes a molecular reaction which promotes the malignant growth of melanoma cells. So the inhibition of PDE5 increases cGMP levels, which promotes MAPK, which encourages melanoma cell growth. Got it?

Vardenafil (Levitra) and tadalafil (Cialis) are also PDE5 inhibitors. The study states that Levitra and Cialis would also operate like Viagra to promote melanoma cell growth through similar molecular reactions.

Other studies have linked the use of Viagra to an increased risk of melanoma, including one from the Journal of American Medical Association (JAMA) in 2014.

Viagra Maker Denies Increased Melanoma Risk

Pfizer is the manufacturer of Viagra, the first and most popular of the drugs used to treat erectile dysfunction. Pfizer has denied any increased melanoma risk, stating that Viagra has been studied in 136 clinical trials and that “there is no reliable scientific evidence that the medicine causes melanoma.” It is important to listen to the denial, as Pfizer states there is no reliable scientific evidence, which recognizes that there is scientific evidence; Pfizer thus discounts the existing scientific evidence as “unreliable.” Pfizer has stated that it stands behind “this important medicine” and intends to “vigorously defend these lawsuits.”

I also read one article which suggested that the Viagra lifestyle was the cause of the increased incidence of melanoma (and not the Viagra itself). The “Viagra lifestyle” was suggested to be a world where men would take their romantic partners to places like the Caribbean or on a boat, places where exposure to the sun’s damaging rays was higher. I would advise skepticism for this theory. I have not seen any evidence that men who use Viagra had better sun tans than those men who did not take Viagra, except on all the commercials.

The Lawsuits Are Mounting

In April, the U.S. Judicial Panel on Multidistrict Litigation created a MDL site in the Northern District of California for lawsuits from those alleging injury against Pfizer from the use of Viagra. Judge Richard Seeborg of San Francisco has been assigned to preside over the Viagra MDL. The central allegations are that (1) sildenafil increases the risk of developing melanoma and that (2) Pfizer failed to warn consumers and medical care providers of the risk. Originally fourteen cases were transferred to the Viagra MDL, but more are being filed each week.

Pfizer first sold Viagra in 1998. And to no one’s surprise, it became hugely popular and very profitable. In 2013 alone Pfizer made $1.8 billion dollars from the sale of Viagra worldwide. All this to say that many millions of men have taken Viagra over the past eighteen years. If the studies are accurate, this is an army of men more vulnerable to the onset of life-threatening skin cancers.

The Takeaway

Let’s face it, compromised conditions of aging, like bad knees or erectile dysfunction, can dramatically reduce a person’s quality of life. For years medications like Viagra seemed like a great way to extend an aging man’s ability to engage in sexual intercourse (which is a great thing to engage in). However, the most recent study of Viagra, coming as it does after other studies concluding that Viagra may increase the risk of melanoma, suggests that the use of erectile dysfunction drugs may not be worth it. Talk at length to your doctor about the risks of taking Viagra or Levitra or Cialis. Of course avoid excessive sun exposure and always wear sunscreen. Above all, keep a careful watch about any news reports of new studies linking Viagra and similar drugs to the onset of melanoma.