A man has filed a lawsuit alleging a link between his use of Viagra and melanoma diagnosis.

Plaintiff Paul B. alleges he took Pfizer’s Viagra and Eli Lilly’s Cialis from January 2000 through June 2014 to treat erectile dysfunction. He was diagnosed with the potentially deadly skin cancer melanoma in September 2008.

Both Viagra and Cialis are PDE5 inhibitors. By blocking the secretion of the PDE5 enzyme, blood flows more easily to the areas needed to resolve erectile dysfunction.

Melanoma is a potentially deadly skin cancer linked to repeated sun exposure. A suspected link between Viagra and melanoma has been reported for years, but many doctors and consumers assumed a man who took Viagra led a lifestyle more apt to lend him to increased sun exposure. Even though erectile dysfunction can occur at any age, the issue is more apt to be associated with older men who have more time for leisurely activities such as golfing and boating often enjoyed in sunny conditions.

Link Between Viagra and Melanoma Discovered in 1990s

Several studies linked Viagra and melanoma in the late 1990s. In fact, Pfizer knew several men dropped out of Viagra clinical studies because they developed cancer, including melanoma.

In 2011, a study found that Viagra spurs melanoma to invade cells because of the inhibition of PDE5. By inhibiting PDE5, Viagra imitates the effect of gene activation that triggers the creation of melanoma cancer cells, claims the Viagra and melanoma lawsuit.

Viagra and other PDE5 inhibitors allow the proliferation of melanin, the pigment that makes skin turned tan after sun exposure. The increased melanin production allegedly spurs the creation of melanoma cancer cells.

“Pfizer purposefully downplayed, understated and outright ignored the melanoma-related health hazards and risks associated with using Viagra,” says the Viagra and melanoma lawsuit. “Pfizer concealed material information related to melanoma development from potential Viagra prescribers and users.”

The Viagra and melanoma MDL says Pfizer purposefully deceived the drug’s audience by pushing positive information through a variety media outlets. The alleged deception included the publication of testimonials from popular U.S. politicians who had retired.

Plaintiffs like Paul claim that Pfizer never mentions any potential increased risk of melanoma or exacerbation of existing melanoma affiliated with Viagra use on the drug’s label, package inserts or warnings.

The Viagra and melanoma lawsuit indicates that if doctors had known the dangers of taking Viagra, they would not have prescribed the erectile dysfunction drug or at the very least, would have discussed the increased risk of melanoma. Such a conversation might have led Paul and other plaintiffs to determine the risks were not worth the benefits of taking Viagra.

The Viagra and Melanoma Lawsuit is Case No. 3:18-cv-01838-RS and is part of the Viagra and Cialis MDL, In re: Viagra (sildenafil citrate) and Cialis (tadalafil) Products Liability Litigation, MDL No. 2691, in the U.S. District Court for the Northern District of California, San Francisco Division.