Scientists think that it comes about by a faulty gene suppressing this enzyme, which means that shutting off PDE5 may have the unintended side effect of increasing the risk that melanoma could develop.
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The researchers detailed their findings in the Journal of the American Medical Association. As a outcome, Dr. Loeb has gathered a collection of 20,000 medical records of Sweden medical patients to study their evolution from 2006 to 2012. They specifically zeroed in on the records of more than 20,000 Swedish men, most of whom were white. The answer, said Loeb, probably lies in lifestyle. The most pronounced increase in risk was observed in men who had filled a single prescription – an overall increased risk of 21%. “And since their lifestyle may involve more travel and exposure to the sun, they may be at a higher risk for developing melanoma”, said Loeb.
The study suggests that the risk of melanoma among erectile dysfunction drugs users was modest.
Then they looked at what’s known in medical circles as “dose response”. Of the three ED drugs, Cialis has the longest half-life, Loeb explains.
Past studies have revealed that around 14 men developed malignant melanoma after treating their erectile dysfunctions with well-known drugs, such as, Viagra and related compounds. These men were selected randomly from the same registry and were matched by age. When Viagra isn’t covered, it can cost up to $50 a pill. Even when the insurance companies cover the medicine, they often end up charging the highest possible co-pay. Stacy Loeb, an urologist at New York University, wasn’t convinced though. She found the melanoma risk among men taking ED drugs was nearly identical to the risk of basal cell. To be sure this wasn’t just a hunch, the team also screened for another skin cancer called basal cell carcinoma. This study got a lot of publicity leading numerous patients to express concern over whether erectile dysfunction drugs could cause melanoma.
Phosphodiesterase type 5 (PDE5) inhibitors are the most commonly prescribed drugs for ED. This drug class includes sildenafil (brand name Viagra) and vardenafil (Levitra). The drug is already off patent in Europe, Japan and Australia, and the US patent is set to expire in 2020. It may be that those who travel are also more likely to use ED drugs.
That’s why Dr. Loeb and team wanted to test whether men who took these drugs had a raised risk of melanoma.
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Drugs like Viagra and Cialis work by turning off the enzyme PDE5 – a chemical which takes away an erection after sex by limiting blood supply.
