Viagra remains one of the most popular drugs for treating erectile dysfunction or ED. The drug is quite safe and has been used by millions of men world wide. Recently there was a report of a relationship between Viagra and the potentially lethal skin condition, melanoma.
A potential link between erectile dysfunction drugs and melanoma may exist, but inconsistencies in the data make a cause-and-effect relationship questionable.
Men who had a history of using phosphodiesterase type 5 (PDE5) inhibitors (Viagra, Levitra, or Cialis) had a 20% greater risk of melanoma as compared with men who never used the drugs. However, the strongest association involved men who filled a single prescription for a PDE5 inhibitor. Total number of prescriptions filled did not significantly affect melanoma risk.
Moreover, the PDE5 inhibitor-melanoma association pertained only to early-stage disease (stage 0-I), did not differ by type of PDE5 inhibitor, and was not limited to melanoma, as an increased risk of basal cell carcinoma was seen among users of PDE5 inhibitors. This was reported online in The Journal of the American Medical Association.
The findings are consistent with those of a similar study reported a year ago. However, the previous study was based on data that showed only whether a man had ever used a PDE5 inhibitor. Extracted from the Health Professionals Follow-up Study, the data were limited to the original PDE5 inhibitor, sildenafil (Viagra), and lacked details about use of the drug, such as the number of prescriptions filled.
The study was not able to prove cause and effect relationship. A longer follow-up and more detailed assessment of the dose and frequency of Viagra use at multiple times in the would be necessary for future studies.
In theory, a causal association between PDE5 inhibitor use and melanoma has biologic plausibility. Several studies have provided evidence of interaction between PDE5 and melanoma.
A Swedish study of the 435 men who used PDE5 inhibitors and developed melanoma, 275 had filled one or more prescriptions for sildenafil and 224 had filled at least one prescription for Levitra or Cialis.
Overall, men who used PDE5 inhibitors had a slight increase for melanoma versus nonusers. The risk of melanoma did not differ significantly across the three types of ED drugs.
Bottom Line: What’s my advice. Whether you use Viagra, Levitra, or Cialis, or not, I suggest you make use of plenty of sun screen. Nothing less than a SPF of 35. Also, if you are at risk for melanoma, i.e., are light completed, have frequent exposure to sun, then see a dermatologist at least once a year for a total body examination.