Drugs like Cialis used for erectile dysfunction are getting more attention than they used to, due to recent research suggesting they may contribute to melanoma.

Cialis is one of a group of erectile dysfunction drugs known as phosphodiesterase type 5 inhibitors, or PDE5 inhibitors.

Researchers note that as a class, PDE5 inhibitors promote the synthesis of melanin, which itself can exacerbate melanoma development.

Originally approved by the FDA in November 2003, Cialis is now used to remedy erectile dysfunction and to relieve some symptoms of benign prostatic hypertrophy.

It works by relaxing the muscles within the walls of blood vessels, thereby increasing blood flow.

It’s also known by its generic name tadalafil, the same drug sold under the brand name Adcirca as a treatment for pulmonary arterial hypertension.

Like other erectile dysfunction drugs, Cialis has been a reliable moneymaker. Manufacturer Eli Lilly enjoyed Cialis sales reaching $2.3 billion in 2014.

Research on Cialis and Melanoma

Some recent scientific research has raised the question of whether Cialis side effects might include increased risk of developing melanoma, one of the more aggressive forms of skin cancer.

One article published in JAMA in 2015 studied the use of several different PDE5 inhibitors, including tadalafil, in search of a possible link to skin cancer.

Researchers examined the histories of 4,065 men with records in several national healthcare databases in Sweden. Of those men, 435 had filled prescriptions for PDE5 inhibitors.

The researchers found a significant association between use of PDE5 inhibitors and an increased risk of melanoma.

They found the most pronounced increase in risk among men who had filled just a single prescription: these men faced a 21 percent increase in risk. Tadalafil was associated with an increase in risk comparable to that of other PDE5 inhibitors, the researchers found.

A more recent article published in Cell Reports in March 2016 concluded that while drugs like Cialis may not be a root cause of melanoma, they could contribute to the progression of existing disease.

The researchers also note the results of an earlier study from 2014, in which scientists found that among almost 15,000 men in the U.S., those who used sildeniafil (another type of PDE5 inhibitor) had a significantly elevated risk of melanoma.

Melanoma is one of the less common types of skin cancer in the U.S. Even so, it’s responsible for the largest number of skin cancer-related deaths: about 10,000 people die from melanoma every year.

It typically manifests as a small, new growth, usually on sun-exposed skin. If it’s caught early, the odds of survival are fairly good: almost all of the earliest melanomas are successfully treated with surgery.

But melanoma can grow and spread very rapidly. If allowed to progress and metastasize to other parts of the body, the patient’s odds of survival plunge.

Despite the recent research results, the product information for Cialis does not yet mention melanoma or any other type of skin cancer in its information on Cialis side effects.

The only skin symptoms mentioned in the “Adverse Reactions” section are pruritus, rash and sweating.

search results, the product information for Cialis does not yet mention melanoma or any other type of skin cancer in its information on Cialis side effects. The only skin symptoms mentioned in the “Adverse Reactions” section are pruritus, rash and sweating.