Taking these common drugs can quadruple your risk of skin cancer

A skin cancer trigger might be in your medicine cabinet: People who take a common blood pressure medication may be at higher risk of developing the condition, a new study published in the Journal of American Dermatology suggests.

Researchers analyzed usage of a specific blood pressure drug called hydrochlorothiazide (known by the brand name Microzide) in over 80,000 people with non-melanoma skin cancer—both basal cell carcinoma and squamous cell carcinoma—and compared that to data from 1.5 million people without skin cancer.

They discovered that high usage of hydrochlorothiazide, (the equivalent of taking it continuously for about six years or more) was linked to four times the risk of squamous cell carcinoma and a 29 percent increased in basal cell carcinoma.

And the skin cancer risk grew the longer they were exposed to the drug and the higher the dose, the researchers found. And the link was even stronger in people under 50, who tend to have lower chances of getting non-melanoma skin cancer to begin with.

Both basal cell and squamous cell carcinomas tend to develop on sun-exposed areas, like your face, ears, and neck. They’re way more common than the deadliest form of skin cancer, melanoma—which accounts for just one percent of all skin cancer—but are also much less likely to spread.

In fact, nearly 10,000 people each year are expected to die from melanoma, compared to just 2,000 for basal cell and squamous cell carcinomas combined, according to the American Cancer Society.

So why the link? The researchers believe that one of the side effects of hydrochlorothiazide is photosensitivity, or an increase in sensitivity to the sun’s radiation.

“This might lead to tenderness after sun exposure or actual sun burns,” says study a author Anton Pottegård, Ph.D. “Such skin damage is one of the main pathways leading to skin cancer, in particular [to] squamous cell carcinoma.”

More research is needed before experts can draw any firm prescribing changes for hydrochlorothiazide based on these findings, he says. But in the meantime, guys who are at higher skin cancer risk to begin with—say, if they’ve already been diagnosed with basal cell carcinoma or squamous cell carcinoma while taking hydrochlorothiazide—may want to ask their doctor about other options for treating high blood pressure.

Researchers didn’t find any link between skin cancer and other blood pressure drugs, like ACE inhibitors, calcium channel blockers, or angiotensin II antagonists.

So if you fit the bill, you can ask your doctor about possibly switching to another medication. But as with any drug, don’t discontinue your treatment without talking to your doctor first, says Pottegård.