Popular high blood pressure drug linked to increased risk of skin cancer

Have you been using Hydrochlorothiazide? Hydrochlorothiazide — one of the most popular high blood pressure drugs in Australia — may be linked with an increase in developing skin cancer among older Australians, a new study by UNSW Sydney researchers found.

The drug contains photosynthesising properties, which can make the skin more sensitive to the sun. For the study, the researchers compared hydrochlorothiazide use in people who had been diagnosed with lip cancer or malignant melanoma compared with those with neither diagnosis. The findings were published in the journal Basic & Clinical Pharmacology & Toxicology.

“We found an increased risk for developing malignant melanoma and squamous cell cancer of the lip (lip cancer) with hydrochlorothiazide use,” lead author Dr Benjamin Daniels said. “For lip cancer, the risk also appears to be cumulative — that is, the longer that hydrochlorothiazide is used, the higher the risk of developing lip cancer.”

However, Dr Daniels cautioned strongly against stopping the popular medication without receiving medical advice from a doctor first, adding the skin cancer risk is something for prescribers and patients to be aware of.

“Hypertension is a condition that needs to be carefully managed,” he said. “We don’t want anyone to suddenly stop taking hydrochlorothiazide out of fear of developing skin cancer.

“The skin cancer risk is something for prescribers to be aware of. Doctors may want to consider conducting more skin checks for their patients or reinforcing advice around sun-smart behaviours that everyone should be aware of, like adequate protection when UV is higher than three and avoiding sun exposure during peak UV times.”

He continued: “By informing physicians around the potential risk of skin cancer in Australia associated with this common treatment, we hope our findings can help improve the care of patients dealing with hypertension.”

Meanwhile, a spokesperson from the Therapeutic Goods Administration (TGA) added the new findings will help prescribers and patients to make informed decisions, saying: “This [update] will help prescribers and patients to make informed choices about the benefits and risks of hydrochlorothiazide-containing medicines.”

High blood pressure, or hypertension, is considered the biggest contributor to cardiovascular death and disease worldwide, affecting about six million adult Australians. It accounted for about 10.4 million deaths in 2017 and currently affects more than a billion adults globally with the figure forecast to reach 1.5 billion by 2025. Management of the illness generally requires prescribed medicine, like hydrochlorothiazide, alongside lifestyle changes like eating a healthier diet and getting regular exercise.

IMPORTANT LEGAL INFO This article is of a general nature and FYI only, because it doesn’t take into account your personal health requirements or existing medical conditions. That means it’s not personalised health advice and shouldn’t be relied upon as if it is. Before making a health-related decision, you should work out if the info is appropriate for your situation and get professional medical advice.