Side Effects of HCTZ, Similar Blood Pressure Medications, May Increase Risk of Skin Cancer: Study

The findings of a new study suggest there may be a skin cancer risk associated with hydrochlorothiazide (HCTZ) and other thiazide-based drugs used for treatment of blood pressure.

In a report published this month in the Canadian Medical Association Journal (CMAJ), researchers with the University of Toronto sought to assess a long-held belief that there was some connection between thiazides, a class of antihypertensive medications, and an increased risk of skin cancer.

While the link has previously been unclear, the new findings appear to affirm those suspicions, finding a more than 30% increased risk of melanoma skin cancer among users of the blood pressure drugs.

Did You Know?

AT&T Data Breach Impacts Millions of Customers

More than 73 million customers of AT&T may have had their names, addresses, phone numbers, Social Security numbers and other information released on the dark web due to a massive AT&T data breach. Lawsuits are being pursued to obtain financial compensation.

Learn More

Researchers note the association has been indicated in previous studies, so this time they conducted a cohort study involving nearly a million adults ages 66 or older over a period of about 20 years. The study matched 302,634 adults prescribed an antihypertensive medication to 605,268 unexposed adults from 1998 to 2017.

The medications included thiazides, like HCTZ, as well as angiotensin-converting enzyme inhibitors, angiotensin II receptor blockers, calcium channel blockers and beta blockers. Researchers looked at the cumulative dose with each class and looked for diagnoses of keratinocyte carcinoma, advanced keratinocyte carcinoma and melanoma.

According to the findings, higher levels of thiazide exposure led to a slight increase in the risk of keratinocyte carcinoma; an increase of about eight percent. Advanced keratinocyte increased by a similar amount. However, the risk of melanoma, an often-deadly form of skin cancer, increased by 34%. No other blood pressure medications were associated with an increase in skin cancer, the researchers reported.

The researchers said that while ultraviolet (UV) radiation exposure was still the most important environmental risk factor associated with skin cancer, medication-induced phototoxicity, where a drug interacts with UV radiation to cause cellular skin damage, was something health care professionals and researchers should be concerned about.

“Higher cumulative exposure to thiazides was associated with increased rates of incident skin cancer in people aged 66 years and older,” the researchers determined. “Consideration of other antihypertensive treatments in patients at high risk of skin cancer may be warranted.”

The researchers noted that while many hypertension drugs are reported to be phototoxic, HCTZ is considered to be the most phototoxic of all blood pressure medications, and is often the first go-to medication for doctors treating patients for high blood pressure.


  • IwaMarch 25, 2022 at 2:09 am

    My mom was diagnosed over a year ago with a rare skin cancer Grzybowski’s syndrome. She’s been on HCTZ or a combo of it with another BP med. Could the two be linked? How would we find out?

Share Your Comments

I authorize the above comments be posted on this page*

Want your comments reviewed by a lawyer?

To have an attorney review your comments and contact you about a potential case, provide your contact information below. This will not be published.

NOTE: Providing information for review by an attorney does not form an attorney-client relationship.

This field is for validation purposes and should be left unchanged.

More Top Stories

Leadership Development Committee for Suboxone Dental Injury Lawyers Established in Federal MDL
Leadership Development Committee for Suboxone Dental Injury Lawyers Established in Federal MDL (Posted today)

The U.S. District Judge presiding over all Suboxone lawsuits has created a mentorship program to use the litigation to provide some attorneys an opportunity to gain experience in handling complex federal multidistrict litigations.

Gilead Settlement Resolves 2,625 HIV Drug Lawsuits Pending in Federal Courts for $40M
Gilead Settlement Resolves 2,625 HIV Drug Lawsuits Pending in Federal Courts for $40M (Posted 2 days ago)

Gilead says it will pay $40 million to resolve HIV drug lawsuits over Truvada, Atripla, Viread, Stribild and Complera pending in the federal court system, involving claims that the the company sat on safer formulations of the drugs for years to increase profits.