[8/20/2020] The U.S. Food and Drug Administration has approved changes to the hydrochlorothiazide (HCTZ) drug label to inform health care professionals and patients about a small increased risk of non-melanoma skin cancer (basal cell skin cancer or squamous cell skin cancer) associated with HCTZ use and to encourage patients to protect their skin from the sun. Hydrochlorothiazide is a diuretic used to treat high blood pressure and other conditions.
Specifically, the labeling changes include the following:
- Adverse Reactions, Postmarketing Experience: information has been added about an increased risk of non-melanoma skin cancer associated with HCTZ.
- Patient Counseling Information: information has been added instructing patients to protect their skin from the sun and undergo regular skin cancer screenings.
The overall risk for non-melanoma skin cancer increases as individuals age and as they spend more time in the sun. The increased risk of developing non-melanoma skin cancer while taking HCTZ, a drug associated with photosensitivity (increased sensitivity to sunlight), is small.
An FDA Sentinel Initiative study found that the increased risk was mostly for squamous cell carcinoma (SCC). In the overall study population, the increased risk for SCC in patients on HCTZ was approximately one additional case per 16,000 patients per year.
In addition, treatment for non-melanoma skin cancer is typically local and successful, with very low rates of death. Meanwhile, the risks of uncontrolled blood pressure can be severe and include life-threatening heart attacks or stroke. Given this information, patients should continue to use HCTZ and take protective skin care measures to reduce their risk of non-melanoma skin cancer, unless directed otherwise from their health care provider.
Measures for restricting sun exposure include using broad spectrum sunscreens with a sun protection factor value of at least 15, reapplying sunscreen regularly, and limiting time in the sun. Protective clothing, sunglasses and broad-brimmed hats are other ways to avoid sun exposure. See the FDA website for more information about sun protection and sunscreens.