FDA Updates Hydrochlorothiazide Label to Include Nonmelanoma Skin Cancer Risk

Jake Remaly

August 24, 2020

Hydrochlorothiazide (HCTZ) is associated with an increased risk of nonmelanoma skin cancer, and patients who take the drug should limit sun exposure and undergo regular skin cancer screening, according to updates to the medication’s label.

The skin cancer risk is small, however, and patients should continue taking HCTZ, a commonly used diuretic and antihypertensive drug, unless their doctor says otherwise, according to a U.S. Food and Drug Administration announcement about the labeling changes, which the agency approved on Aug. 20.

HCTZ, first approved in 1959, is associated with photosensitivity. Researchers identified a relationship between HCTZ and nonmelanoma skin cancer in postmarketing studies. Investigators have described dose-response patterns for basal cell carcinoma and squamous cell carcinoma (SCC).

An FDA analysis found that the risk mostly was increased for SCC. The drug was associated with approximately one additional case of SCC per 16,000 patients per year. For white patients who received a cumulative dose of 50,000 mg or more, the risk was greater. In this patient population, HCTZ was associated with about one additional case of SCC per 6,700 patients per year, according to the label.

Reliably estimating the frequency of nonmelanoma skin cancer and establishing a causal relationship to drug exposure is not possible with the available postmarketing data, the label notes

"Treatment for nonmelanoma skin cancer is typically local and successful, with very low rates of death," the FDA said. "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 nonmelanoma skin cancer, unless directed otherwise from their health care provider."

Patients can reduce sun exposure by using broad-spectrum sunscreens with a sun protection factor value of at least 15, limiting time in the sun, and wearing protective clothing, the agency advised.

This article originally appeared on MDedge.com, part of the Medscape Professional Network.


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