Association between hydrochlorothiazide exposure and different incident skin, lip and oral cavity cancers: A series of population‐based nested case–control studies

UK population study found cumulative hydrochlorothiazide doses ≥50,000 mg were associated with an increased risk of squamous cell carcinoma, basal cell carcinoma and lip cancer (overall number needed to harm was 804, 2,463 and 200,000, respectively, but varied by age and sex).

SPS commentary:

This study provides further evidence suggesting a causal association between exposure to hydrochlorothiazide and nonmelanoma and lip cancers related to photosensitivity. The study authors note that for all cancer types, the absolute risk from cumulative hydrochlorothiazide exposure is much greater in those aged over 60 years with some evidence that absolute risk is also greater in men. 

The MHRA advises healthcare professionals to counsel patients taking hydrochlorothiazide-containing products of the cumulative, dose-dependent risk of non-melanoma skin cancer, particularly in long-term use, and the need to regularly check for (and report) any suspicious skin lesions or moles. Patients should also be advised to limit exposure to sunlight and UV rays and to use adequate sun protection.


British Journal of Clinical Pharmacology

Resource links:

MHRA guidance