Two recent case studies in a Danish population have found an increased risk of non-melanoma skin cancer associated with use of Hydrochlorothiazide. This risk increases with cumulative dose. The increased risk is associated with non-melanoma skin cancer – basal cell carcinoma, squamous cell carcinoma and squamous cell carcinoma of the lip.
The exact mechanism is unknown, but Hydrochlorothiazide is known to sometimes cause photosensitising effects of the skin and make it more sensitive to ultraviolet light.
The same studies have found no significant risk with other blood pressure medicines.
Products containing Hydrochlorothiazide
These include Moduretic, Hydrochlorothiazide, Accuretic and Cilazapril.
Advice for consumers
DO NOT STOP TAKING a hydrochlorothiazide containing medicine unless instructed to by your general practitioner. The benefit of treating high blood pressure outweighs the small possible increased risk of developing non-melanoma skin cancer.
Patients who are at high risk of developing non-melanoma skin cancer should use adequate sun protection in any case. It is important to continue to monitor your skin for any new growths or changes which may indicate possible non-melanoma skin cancer.
Check your skin and lips regularly for lumps and bumps and if you notice any change consult your doctor or your dermatologist.
The risk does appear to be low and incurs over a long period of time.
There appears to be a small link between high blood pressure drugs containing Hydrochlorothiazide and an increased risk of non-melanoma skin cancer. These risks are very small and patients should not stop taking their blood pressure medications without first consulting their general practitioner.
Patients at high risk of non-melanoma skin cancer should discuss this with their general practitioner and if appropriate other blood pressure treatments may be an option.
Sun protection is very important to prevent skin cancer. Regular self-monitoring and monitoring from GP’s and dermatologists is also important in patients at risk.