Previously published retrospective analyses leading to the official warning about the use of hydrochlorothiazide (HCT).~The underlying pilot study examins, if the intake of HCT leads to increased dermal photosensitivity and in combination with UV-exposition to a DNA-damage of the skin.~Up until today, there is no prospective, randomized, placebo-controlled trial investigating the impact of HCT on dermal photosensitivity in greater detail. The pilot trial is designed as feasibility study to clarify the impact of HCT on dermal photosensitivity. This may facilitate evidence-based recommendations as to whether or not HCT increases the risk for skin cancer. Of note, HCT is one of most frequently prescribed drugs in Germany.
The clinical trial is designed as a national, prospective, single-center, double-blind, parallel group, randomized, controlled, interventional trial to investigate whether a therapy with HCT compared with placebo can affect dermal photosensitivity and DNA stability.