Photoaugmentation effects demonstrated in vitro

A number of sulphonamide-derived oral antidiabetics and diuretics were investigated for phototoxic properties, using different sources of light, by means of a photohemolysis test. Photohemolysis was obtained after irradiation with UVA, visible light and solar simulating irradiation. No phototoxic properties were seen when the test samples were exposed to UVB alone. The most prominent hemolysis was induced by solar simulating irradiation. When exposing the the test samples to UVB prior to the subsequently applied UVA, visible light or solar simulating irradiation, a significantly higher hemolysis was detected compared with the previous tests, suggesting photoaugmentation effects in this model.