Evaluation of Drug-Associated Phototoxicity Under 980 nm Near-Infrared Laser Irradiation in Human Dermal Fibroblasts

Background: Many widely used drugs—including non-steroidal anti-inflammatory drugs, tetracyclines and thiazide diuretics—are labelled as photosensitising, yet their phototoxicity has been defined almost entirely by ultraviolet A (UVA) exposure. Whether this risk extends to the near-infrared (NIR) wavelengths of lasers commonly used in aesthetic medicine is unclear, and a history of such medication is often treated as a relative contraindication to laser procedures. Methods: A bibliometric analysis of 391 Scopus-indexed publications using VOSviewer was performed to quantitatively map the thematic structure of the retrieved literature. The bibliometric mapping was complemented by sequential refinement of the Scopus corpus and a focused assessment of the final records to determine whether studies directly addressing the predefined experimental question could be identified. We assessed whether 980 nm diode-laser irradiation of normal human dermal fibroblasts (HDFs) induces phototoxicity in the presence of seven photosensitisers (ketoprofen, meloxicam, hydrochlorothiazide, doxycycline and diclofenac, with chlorpromazine and 8-methoxypsoralen as reference photosensitizers). Cells were irradiated through the closed culture-plate lid at two fluences (62.3 and 34.4 mJ/cm and viability was measured 0.5, 1 and 24 h later. Data were analysed by two-way ANOVA (compound × laser), pairwise Welch tests with Benjamini–Hochberg correction, and equivalence testing against an ISO 10993-5-based margin. Results: Viability remained between 82.7% and 109.6% of control under all conditions and never fell below the 70% cytotoxicity threshold. The compound × laser interaction was non-significant at every time point (p = 0.25–0.69), indicating no drug-specific phototoxicity, and no pairwise comparison remained significant after correction. A small, drug- and fluence-independent reduction of about six percentage points was observed but stayed well within the non-cytotoxic range and was equally present in drug-free controls. Conclusions: Under the specific 980 nm irradiation conditions tested, the photosensitising drugs did not increase phototoxicity in normal human dermal fibroblasts. These findings support a wavelength-specific view of drug photosafety: rigorous UVA-directed photoprotection remains essential, whereas the tested drugs did not increase phototoxicity under the specific in vitro 980 nm irradiation conditions evaluated in this study.