Voriconazole does not Potentiate Photo Damage from UVB Exposure

Voriconazole is an effective anti-fungal triazole commonly used in bone marrow and solid organ transplant recipients. However, reports of accelerated development of aggressive squamous cell carcinomas in immunocompromised patients are documented following voriconazole use. It is hypothesized that voriconazole or its primary N-oxide metabolite, voricinazole-N-oxide increases keratinocyte susceptibility via UV-mediated cell damage. We aimed to investigate whether voriconazole or voriconazole-N-oxide potentiate cell death after UVB irradiation in vitro. Both compounds absorb UVB but voriconazole exhibited weak emission while voriconazole-N-oxide showed no detectable emission in UVA. Exposure of different skin cell lines to these compounds did not show significant reduction in cell survival and regardless whether the cells were exposed to the drugs before or after UVB irradiation. However, in primary human keratinocytes, both drugs caused a small increase in cell survival following drug incubation and UVB irradiation. This is the first report documenting the effect of voriconazole and voriconazole-N-oxide in relation to UVBassociated cell death in vitro.