Phototoxicity and photocarcinogenesis associated with voriconazole.

The antifungal voriconazole was given its marketing authorization in 2002. Several kinds of adverse effects have been reported, including acute and chronic cutaneous adverse effects, mainly due to a phototoxicity mechanism. More recently, some authors have reported that voriconazole was involved in the occurrence of multiple and often-aggressive cutaneous squamous cell carcinomas if the treatment was maintained for a long time. According to safety data in studies assessing voriconazole effectiveness, 8% of outpatients may experience phototoxic events. An overview of the different types of phototoxicity and of the concerned population was given by the 61 published case reports of photo-induced voriconazole-related skin adverse events (including 18 cases of squamous cell carcinomas). The most likely mechanisms may be phototoxicity directly related to either voriconazole or to its N-oxide main metabolite, and an interaction with retinoid metabolism; moreover, immunodeficiency may enhance the risk of skin cancer. Several issues remain to be investigated, and studies are needed concerning the phototoxicity and photocarcinogenesis of voriconazole and the prognosis of chronic non-malignant skin lesions. Voriconazole prescription must be associated with strict photoprotection; in case of a phototoxic adverse event, another azole may be recommended.