Optimal use of existing and new antifungal drugs.

Clinicians are increasingly aware that fungal pathogens are a significant cause of morbidity and mortality in hospitalized patients. Historically, these infections occurred in severely immunocompromised patients who were undergoing treatment for hematological malignancy or solid organ transplantation. Currently, however, systemic fungal infections are commonly seen in debilitated patients who are being nursed in intensive care or high-dependency units. These infections are mostly caused by Candida albicans but there is a growing proportion of strains of non- albicans Candida spp, some with reduced susceptibility to commonly used antifungals. The limited armamentarium of antifungal agents to date has meant that amphotericin B continues to be considered the most effective therapeutic agent albeit with a poor record of treatment-limiting side effects. The past decade has seen some encouraging developments in antifungal therapy. Three lipid formulations of amphotericin B showing reduced toxicity compared with the desoxycholate formulation are now licensed. There are three investigational triazoles currently undergoing evaluation that should prove important additions to existing members of this class. The echinocandin caspofungin is the first of a new class of antifungal agents with a novel mode of action, which has recently been approved for use in the United States.