Background: Anidulafungin is a cyclic lipopeptide antifungal agent of the echinocandin class. Members of this class of antifungal agents are known to inhibit the synthesis of glucan polymers in fungal cell walls. The spectrum of activity of anidulafungin includes Candida (all species, including strains resistant to fluconazole), Aspergillus, and Pneumocystis.