Echinocandins--new antifungal agents.

Over the past 10-15 years, the number of clinically available antifungal agents has increased substantially, due to rise in the number of invasive fungal infections, which are a real problem for specialists. Echinocandins are the new class of antifungal agents available for clinical use. This class comprises over 20 natural echinocandins and several semisynthetic ones. Natural echinocandins are not of clinical utility due to their toxicity and low water-solubility (which does not allow obtaining parenteral pharmaceutical forms), although they have good antifungal activity against Candida species. Consequently, semisynthetic echinocandins with minimal toxicity, good antifungal activity and high water-solubility were obtained. All echinocandins inhibit beta-1,3-glucan-synthase, an essential component of the fungal cell wall. Echinocandins exhibit potent antifungal activity against key pathogenic fungi, including Candida species, Aspergillus species and Pneumocystis carinii. The available echinocandins lack in vitro activity against Cryptococcus neoformans. The semisynthetic echinocandins have great advantages, among which low toxicity, fast antifungal activity, favorable pharmacokinetics that allow once-daily administration. The echinocandins recently available for clinical use are: caspofungin, micafungin and anidulafungin.