The echinocandins, first novel class of antifungals in two decades: Will they live up to their promise?

The echinocandins comprise a major development in systemic antifungal thera py. They rapidly and irreversibly inhibit glucan synthesis in the fungal ce ll wall, a distinct target from azole antifungals, flucytosine and polyenes . As such, the echinocandins appear effective against triazole and amphoter icin B resistant fungi. The spectrum is still not fully understood because of problems with susceptibility testing, and because of limited studies in animal models. The primary target species for clinical studies include Cand ida and Aspergillus, but the class is likely to have broader use. Lack of n ephrotoxicity and few drug interactions make this class attractive. The maj or limitations at present appear to be the lack of oral formulation and unc ertainty regarding the extent of the spectrum. These drugs have the potenti al of being significant additions to the management of mycoses in the criti cally ill patient.