Imidazole-derivative azole antifungal. Usually fungistatic. May be fungicidal at high concentrations against very susceptible organisms. Alters cellular membranes, resulting in increased membrane permeability, secondary metabolic effects, and growth inhibition. Fungistatic activity may result from interference with ergosterol synthesis. Active in vitro against dermatophytes such as Epidermophyton floccosum, Microsporum audouinii, M. canis, M. gypseum, Trichophyton mentagrophytes, T. rubrum, T. tonsurans, and T. violaceum. Active in vitro against yeasts such as Candida albicans, C. glabrata (formerly Torulopsis glabrata), C. guilliermondii, C. krusei, C. parapsilosis, C. pseudotropicalis, and C. tropicalis. Active in vitro against other fungi such as Malassezia furfur (Pityrosporum orbiculare or P. ovale), Aspergillus, Blastomyces dermatitidis, Cryptococcus neoformans, Histoplasma capsulatum, and Paracoccidioides brasiliensis. Active in vitro against some Gram-positive bacteria such as Bacillus subtilis, Clostridium perfringens, C. tetani, C. botulinum, Enterococcus faecalis, Erysipelothrix rhusiopathiae, Micrococcus luteus, Propionibacterium acnes, Staphylococcus aureus, S. epidermidis, and S. saprophyticus. Cross-resistance can occur among azole antifungals. Some C. albicans isolates from patients undergoing long-term azole antifungal therapy show decreased in vitro susceptibility to sulconazole and other imidazole-derivative antifungals as well as to triazole derivatives.