Mechanism of action unknown. Presumably inhibits ergosterol synthesis, and so alters cellular membranes, resulting in increased membrane permeability, secondary metabolic effects, and growth inhibition. Usually fungistatic. May be fungicidal at high concentrations or against very susceptible organisms. 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 candida such as Candida albicans, C. glabrata (Torulopsis glabrata), C. guilliermondii, C. krusei, C. parapsilosis, and C. tropicalis; against other fungi such as Malassezia furfur (Pityrosporum orbiculare). Active in vitro against Aspergillus flavus, A. fumigatus, A. nidulans, A. niger, Cryptococcus neoformans, Epidermophyton floccosum, Exophiala werneckii, Petriellidium boydii, and Sporothrix schenkii, also against bacteria such as Actinomadura madurae, Corynebacterium minutissimum, Nocardia asteroides, N. brasiliensis, and Streptomyces somaliensis. Cross-resistance can occur among azole antifungals. Some C. albicans resistant to ketoconazole show cross-resistance to oxiconazole and other imidazole-derivative antifungals as well as to triazole derivatives. Some strains of M. furfur (Pityrosporum orbiculare) resistant to oxiconazole in vitro are cross-resistant to econazole.