Butenafine is a topical antifungal used to treat tinea versicolor, tinea pedis, tinea cruris, and tinea corporis due to the fungi E. floccosum, T. mentagrophytes, T. rubrum, and T. tonsurans.The exact mechanism of action has not been established, but it is suggested that butenafine's antifungal activity is exerted through the alteration of cellular membranes, which results in increased membrane permeability, and growth inhibition. Butenafine is mainly active against dermatophytes and has superior fungicidal activity against this group of fungi when compared to that of terbinafine, naftifine, tolnaftate, clotrimazole, and bifonazole. It is also active against candida albicans, and it is more active than terbinafine. Butenafine works by inhibiting squalene monooxygenase which is an essential enzyme of Ergosterol biosynthesis. Butenafine is transported into the fungal cell vis diffusion. Squalene monooxygenase catalyzes the synthesis of (S)-2,3-epoxysqualene from squalene. Since it is inhibited, it cannot continue on to synthesize lanosterol which is essential in the synthesis of ergosterol. Without ergosterol in the cell membrane, the cell membrane sees increased permeability which allows intracellular components to leak out of the cell. Ergosterol is also essential in cell membrane integrity so without that, eventually the cell collapses and dies.. The fungal cell also cannot synthesize new cell membranes for new fungus cells if there is no ergosterol. The inhibition of squalene monooxygenase also causes a buildup of squalene which is toxic to the fungal cell.

Butenafine Pathway References