Binafin is an allylamine with a range of antifungal activity. It is fungicidal against dermatophytes, moulds and certain dimorphic fungi. Binafin is either fungicidal or fungistatic against yeasts, depending on the species. Binafin interferes with fungal ergosterol biosynthesis by inhibiting squalene epoxidase in the fungal cell membrane at an early stage. This leads to a deficiency in ergosterol and to intracellular accumulation of squalene, resulting in fungal cell death. Binafin is highly effective in fungal infections of the skin, hair and nails caused by Trichophyton spp., Microsporum spp. and Epidermophyton floccosum. It is also effective against yeast infections of the skin, principally those caused by the genus candida. Topical terbinafine appears to be effective in pityriasis versicolor due to Pityrosporum arbiculare.