How does it work? Clotrimazole, which is an antifungal medicine used to treat infections with fungi and yeasts. mechanism: Clotrimazole kills fungi and yeasts by interfering with their cell membranes. It works by stopping the fungi from producing a substance called ergosterol, which is an essential component of fungal cell membranes. The disruption in production of ergosterol causes holes to appear in the fungal cell membrane. What is it used for? Skin infections caused by yeasts (eg Candida), dermatophytes (eg Trichophyton, Tinea), moulds and other fungi, such as the following: Athlete's foot (tinea pedis). Fungal infection of the groin, ie jock itch (tinea cruris). Ringworm (tinea corporis). Fungal nappy rash caused by infection with Candida albicans. Sweat rash caused by infection with Candida albicans. Relieving the external symptoms (candidal vulvitis) of vaginal thrush (candidal vaginitis).