One of the antifungal drugs. Terbinafine (Lamisil) is used to treat fungus infections of the scalp (ringworm), body, groin (called jock itch), feet (athlete’s foot), fingernails, and toenails. As a cream, Terbinafine is spread on the skin to prevent the fungus from growing. It is taken as a tablet to treat infections of the nails and hair follicles.