Terbinafine is an oral anti-fungal agent used to treat onychomycosis, which is a fungal infection of the nails. Oral terbinafine has been demonstrated to be the most effective treatment for the mycological cure of toenail fungal infections. Terbinafine works by inhibiting squalene epoxidase, the enzyme in fungal cells that convert squalene to squalene epoxide. This results in an intracellular accumulation of squalene and results in fungal cell death. 

Ciclopirox nail lacquer is a topical antifungal treatment for mild to moderate onychomycosis (i.e. fungus of the fingernails and toenails) involving ≤50% of the nail.