Penlac (generic: ciclopirox) is a prescription medication used to treat fungal infections of the fingernails and toenails. Penlac belongs to a group of drugs called antifungals, which work by stopping the growth of fungus.

This medication comes in topical solution form and is applied to the affected nail once daily, at night or 8 hours before washing. Avoid contact with eyes and mucous membranes.