Ciclopirox

Also known as: Penlac/Loprox (brands), hydroxypyridone antifungal

Dermatology

In plain English

Ciclopirox is an antifungal used as a medicated nail lacquer for fungal nail infections (and in other forms for skin fungal infections and dandruff). Applied to the nail, it works slowly over many months. It is best for mild-to-moderate nail infections that don't involve the nail root, and cure rates with topical treatment alone are modest.

The science

Ciclopirox is a broad-spectrum hydroxypyridone antifungal that chelates polyvalent metal cations (Fe3+, Al3+), disrupting metal-dependent fungal enzymes; it also has anti-inflammatory activity. For onychomycosis, an 8% nail lacquer is applied daily; a Cochrane review found ciclopirox lacquer more effective than vehicle for mycological and complete cure, though absolute cure rates are low, and newer hydroxypropyl-chitosan formulations improve nail penetration and cure rates.

References

• Bohn M / review of ciclopirox HPCH nail lacquer in onychomycosis, Drugs R D 2020
• Foley K et al., topical and device-based treatments for toenail onychomycosis, Cochrane Database Syst Rev 2020