Characteristics and Efficacy of Two Topical Therapeutic Agents for Onychomycosis

Tinea pedis and tinea unguium are the most common dermatophytoses seen in the daily practice of dermatology. According to a report in Japan Foot Week 2006, it is estimated that about 1 in 5 Japanese have tinea pedis and that about 1 in 10 have tinea unguium. Thus far, use of oral antifungal agents has been the first-line therapy for onychomycosis. Many patients with onychomycosis, however, are elderly and have concomitant diseases as well as liver function disorder. Moreover, oral medications are reportedly associated with risks of impaired liver function and interactions. Due to such risks, therefore, treatment with topical agents is the only applicable therapy for most patients with onychomycosis. Recently, two topical agents (efinaconazole in 2014 and luliconazole in 2016) have been approved for the treatment of onychomycosis in Japan. Efinaconazole 10% solution is a triazole antifungal drug developed in Japan. Due to its low keratin affinity, efinaconazole shows high transungual penetration into nails and retains a high antifungal activity in the nail plate and the nail bed. Luliconazole 5% solution is an imidazole antifungal agent that has high keratin affinity. Luliconazole has also been shown in vitro to permeate from the superficial to the deep layers of the nail and to achieve concentrations above the MIC in all layers of the nail. Both efinaconazole 10% solution and luliconazole 5% solution have high antifungal activities for Trichophyton species. These two topical agents, therefore, have certainly increased treatment options for onychomycosis in the daily practice of dermatology.