Pharmacotherapy for onychomycosis: new and emerging treatments

ABSTRACT

Introduction: Onychomycosis is the most common nail disorder seen in clinical practice. It is not merely an aesthetic disorder and may cause significant disability and affect the quality of life. There are no strict guidelines for onychomycosis therapy. Therefore, medical management is individualized based on drug efficacy, taken together with clinical presentation, infecting organism, co-morbidities, concomitant medications, and patient preferences.

Areas covered: This review provides a clinically oriented critical perspective on the pathophysiology of onychomycosis, infecting organisms, and prognostic factors, and how these play a role in choosing optimal pharmacotherapy. Clinical and pharmacological considerations are described in explaining the optimal medical management of onychomycosis.

Expert opinion: Onychomycosis is a common nail disorder with significant burden; yet, there are only six Food and Drug Administration approved medical therapies for this indication. When therapy is applied to specific patients, the options become even more limited. In addition, mycological and complete cure rates of systemic medications have not yet approached 100%, and cure rates for topicals are much lower. Further insight into the pathophysiology of the disease focusing on the fungal life cycle and understanding biofilms will likely lead to more optimal cure rates, decreasing morbidity and enhancing the overall quality life of the affected individuals.

KEYWORDS:

• Onychomycosis
• fungal nail infection
• tinea pedis
• pharmacotherapy
• complete cure
• mycological cure
• clinical cure
• terbinafine
• itraconazole
• fluconazole; ciclopirox; efinaconazole; tavaborole

Article highlights

• Onychomycosis is the most common nail disorder, which is not only a cosmetic concern, but is associated with pain, morbidity, and decreased the quality of life.

• The pathophysiology of onychomycosis has not been fully elucidated. Since the nail unit lacks cell-mediated immunity, it is susceptible to infections by dermatophytes, NDMs, and yeasts.

• The diagnosis of onychomycosis is based on physical examination findings, as well as, confirmatory laboratory tests.

• Oral FDA approved onychomycosis therapies include terbinafine, itraconazole, and griseofulvin. Griseofulvin is rarely used. Fluconazole is commonly used off-label. Terbinafine may be preferred as pharmacotherapy due to relatively good cure rates and limited drug–drug interactions. Oral therapies generally have shorter regimens and better cure rates than topical therapies.

• Topical FDA approved therapies include ciclopirox 8% nail lacquer, efinaconazole 10% solution and tavaborole 5% solution. The treatment regimens for these newer therapies are generally easier for patients to follow and cure rates are higher compared to ciclopirox.

• Mycological and complete cure rates approaching 100% have been elusive. Pharmacotherapy that better exploits the fungal life cycle and biofilms may lead to better cure rates.

• Recurrences are common following onychomycosis therapy. More research is needed to determine optimal regimens for prevention of recurrence.

This box summarizes key points contained in the article.

Declaration of interest

S Lipner has received grants for clinical trials from MOE Medical Devices and has served as a consultant for Bako Diagnostics. They have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

Reviewer disclosures

One referee has served on the speaker's bureau of Orthodermatologics. Another referee has received research funding, speaking and/or consulting support from companies including Galderma, GlaxoSmithKline/Stiefel, Almirall, Leo Pharma, BMS, Boehringer Ingelheim, Mylan, Celgene, Pfizer, Ortho Dermatology, AbbVie, Samsung, Janssen, Lilly, Menlo, Merck, Novartis, Regeneron, Sanofi, Novan, Qurient, National Biological Corporation, Caremark, Advance Medical, Sun Pharma, Suncare Research, Informa, UpToDate and National Psoriasis Foundation.

Additional information

Funding

This manuscript has not been funded.