More than Nail Deep: The Effect of Efinaconazole 10% Treatment on the Quality of Life in Patients with Onychomycosis: A post hoc Study

Efinaconazole 10% solution: a comprehensive review of its use in the treatment of onychomycosis

INTRODUCTION

Onychomycosis is an infection of the nail bed and the nail plate. While oral antifungals are first-line for moderate to severe onychomycosis, topical efinaconazole 10% solution (JUBLIA®; Clenafin®) is effective and safe for mild to moderate severity onychomycosis. It is FDA-approved for patients aged 6 years and above.

AREAS COVERED

This literature review includes pharmacokinetics, microbiology, efficacy, safety, and post-marketing surveillance. It demonstrates consistent safety and efficacy across diverse patient demographics and comorbidities, including pediatric, diabetic and the elderly populations, without systemic side effects or drug interactions.

EXPERT OPINION

Efinaconazole 10% solution is an important addition to the armamentarium of therapies available to treat onychomycosis. Certain subgroups respond particularly well: females versus males, children versus adults, early onset onychomycosis (<1-year disease), those with mild onychomycosis (≤25% nail involvement), absence of tinea pedis, and thin nail plates at baseline (<1 mm thickness). Efinaconazole 10% solution is effective in diabetics and has demonstrated efficacy against dermatophytomas. Efinaconazole may be a consideration when terbinafine resistance is a concern, due to its different target of action.

Efinaconazole in Onychomycosis

Onychomycosis is a fungal nail infection that causes nail discoloration, nail plate thickening, and onycholysis. Efinaconazole 10% topical solution is an FDA-approved treatment for onychomycosis patients aged 6 years and above. The drug functions as an antifungal by disrupting ergosterol synthesis in the fungal cell membrane. It exhibits higher in vitro activity against dermatophytes than other available antifungals such as ciclopirox and itraconazole, and the activity is comparable to amorolfine and terbinafine. Efinaconazole also provides enhanced nail penetration compared with other topical antifungals due to low surface tension, poor water solubility, and low keratin affinity. The pharmacokinetic studies suggest that the efinaconazole topical delivery to the nail bed is not markedly affected by the presence of disease. There is a subset of onychomycosis patients who are more likely to respond to efinaconazole 10% solution: female patients, those with lower BMI, mild onychomycosis, a short disease duration, no infected non-target toenails (large toenail disease only), and when concomitant tinea pedis is treated. Experts recommend efinaconazole 10% topical solution as the first line for mild-to-moderate onychomycosis, pediatric onychomycosis, those with liver or kidney disease, and as maintenance therapy to prevent relapse. The side effects of topical efinaconazole are minimal: most commonly ingrown toenails, dermatitis, vesicles, and pain at the application site. Altogether, phase I and phase III clinical trials, and post-hoc analyses indicate that efinaconazole 10% topical solution is a safe and effective treatment for adult and pediatric onychomycosis, with a satisfactory mycological and clinical cure.

Onychomycosis in Older Adults: Prevalence, Diagnosis, and Management

The risk of having onychomycosis increases with age. Data suggest that the prevalence of onychomycosis may be ≥ 20% in subjects aged ≥ 60 years and ≥ 50% in those aged ≥ 70 years. Older males are 2.1 times more prone to onychomycosis than are females. Although most nail dystrophies (approximately 50%) are caused by onychomycosis, proper clinical assessment followed by mycological examination is recommended to exclude other conditions such as nail trauma, lichen planus, and psoriasis. The US FDA-approved onychomycosis treatments are systemic antifungals (terbinafine and itraconazole) for severe onychomycosis and topical antifungals (ciclopirox 8%, efinaconazole 10%, and tavaborole 5%) for mild-to-moderate onychomycosis. Oral fluconazole is used off-label, and itraconazole may be considered for non-dermatophyte onychomycosis. Recently, fosravuconazole was approved in Japan for onychomycosis treatment. Although the treatment options and durations are the same for older patients as for other age groups, a clinical decision should take into account various age-related factors such as comorbidities, polypharmacy, hepatic and renal insufficiency, and noncompliance. Clinicians should also consider possible drug interactions and side effects when choosing a particular antifungal. Since the recurrence rate of onychomycosis is high, older patients should practice sanitization techniques, consider lifestyle changes, and perhaps consider using a topical antifungal as long-term maintenance therapy one to three times per week to prevent the recurrence of onychomycosis or to treat early disease.

One size does not fit all: the need for individualized treatment based on factors that may affect the therapeutic outcome of efinaconazole 10% solution for the treatment of toenail onychomycosis

Successful management of onychomycosis is a challenge because cure rates with most antifungals are relatively low and recurrence rates are high. A drug-based approach by treating the nail alone may not suffice. There are several host-related factors (age, sex, body mass index [BMI], and patient's quality of life), disease-related factors (disease severity, duration, and the number of toenails affected), and comorbidities (tinea pedis and diabetes) that may affect treatment efficacy. Here, we review the post hoc analyses of the phase III trials of efinaconazole 10% solution that have investigated the impact of these factors on topical therapy for toenail onychomycosis. The significant clinical variables that may affect the efficacy of efinaconazole include sex, BMI, disease severity, disease duration, and tinea pedis. As older patients may have slower toenail growth and more severe, longstanding disease compared with younger patients, they may require longer treatment duration, beyond the 48-week standard regimen. Treatment compliance may need to be discussed for an improved health outcome. Therefore, these prognostic factors need to be carefully evaluated, which may aid in formulating individualized therapy to maximize treatment success.