Naftifine Hydrochloride Gel 2%: An Effective Topical Treatment for Moccasin-Type Tinea Pedis

October 2015 | Volume 14 | Issue 10 | Original Article | 1138 | Copyright © October 2015

Linda F. Stein Gold MD,a Tracey Vlahovic DPM,b Amit Verma DrPH,c Babajide Olayinka MSc,c
Alan B. Fleischer Jr. MDc

a Henry Ford Health System, Detroit, MI
b Temple University School of Podiatric Medicine, Philadelphia, PA
c Merz North America, Inc., Raleigh, NC

BACKGROUND: Naftifine hydrochloride (naftifine) is a topical antifungal of the allylamine class, displaying fungicidal and fungistatic activity. Naftifine is generally used to treat interdigital tinea pedis; however, systemic therapy is often prescribed by healthcare providers for moccasin tinea pedis. Well-controlled clinical data on topical antifungal therapy for moccasin tinea pedis is limited.
OBJECTIVE: The objective of this analysis is to present data from two pooled randomized, vehicle-controlled studies that evaluated efficacy of once daily topical naftifine gel 2% and vehicle at end of treatment (week 2) and at 4 weeks post-treatment in subjects with moccasin tinea pedis.
METHODS: At visit 1, subjects were randomized to naftifine gel 2% or vehicle groups and subjects underwent baseline mycology culture, KOH, and symptom (erythema, scaling, and pruritus) severity grading. Naftifine gel 2% and vehicle treatment were applied once daily for 2 weeks and the subjects returned at weeks 2 and 6 for efficacy evaluation (mycology culture and grading of symptom severity). A total of 1174 subjects were enrolled with interdigital tinea pedis with or without moccasin infection. Of these subjects, 674 subjects had interdigital presentation while 500 subjects had moccasin infection in addition to the interdigital presentation. All 1174 subjects with interdigital presentation satisfied the inclusion criteria of a minimum of moderate erythema and scaling, and mild pruritus. Of the 500 subjects who had moccasin presentation, 380 satisfied the same inclusion criteria as mentioned above. Since data was analyzed as observed cases, between 337 and 349 subjects had data available for analysis of efficacy. Mycologic cure is defined as a negative dermatophyte culture and KOH, treatment effectiveness is defined as mycologic cure and symptom severity scores of 0 or 1, and complete cure is defined as mycologic cure and symptoms severity scores of 0.
RESULTS: At week 6, the cure rates in the naftifine arm vs. the vehicle were statistically higher (P<0.0001) for mycological cure rate (65.8% vs. 7.8%), treatment effectiveness (51.4% vs 4.4%), and complete cure rate (19.2% vs 0.9%).
CONCLUSION: Two weeks application of topical naftifine gel 2% is an effective monotherapy treatment for moccasin tinea pedis.

J Drugs Dermatol. 2015;14(10):1138-1144.


Skin fungal infections occur globally with the causative agents being dermatophytes, yeasts, and molds. Infection results from contact with infected humans, animals, soil, or fomites. Most skin infections are caused by dermatophytes which generally are acquired through contact with an infected person or by self-infection by transfer from another body part.1,2 Tinea pedis affects nearly 15% of the United States population, half of these display reoccurring outbreaks or relapse.2-5 Because of its frequency, tinea pedis ranks in the leading five diagnoses for visits to healthcare providers.6 and is one of the most commonly treated skin infections in the United States.2, 5 Those who may be at increased risk include those with diabetes, peripheral vascular disease, and immunodeficiencies.5
Trichophyton rubrum, Trichophyton mentagrophytes, and Epidermophyton floccosum are the three primary dermatophytes that have been isolated as the leading causes of tinea pedis. In the United States, Trichophyton rubrum alone is responsible for two-thirds of the cases.5
Interdigital tinea pedis is the most common form of the infection and is generally present in the interspace between the toes and has the potential to migrate to the underside of the toes. Moccasin tinea pedis is a more severe and chronic form of the infection, covering the sole, lateral, and plantar surfaces of the arch.5 A major differentiating characteristic of moccasin tinea pedis from interdigital is the presence of scale and hyperkeratosis, with mild erythema around the soles and side of the foot.5, 7, 8 In severe cases, secondary bacterial infections or inflammatory vesicles may manifest.2
Naftifine hydrochloride cream, 2% and Naftifine hydrochloride gel, 2% are both approved as once daily regimen for two weeks