Efficacy and safety of a new single-dose terbinafine 1% formulation in patients with tinea pedis (athlete's foot): a randomized, double-blind, placebo-controlled study

Therapy of Skin, Hair and Nail Fungal Infections

Treatment of superficial fungal infections has come a long way. This has, in part, been through the development and evaluation of new drugs. However, utilising new strategies, such as identifying variation between different species in responsiveness, e.g., in tinea capitis, as well as seeking better ways of ensuring adequate concentrations of drug in the skin or nail, and combining different treatment methods, have played equally important roles in ensuring steady improvements in the results of treatment. Yet there are still areas where we look for improvement, such as better remission and cure rates in fungal nail disease, and the development of effective community treatment programmes to address endemic scalp ringworm.

Mycology - an update Part 3: Dermatomycoses: topical and systemic therapy

Treatment of dermatophyte infections is based on the clinical picture and mycological detection of the causative pathogen. Based on the appropriate indication, onychomycosis can be treated topically using an antimycotic nail lacquer. Atraumatic nail abrasion with 40 % urea ointment has a beneficial effect on healing. Continuous treatment of onychomycosis with terbinafine represents the most effective systemic therapy. Terbinafine or itraconazole are the safest and most effective antimycotic agents for the treatment of onychomycosis in children. For laser therapy of onychomycosis, only a few studies on clinical efficacy are available. Regarding tinea capitis, targeted species-specific therapy of dermatophytosis of the scalp is currently recommended. Terbinafine, yet also itraconazole and fluconazole, are effective in tinea capitis caused by Trichophyton species. Microsporum infections of the scalp are preferably treated with griseofulvin, alternatively with itraconazole or fluconazole. Terbinafine is less effective. Candidal intertrigo are topically treated with nystatin, but azoles or ciclopirox olamine are also suitable candidates. Systemically, fluconazole or itraconazole are used. Topical and systemic antimycotics are equivalent forms of therapy in acute vulvovaginal mycosis. Fluconazole is the drug of choice in chronic recurrent vulvovaginal mycosis caused by Candida albicans. Ketoconazole shows very good efficacy in tinea versicolor. With respect to systemic treatment of severe and widespread tinea versicolor, itraconazole is the drug of choice.

Formulation design for topical drug and nanoparticle treatment of skin disease

The skin has evolved to resist the penetration of foreign substances and particles. Topical therapeutic and cosmeceutical delivery is a growing field founded on selectively overcoming this barrier. Both the biology of the skin and the nature of the formulation/active ingredient must be aligned for efficient transcutaneous delivery. This review discusses the biological changes in the skin barrier that occur with common dermatological conditions. This context is the foundation for the discussion of formulation strategies to improve penetration profiles of common active ingredients in dermatology. Finally, we compare and contrast those approaches to recent advances described in the research literature with an eye toward the future of topical formulation design.

Efficacy and safety of 1 % terbinafine film-forming solution in Chinese patients with tinea pedis: a randomized, double-blind, placebo-controlled, multicenter, parallel-group study

Background and objectives

Superficial fungal skin infections are treated using topical antifungals. The aim of this study was to demonstrate the efficacy of a single application of 1 % terbinafine film-forming solution (FFS) versus placebo for the treatment of tinea pedis in the Chinese population.

Methods

Six centers in China randomized 290 patients in a 1:1 ratio to receive either 1 % terbinafine FFS or FFS vehicle (placebo) once on the affected foot/feet. Efficacy assessments included microscopy and mycologic culture, and assessing clinical signs and symptoms at baseline, and at weeks 1 and 6 after the topical treatment. All adverse events were recorded.

Results

At week 6, 1 % terbinafine FFS was superior to placebo for effective treatment rate (63 vs. 8 %); clinical cure (30 vs. 6 %); mycological cure (86 vs. 12 %); negative microscopy (90 vs. 24 %); and negative mycological culture (90 vs. 27 %): all p ≤ 0.001 and clinically relevant. At week 6, 1 % terbinafine FFS was clinically superior to placebo for the absence of: erythema (69 vs. 29 %); desquamation (33 vs. 8 %); and pruritus (70 vs. 30 %): all p ≤ 0.001 and clinically relevant. At week 6, differences in the average total signs and symptoms scores were significantly lower for 1 % terbinafine FFS versus placebo (p ≤ 0.001). Both 1 % terbinafine FFS and placebo were safe and well tolerated based on adverse events and investigator and patient assessments.

Conclusions

This double-blind, randomized, multicenter study demonstrated one single topical application of 1 % terbinafine FFS was safe and effective in the treatment of tinea pedis in the Chinese population.

Efficacy, tolerability and consumer acceptability of terbinafine topical spray versus terbinafine topical solution: a phase IIa, randomised, observer-blind, comparative study

INTRODUCTION

Tinea pedis is one of the world's most prevalent dermatophyte infections. MedSpray™ tinea pedis 1 % w/w (topical spray) is a novel, easy-to-use propellant-based spray formulation containing 1 % w/w terbinafine, requiring no manipulation at the site of infection. This is in contrast to the only formulation currently approved in Europe for single application (none are approved in the USA for single use), which is Lamisil(®) Once 1 % w/w (topical solution), containing 1 % w/w terbinafine hydrochloride, which requires manipulation on the affected area.

OBJECTIVE

The aim of this study was to evaluate the efficacy, tolerability and consumer acceptability of a topical spray versus a topical solution in the treatment of tinea pedis.

METHODS

This study is a phase IIa, randomised, observer-blind, non-inferiority comparative study of the topical spray compared with the topical solution over a 12-week study period. The study was conducted at Bioskin GmbH, Hamburg and Berlin. Patients (n = 120) who presented with the presence of interdigital tinea pedis caused by dermatophytes on one or both feet were enrolled in the study. Patients were randomly assigned between the two treatment groups. Either the topical spray or the topical solution was administered by the study nurse and consisted of a single application (equivalent to 20 mg of terbinafine per foot) on day 1 of the study. No further applications were made for the duration of the study. The hypothesis formulated before commencement of the study was that the topical spray would prove to be non-inferior to the topical solution. Efficacy assessments, including clinical signs and symptoms, mycology and microscopy were performed at baseline and 1, 6 and 12 weeks after treatment.

RESULTS

The rate of mycological cure at week 1 was statistically equivalent for both treatments. There was a significant reduction in the overall clinical score as assessed by the Physician's Global Assessment of signs and symptoms for both treatment groups.

CONCLUSION

The topical spray and the topical solution showed comparable anti-fungal activity. Furthermore, the non-inferiority of topical spray to the topical solution was confirmed as determined by the proportion of patients categorised as successfully treated at week 1. This confirms that a topical spray product, which can be applied once without touching the affected skin, is equally as effective in the treatment of tinea pedis and removes the risk of organism transfer associated with touching infected areas.

CLINICAL TRIAL REGISTRATION NUMBER

EudraCT-No. 2008-002399-92.

Two antifungal components isolated from Fructus Psoraleae and Folium Eucalypti Globuli by bioassay-guided purification

Fructus Psoraleae and Folium Eucalypti Globuli have long been used as Chinese medicines to treat various ailments such as asthma, eczema and dermatomycosis. In previous studies, their antifungal activities were demonstrated. The aim of the present study was to isolate active antidermatophytic compounds from their ethanolic extracts by means of bioassay-guided purification. Guided by the inhibitory activities on Trichophyton mentagrophytes, Trichophyton rubrum and Paecilomyces variotii, bakuchiol was isolated from the n-hexane fraction of Fructus Psoraleae whilst macrocarpal C was isolated from the n-hexane fraction of Folium Eucalypti Globuli. Both pure compounds could effectively inhibit the growth of dermatophytes in vitro. This is the first paper to report the isolation and identification of active antidermatophytic compounds from Fructus Psoraleae and Folium Eucalypti Globuli by the bioassay-guided purification.

Update on terbinafine with a focus on dermatophytoses

Since terbinafine was introduced on the world market 17 years ago, it has become the leading antifungal for the treatment of superficial fungal infections, aided by unique pharmacologic and microbiologic profiles. This article reviews mode of action, antimycotic spectrum and disposition profile of terbinafine. It examines the data, accumulated over 15 years, on the comparative efficacy of terbinafine (vs griseofulvin, itraconazole, fluconazole) in the management of the infections for which it is primarily indicated (eg, dermatophytoses) and provides a brief discussion on its use for the treatment of non-dermatophyte infections. Finally, the available data on the newest topical and systemic formulations are introduced.

[Topical terbinafine. Reduction of duration of therapy for tinea pedis]

Superficial fungal infections are common and worldwide in distribution. Latest estimates suggest one- third of the population in Europe has a fungal infection of their feet, with dermatophyte infections of the skin of the feet (tinea pedis) most common. Tinea pedis interdigitalis is by far most common and can be effectively treated topically. Common agents include azoles, hydroxypyridones and allylamines, with morpholines used less frequently. While most antifungals have mainly fungistatic effects on dermatophytes, the causative agents of tinea pedis, terbinafine--an allylamine--is fungicidal. Due to this feature shorter treatment periods are possible using topical terbinafine. For effective treatment of uncomplicated tinea pedis interdigitalis, azole cream preparations are often used twice daily for four weeks whereas 1% terbinafine cream can be applied once a day for one week. Since 2006, 1% terbinafine is also available as a film-forming solution (FFS), which makes single-dose treatment possible. FFS may prove superior in daily practice with increased compliance and thus reduced recurrences.

Comparable efficacy and safety of various topical formulations of terbinafine in tinea pedis irrespective of the treatment regimen: results of a meta-analysis

BACKGROUND

Terbinafine has been widely used with major success as a topical antifungal therapy for tinea pedis (athlete's foot). Its efficacy and safety have been validated in several clinical trials, which have demonstrated clinical efficacy for the drug after only 1 week of treatment when applied once daily, a reflection of the high fungicidal potency of the drug and its ability to form a depot in the upper skin layer. To improve patients' compliance further, a terbinafine-containing film-forming solution has been developed for single-dose therapy of athlete's foot. This novel formulation delivers terbinafine in high amounts and for a prolonged period of time into the skin, making one-shot treatment feasible. Over the past years there have been a variety of trials evaluating use of topical terbinafine addressing different pharmaceutical formulations, treatment durations, and application frequencies, but a detailed meta-analysis of these trials has not been conducted to date.

OBJECTIVE

The present study is the first meta-analytic evaluation of the available data on the efficacy (clinical and mycologic cure rates) and safety (adverse events) of all topical forms of terbinafine for the treatment of tinea pedis.

METHODS

An international, systematic literature search of 12 electronic databases (including MEDLINE, EMBASE, and Cochrane databases) using a pre-specified search strategy was conducted in March 2006. This meta-analysis included only randomized controlled trials in which terbinafine had been used for topical treatment of tinea pedis in comparison with placebo or an active control. Studies of all available topical formulations of terbinafine, frequencies of application, and durations of treatment were included.

RESULTS

Of 100 identified articles published between 1990 and 2006, 19 met the criteria for analysis. These 19 studies involved 2899 patients with clinical and mycologic diagnoses of tinea pedis (nine placebo-controlled trials and ten active-controlled trials). Efficacy analysis demonstrated that the mycologic cure rate was significantly superior with terbinafine compared with placebo (relative risk [RR] 3.17; p < 0.001). No significant differences in efficacy were found amongst different formulations of terbinafine, treatment durations, or frequencies of application. Comparable results were obtained with respect to clinical cure rate for terbinafine compared with placebo (RR 2.75; p < 0.001). Comparison of the efficacy of terbinafine versus active control indicated a nonsignificant difference in favor of terbinafine with regard to mycologic cure rate (RR 1.03; p = 0.423) and clinical cure rate (RR 1.09; p = 0.11). The median duration of treatment was also shorter with terbinafine (1 week) compared with active controls (2 weeks). Analysis of the placebo-controlled studies showed that there was no significant difference in the risk of adverse events with terbinafine compared with placebo (RR 1.34; p = 0.34). Likewise, no significant differences in adverse events were found between terbinafine and active controls (RR 1.08; p = 0.72).

CONCLUSION

Terbinafine is very well tolerated in any topical pharmaceutical formulation and also has high efficacy as a cure for tinea pedis, irrespective of type of pharmaceutical formulation, treatment duration, and frequency of application, including the recently established one-shot regimen. In addition, terbinafine has an apparently unique advantage over other antifungal agents with respect to the required duration of treatment for tinea pedis.