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.