Usefulness and pharmacokinetic study of oral terbinafine for hyperkeratotic type tinea pedis

Abstract

SummaryTo study and establish an optimal administration method of oral antifungal, terbinafine (TBF), for hyperkeratotic type tinea pedis, from the pharmacokinetic point of view, 20 patients with hyperkeratotic type tinea pedis were given TBF 125 mg once daily for 4 weeks and observed over time for improvement in dermatological symptoms and mycological efficacy. Targeting five of the patients, TBF concentration in the stratum corneum was measured using the liquid chromatography ⁄ tandem mass spectrometry (LC-MS ⁄ MS) method. TBF was detected in the stratum corneum of the sole 1 week after beginning the treatment in some cases and reached its peak 1 week after the completion of the treatment with a concentration of 247.8 ng g)1, which was approximately more than 50 times higher than its minimal inhibitory concentration against dermatophytes. TBF was not detected at 8 weeks post-treatment, although its concentration was 50.73 ng g)1 at 6 weeks post-treatment. Its effectiveness rate (effective + markedly effective) was 95% (19 ⁄ 20) with no adverse reactions, including abnormal changes in the laboratory test values, in any patient. These results suggest that TBF is a useful drug to treat hyperkeratotic tinea pedis from the pharmacokinetic point of view.

Rational for drug dosimetry and duration of terbinafine in the context of recalcitrant dermatophytosis: Is 500 mg better than 250 mg OD or BD?

“…Another study used a lower dose of terbinafine at 125 mg OD and found that the concentration in the stratum corneum in hyperkeratotic type tinea pedis cases, was 247.80 ng/g, which was approximately 50 times higher than the MIC (3–5 ng/ml) at 1-week posttreatment, and was still higher than the MIC, at 50.73 ng/g, 6-week posttreatment. [ 9 ] Hence, at conventional doses (125–250 mg), the drug is not only secreted preferentially through the sebum-to-lipid rich sites but also achieves higher levels than the serum. Thus, with conventional doses, MIC levels are thus, there is little rationale for a higher dose as seen in this study.…”

Recent updates in oral terbinafine: its use in onychomycosis and tinea capitis in the US

“…21 In 2008, Kawana et al performed a study on the concentrations of terbinafine in the stratum corneum and the efficacy of treatment in hyperkeratotic-type tinea pedis. 22 This study treated 20 patients, who had failed other therapies, with oral terbinafine 125 mg daily for 4 weeks and observed for 8 weeks post-treatment. Throughout the study, five patients were used to study the terbinafine concentration in the stratum corneum.…”