Usefulness of 1% terbinafine HCl (Lamisil) cream for hyperkeratotic-type tinea pedis and its transfer into the horny layer.

The usefulness of 1% terbinafine HCl (Lamisil) cream for hyperkeratotic-type tinea pedis and its transfer into the horny layer were evaluated. Of the 36 patients enrolled in the study, 35 were retained for analysis and one was excluded due to inappropriate drug application. Hyperkeratotic-type tinea pedis was classified into three types: true hyperkeratotic-type, partial hyperkeratotic-type, and quasi-hyperkeratotic type. The overall clinical improvement rate was 95.5% (100% for true-, 80% for partial- and 96.2% for quasi-hyperkeratotic type). The overall fungal eradication rate was 88.6% (75% for true-, 100% for partial- and 88.5% for quasi-hyperkeratotic type). The overall efficacy rate was 88.6% (75% for true-, 100% for partial- and 88.5% for quasi-hyperkeratotic type). No adverse reactions were reported. Drug concentrations in the horny layer were 170.3, 228.5 and 249.2 ng mg-1, respectively, 2, 4 and 12 weeks after starting the treatment. These concentrations are more than 50,000 times higher than the minimum inhibitory concentrations of terbinafine for dermatophytes. These findings indicate that terbinafine HCl (Lamisil) cream is very useful for refractory hyperkeratotic-type tinea pedis when administered alone. The pharmacokinetic data also support the clinical and mycological findings.