Terbinafine 250mg/5ml oral suspension

BackgroundThe emergence of Trichophyton indotineae as a multidrug-resistant dermatophyte has challenged conventional therapeutic approaches for dermatophytosis, leading to a significant therapeutic dilemma. The absence of formal epidemiological cutoff values (ECVs) under the Clinical and Laboratory Standards Institute (CLSI) framework has led to inconsistent interpretation of antifungal susceptibility testing (AFST) data, highlighting the urgent need for standardised susceptibility interpretation criteria and effective therapeutic strategies.ObjectivesThis study aimed to (1) establish CLSI-based estimated tentative ECVs (ET-ECVs) to facilitate reliable minimum inhibitory concentration (MIC) interpretation; (2) analyse resistance rates of T. indotineae to terbinafine, itraconazole and voriconazole using a large-scale global dataset and (3) explore and identify effective therapeutic options following first-line treatment failure.MethodsThis systematic review compiled global susceptibility data for T. indotineae through comprehensive literature searches, including only studies that performed CLSI- or European Committee on Antimicrobial Susceptibility Testing (EUCAST)-standardised AFST. Furthermore, the clinical efficacy of voriconazole was specifically evaluated by summarising and analysing reported treatment cases.ResultsA total of 67 studies from 14 countries, comprising 981 isolates, were included. The proposed CLSI ET-ECVs for terbinafine, itraconazole and voriconazole were 0.125, 0.25 and 1 mg/L, respectively, showing full alignment with EUCAST tentative epidemiological cutoff values (TECOFFs). Integrated resistance rates were 77.6% for terbinafine, 17.0% for itraconazole and 1.4% for voriconazole. Cross-resistance analysis revealed that terbinafine resistance predominated, with 14.3% of isolates co-resistant to itraconazole. In vitro susceptibility data demonstrated high activity of voriconazole and clinical case summaries further confirmed its favourable therapeutic efficacy, with complete remission reported in all evaluated cases.ConclusionThis study defined the CLSI ET-ECVs for interpreting T. indotineae MICs, highlighted the resistance burden to first-line agents and provided in vitro evidence supporting further evaluation of voriconazole as a potential effective alternative therapy. These findings may provide critical warnings regarding the high-resistance landscape and help guide antifungal susceptibility interpretation for this emerging multidrug-resistant pathogen.

Abstract licence: CC BY

Background/Objectives: In recent years, reports regarding terbinafine resistance in Trichophyton spp. have increased. The aim of this study is to evaluate the prevalence of terbinafine resistance in Trichophyton spp. species on a regional and species basis and to systematically analyze the antifungal susceptibility testing methods used and the available data. Methods: This systematic review and meta-analysis was conducted in accordance with the PRISMA guideline. Studies published until 1 December 2025 were searched in the PubMed/MEDLINE, Scopus, Web of Science, and Embase databases. Studies reporting antifungal susceptibility test results using species-level identification, standardized, or study-defined methodologies were included. Pooled prevalence estimates were calculated with a random-effects model. Heterogeneity was evaluated with the I2 statistic. Subgroup analyses were performed according to publication period, resistance definition groups, species, and geographic region. SQLE mutation patterns were summarized descriptively. Results: Nineteen studies reported from 13 different countries were included in the meta-analysis. In sensitivity analyses that included surveillance-based studies, the combined prevalence rate was found to be 3.2% (95% confidence interval 1.5-6.7). Higher descriptive resistance levels were observed in T. indotineae and T. mentagrophytes, although species-related differences were not statistically significant. Among studies reporting SQLE mutations, alterations involving codons 393 and 397 were the most frequently described; however, mutation patterns were summarized descriptively because of methodological heterogeneity among studies. Conclusions:Trichophyton spp. terbinafine resistance is an emerging global threat. Standardized susceptibility testing, harmonized epidemiological cut-off values, and enhanced molecular surveillance are essential for accurate detection, resistance monitoring, and effective clinical management.

Abstract licence: CC BY