In vitro antifungal combination of terbinafine with itraconazole against isolates of Trichophyton spp.

Terbinafine is used as first-line therapy for dermatophytosis, but the incidence of terbinafine-resistance is increasing. Combination of terbinafine with itraconazole was tested by checkerboard based on the EUCAST methodology for antifungal susceptibility testing against 9 terbinafine-susceptible and 7 terbinafine-resistant clinical isolates of Trichophyton spp. from India. Synergistic interactions were observed for 4/9 of the susceptible isolates with fractional inhibitory concentration index (FICI) values of 0.3125 to 0.5 and for 4/7 of the resistant isolates with FICI values of 0.032 to 0.3125.