The antifungal activity of F901318 against Aspergillus fumigatus strain 16216, which is a TR34/L98H mutant (triazole resistant), in an isodose experiment. The open squares are the mean values ± standard errors of the means (SEM) of the galactomannan index for three mice. The solid line is the fit of the mathematical model to the PK-PD data set. In this experiment, a total daily dose of 24 mg/kg/day was administered once (B), two one-half dosages were administered twice (C), and three one-third dosages were administered every 8 h (D). There was a progressively greater effect, as smaller dosages were administered more frequently. Overall, galactomannan-time profiles were significantly different between regimens (P < 0.001). Compared to the results for the control, galactomannan profiles over time were significantly different for 12 mg/kg q12h (P = 0.028) and 8 mg/kg q8h (P = 0.024). No difference was detected for 24 mg/kg q24h versus the controls over time.