Abstract
The in vitro activities of two antifungal drugs in combination with four nonantifungal ophthalmic agents were evaluated using a broth microdilution method and a collection of eight Fusarium ocular isolates that exhibited resistance to both natamycin (MICs, 14 to 32 μg/ml) and voriconazole (MICs, 4 to >128 μg/ml). Synergistic and indifferent interactions were observed for natamycin and 5-fluorouracil and natamycin with timolol dependent on the Fusarium isolate tested. Isolate-dependent synergistic and indifferent interactions were also observed for natamycin with EDTA and natamycin with dorzolamide. Synergistic or indifferent interactions were observed for voriconazole with timolol and voriconazole with 5-fluorouracil depending on Fusarium isolate. Taken together, these data suggest that commonly used ophthalmic agents enhance the in vitro activity of antifungal drugs against drug-recalcitrant ocular fungal pathogens.