In-vitro activity of commonly used antifungal agents in the presence of rifampin, polymyxin B and norfloxacin against Candida albicans.

This study assessed the in-vitro antifungal activity against Candida albicans of amphotericin B, ketoconazole and miconazole, each in the presence of rifampin, polymyxin B and norfloxacin. Evaluation of drug interactions was estimated by the checkerboard pattern broth dilution method and by time-kill studies. Rifampin reduced the activity of the three antifungal agents used, with the reduction being more pronounced with amphotericin B. Synergy was observed when polymyxin B was combined with any of the antifungal agents used. The addition of norfloxacin resulted in minimal, if any, change in the activity.