POTENT SYNERGISTIC EFFECT OF DOXYCYCLINE WITH FLUCONAZOLE AGAINST CANDIDA ALBICANS

摘要

Doxycycline was found to act synergistically with the antifungal fluconazole against Candidaalbicans. Combination with doxycycline converts fluconazole from fungistatic to fungicidal, prevents the onset of drug resistance, and is also effective against a clinical isolate characterized by elevated resistance to fluconazole. Investigation on the interactions between the two drugs by way of checkerboard assays indicated that doxycycline had an influence on the MIC for fluconazole, as defined by CLSI standards, only at high concentrations (200 µg/ml). However, lower concentrations were effective in eliminating residual cell growth at supra-MIC concentrations of fluconazole. Using MIC-0, defined as a drug combination resulting in optically clear wells, as an endpoint, doxycycline was found to be synergistic with fluconazole at a concentration as low as 25 µg/ml, with a fractional inhibitory concentration index 0.5.