Synergistic activity of azoles with amiodarone against clinically resistant Candida albicans tested by chequerboard and time–kill methods

Abstract

Candida albicans is the most common candidal pathogen, causing serious systemic disease in immunocompromised patients. Azoles are widely applied and largely effective; however, they are generally fungistatic and clinically resistant isolates are emerging increasingly. The present study provided in vitro evidence using a chequerboard technique that amiodarone is strongly synergistic with azoles against resistant C. albicans, with mean fractional inhibitory concentration indices of 0.01 and high-percentage synergistic interactions of 1250 %. A time–kill study performed by both colony counting and a colorimetric reduction assay confirmed the synergistic interaction, with a ≥2 log₁₀ decrease in c.f.u. ml⁻¹ compared with the corresponding azoles alone. These results suggest the possibility of supplementing azoles with amiodarone to treat resistant C. albicans infections.