In-vitro effects of liposome-encapsulated amphotericin B (AmBisome) and amphotericin B-deoxycholate (Fungizone) on the phagocytic and candidacidal function of human polymorphonuclear leucocytes.

Liposomal amphotericin B (AmBisome), at concentrations > or = 20 mg/L, and amphotericin B-deoxycholate (DC) (Fungizone), at concentrations > or = 1 mg/L, both caused a significant reduction in neutrophil uptake of Candida albicans blastospores following simultaneous addition of the drug with the blastospores. The reduction in uptake was seen also in tests in which blastospores were pre-treated with the drugs for 60 min, but was not detected in tests in which neutrophils were pre-treated for 60 min. Neither formulation affected neutrophil killing of C. albicans blastospores following simultaneous addition of the drug with the blastospores. However, previous treatment of the neutrophils with either formulation at a concentration of 20 mg/L led to enhanced killing of ingested blastospores. The results suggest that much higher concentrations of liposomal amphotericin B (AmBisome) are required to produce deleterious effects on neutrophil phagocytic function than with the conventional formulation of the drug.