Comparative studies on the efficacy of AmBisome and Fungizone in a mouse model of disseminated aspergillosis.

OBJECTIVES The efficacy of intravenous injections of a liposomal formulation of amphotericin B (AmBisome) and amphotericin B deoxycholate (Fungizone) was evaluated in immunocompetent and temporarily leucopenic mouse models of disseminated aspergillosis using seven isolates of Aspergillus. METHODS Mice were infected with the organisms via tail veins. At 4 h after infection, antifungals were administered intravenously. For 30 days the number of mice surviving was recorded. RESULTS AmBisome at 1 mg/kg or higher significantly prolonged the survival time of mice infected with five out of seven isolates of Aspergillus compared with the control group. There was no difference in in vivo activity between AmBisome and Fungizone at 1 mg/kg in six isolates of Aspergillus. At the maximum tolerated dose of antifungals, however, AmBisome (10 mg/kg) showed greater efficacy than Fungizone (1 mg/kg). CONCLUSIONS These results suggest that the overall protective activity of AmBisome against disseminated aspergillosis is superior to that of Fungizone.