Efficacy of Amikacin, Ofloxacin, Pefloxacin, Ciprofloxacin, Enoxacin and Fleroxacin in Experimental Left-Sided Pseudomonas aeruginosa Endocarditis

The efficacies of amikacin, ofloxacin, pefloxacin, ciprofloxacin, enoxacin and fleroxacin, each as monotherapy, were evaluated in a rabbit model of induced left-sided Pseudomonas aeruginosa endocarditis. Therapy started 48 h after infection and lasted 5 days. All agents were given intramuscularly; amikacin at 7 mg/kg/12 h, and each quinolone at 35 mg/kg/12 h. All animals survived except for 1 of the group that received amikacin, and 2 of the untreated control group. No sterile vegetations were found in the untreated group and the group of fleroxacin, while 3 animals from the amikacin, ofloxacin, and enoxacin groups, and 2 from the ciprofloxacin and pefloxacin groups had sterile vegetations. All agents used significantly reduced the number of CFU per gram of vegetation versus untreated controls. Enoxacin and ciprofloxacin were equipotent and more effective than pefloxacin, ofloxacin and amikacin. Fleroxacin had a weaker activity.