Amikacin + ceftazidime therapy of experimental right-sided Pseudomonas aeruginosa endocarditis in rabbits

We investigated the efficacy of a potent new antipseudomonal β-lactam agent, ceftazidime, in a model of right-sided Pseudomonas endocarditis in 72 rabbits. Animals received either: no therapy (controls), amikacin (15 mg/kg/day), ceftazidime (100 mg/kg/day) or amikacin + ceftazidime. Amikacin + ceftazidime was significantly more effective than single-drug regimens in terms of reduction of mortality (p<0.01), prevention of pulmonary infarction (p<0.05), reduction of mean vegetation titers of Pseudomonas aeruginosa (p<0.05 - p<0.0005), sterilization of vegetations (p<0.0005) and reduction in prevalence of bacteriologic relapse after therapy (p<0.005). There was no development of resistance in vivo to either amikacin or ceftazidime.