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

We investigated the efficacy of a potent new antipseudomonal beta-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 less than 0.01), prevention of pulmonary infarction (p less than 0.05), reduction of mean vegetation titers of Pseudomonas aeruginosa (p less than 0.05-p less than 0.0005), sterilization of vegetations (p less than 0.0005) and reduction in prevalence of bacteriologic relapses after therapy (p less than 0.005). There was no development of resistance in vivo to either amikacin or ceftazidime.