Synergistic Activities of Gatifloxacin in Combination with Other Antimicrobial Agents against Pseudomonas aeruginosa and Related Species

Drug combinations have been used to treat serious infections caused by Pseudomonas, Burkholderia, Stenotrophomonas, and Acinetobacter. In this study, the combined drug effects of gatifloxacin (GAT) and nonquinolones were determined by time-kill analysis at clinically achievable drug concentrations. Synergy (≥2 log(10)-enhanced killing at 24 h) was observed with GAT plus amikacin or a β-lactam against 50 to 75% of strains, including strains nonsusceptible to one or both drugs.