Antibiotic selection in the treatment of endophthalmitis: the significance of drug combinations and synergy.

Emerging resistance of organisms to standard antibiotic therapy has forced clinicians to continually evaluate the best intraocular antibiotics for the treatment of endophthalmitis. Early diagnosis and appropriate treatment with intraocular antibiotics are important factors in the successful management of endophthalmitis. Although drug combinations are necessary to cover the full range of bacteria causing endophthalmitis, antimicrobial synergy is probably less important in endophthalmitis treatment because of the high intravitreal concentration of individual antibiotics achieved by intravitreal injection. In the treatment of bacterial endophthalmitis, the combination of intravitreal vancomycin (1 mg/0.1 cc) and ceftazidime (2.25 mg/ 0.1 cc) is a reasonable alternative to the combination vancomycin and amikacin (0.4 mg/ 0.1 cc).