Therapeutic efficacy of 29 antimicrobial regimens in experimental intraabdominal sepsis.

An animal model of colonic perforation was used to examine the efficacy of 29 antimicrobial regimens in the treatment of intraabdominal sepsis. Efficacy was judged on mortality during the first 12 days after challenge and on the incidence of intraabdominal abscess noted at necropsy upon completion of the experiment. In general, antimicrobial agents that are active against coliform bacteria prevented early mortality, whereas drugs that are active against Bacteroides fragilis were most effective in reducing the incidence of late abscess formation. Exceptions were metronidazole, which produced a significant reduction in early mortality, and chloramphenicol, which caused only a modest reduction in the incidence of abscess. Optimal results were obtained with several regimens that showed good in vitro activity against both coliforms and B. fragilis.