Efficacy and safety of tazobactam/ceftolozane in combination with metronidazole for intraabdominal infection in a hepato-biliary-pancreatic field in clinical practice

Introduction: This single-center study evaluated the efficacy and safety of tazobactam/ceftolozane (TAZ/CTLZ) in combination with metronidazole for intraabdominal infection in a hepato-biliary-pancreatic field in clinical practice.Methods: This study included 50 patients, including 35 with intraabdominal abscess or peritonitis, 5 with liver abscess, 4 with cholecystitis, and 6 with cholangitis with sepsis. Of the 50 patients, 29 received TAZ/CTLZ and metronidazole after a prior antibacterial therapy failure, including tazobactam/piperacillin, cefmetazole, and levofloxacin. Source control was performed in 36 patients.Results: The clinical response could be evaluated in 49 patients. The clinical cure rate at end-of-therapy was 91.8% (45 of 49 patients) and that at test-of-cure was 89.6% (43 of 48 patients). Of 5 patients in whom clinical response at test-of-cure was a failure, 1 developed infectious disease during chemoradiotherapy for recurrent cancer and 4 after liver resection or pancreatoduodenectomy. Three of the 4 patients were associated with pancreatic juice leakage. Isolated pathogens were eradicated or presumably eradicated in 27 of 31 (87.1%) patients in whom microbiological response at test-of-cure could be evaluated. The response rate for AmpCproducing Enterobacteriaceae was 87.5%. Nausea was observed in two patients. Aspartate and alanine aminotransferase activities were increased in 3 of the 50 (6.0%) patients. The activities improved after the antibiotic discontinuation.Conclusions: This observational study demonstrated that TAZ/CTLZ in combination with metronidazole has a favorable effect without major drug-related adverse events for intraabdominal infection in the hepato-biliarypancreatic field in clinical practice although the efficacy of TAZ/CTLZ may decrease in compromised patients.