Is Ceftazidime/Avibactam an Option for Serious Infections Due to Extended-Spectrum-β-Lactamase- and AmpC-Producing Enterobacterales?: a Systematic Review and Meta-analysis

Carbapenem-sparing regimens are needed for the treatment of infections caused by extended-spectrum-β-lactamase (ESBL)- and AmpC-producing members of the Enterobacterales. We sought to compare the clinical efficacy of ceftazidime/avibactam and carbapenems against ESBL- and AmpC-producing Enterobacterales species. A systematic review and meta-analysis of randomized controlled trials comparing ceftazidime/avibactam with carbapenems for the treatment of ESBL- and AmpC-producing Enterobacterales was conducted. Five randomized controlled trials (RCTs) with ESBL- and AmpC-specific outcome data were compiled. Of the 246 patients infected with an ESBL-producing microorganism in the ceftazidime/avibactam arm, 224 (91%) had a clinical response at test of cure (TOC), versus 240 of 271 (89%) patients in the carbapenem arm (risk ratio [RR], 1.02; 95% confidence interval [CI], 0.97 to 1.08; P = 0.45; I(2) = 0%). Clinical response rates for AmpC producers in the ceftazidime/avibactam and carbapenem arms were 32/40 (80%) and 37/42 (88%), respectively (RR, 0.91; 95% CI, 0.76 to 1.10; P = 0.35; I(2) = 0%). Microbiological response and mortality rates were not reported specifically for ESBL/AmpC producers. Ceftazidime/avibactam may be a carbapenem-sparing option for the treatment of mild to moderate complicated urinary tract and intra-abdominal infections caused by ESBL-producing Enterobacterales species, and the data are too limited to provide any conclusive recommendations for the AmpC producers. Care should be taken before extrapolating this to severe infections, given that the representation of this population in the reviewed studies was negligible. Ceftazidime/avibactam is a costly drug active against carbapenem-resistant microorganisms and should be used judiciously to preserve its activity against them.