Using ceftazidime-avibactam rather than colistin to treat patients with carbapenem-resistant Enterobacteriaceae (CRE) infections may yield better outcomes, according to a recent study.
Researchers enrolled 137 patients with CRE infections initially treated with either ceftazidime-avibactam (n=38) or colistin (n=99) who participated in a previous multicenter study, Consortium on Resistance Against Carbapenems in Klebsiella and other Enterobacteriaceae (CRACKLE).
The most common infections among participants were of the bloodstream (n=63, 46%) and respiratory tract (n=30, 22%), and most patients received additional anti-CRE treatments. Nearly all patients (n=133, 97%) were infected with Klebsiella pneumoniae, while the other four (3%) were infected with Enterobacter species.
The researchers analyzed the efficacy of each treatment by comparing patients' disposition 30 days after treatment initiation. They adjusted all analyses for confounders with covariates including the Pitt bacteremia score, type of infection, and creatinine level ≥2 mg/dL at time of first positive culture. Results were published online on Sept. 4 by Clinical Infectious Diseases.
Patients who received ceftazidime-avibactam had significantly lower adjusted all-cause hospital mortality 30 days after treatment initiation compared to those who received colistin (9% vs. 32%; difference, 23% [95% bootstrap CI, 9% to 35%]). Furthermore, 30 days after starting treatment, the adjusted probability of a better outcome on ceftazidime-avibactam versus colistin was 64% (95% CI, 57% to 71%), according to desirability of outcome ranking analyses.
The authors noted limitations to the study, such as its observational design, the possibility of unmeasured confounders, and the relatively small number of participants. They concluded that ceftazidime-avibactam may be a “reasonable alternative” to colistin when treating patients with Klebsiella pneumoniae carbapenemase-producing CRE infections. The results must be confirmed in a randomized controlled trial, they wrote, noting that unfortunately no such data on ceftazidime-avibactam are “imminently expected.”