Comparative study of colistin methanesulfonate and colistin sulfate/ polymyxin B in the treatment of ceftazidime-avibactam resistant Gram-negative bacilli infections.

Objective: To evaluate the clinical efficacy of different species of polymyxin drugs in the treatment of Carbapenem- Resistant Gram-negative bacilli (CR-GNB) resistant to ceftazidime-avibactam (CZA). Methods: Patients infected by CR-GNB strains and treated with polymyxin drugs were selected and divided into colistin methanesulfonate (CMS) group and colistin sulfate/polymyxin B (CSPB) group to observe clinical efficacy and safety. Results: 65 patients were eventually included (CMS group, n = 29; CSPB group, n = 36). The clinical efficacy, microbiological eradication rate and 28-day mortality between the two groups were similar, with no statistical significance (51.72% vs. 50.00%, p = 0.890; 55.17% vs. 52.78%, p = 0.847; 17.24% vs. 25.00%, p = 0.449). With regard to renal safety, the incidence of acute kidney injury (AKI) in the CMS group was significantly higher than that in the CSPB group (34.48% vs. 5.56%, p = 0.003). Among them, the incidence of AKI grade 3 in the CMS group tended to be higher than that in the CSPB group (24.14% vs. 5.56%, p = 0.066). Conclusion: The results based on small sample size from a single center showed that clinical response to the treatment of ceftazidime-avibactam resistant Gram-negative bacillus infections is similar for CMS and Colistin Sulfate/Polymyxin B, but the nephrotoxicity of CMS is greater than that of polymyxin sulfates. [ABSTRACT FROM AUTHOR]