Clinical Outcomes and Safety of Meropenem-Colistin versus Meropenem-Tigecycline in Patients with Carbapenem-Resistant Acinetobacter baumannii Pneumonia

Abstract

This study compared the clinical outcomes and safety of meropenem-colistin versus meropenem-tigecycline in the treatment of adult patients with carbapenem-resistant Acinetobacter baumannii (CRAB) pneumonia. A retrospective observational study of patients with CRAB pneumonia was performed at a 1048-bed university-affiliated hospital in the Republic of Korea between June 2013 and January 2020. All adult patients initially treated with meropenem-colistin were compared with those treated with meropenem-tigecycline to evaluate in-hospital mortality and adverse events. Altogether, 66 patients prescribed meropenem-colistin and 24 patients prescribed meropenem-tigecycline were included. All patients had nosocomial pneumonia, and 31.1% had ventilator-associated pneumonia. The minimum inhibitory concentrations of meropenem <= 8 mu g/mL and tigecycline <= 2 mu g/mL were 20.0% and 81.1%, respectively. The in-hospital and 28-day mortality rates were 40% and 32%, respectively. In the Cox proportional hazard regression analysis, predictors associated with in-hospital mortality included procalcitonin >= 1 ng/mL (adjusted hazard ratio (aHR), 3.39; 95% confidence interval (CI) 1.40-8.19; p = 0.007) and meropenem-colistin combination therapy (aHR, 2.58; 95% CI, 1.07-6.23; p = 0.036). Episodes of nephrotoxicity were significantly more common in the meropenem-colistin group than in the meropenem-tigecycline group (51.5% vs. 12.5%, p = 0.001). Meropenem-tigecycline combination therapy might be a valuable treatment option for patients with CRAB pneumonia.