Ceftolozane-tazobactam vs. colistin for the treatment of infections due to multidrug-resistant Pseudomonas aeruginosa: a multicentre cohort study

ABSTRACT: Objectives: The aim of this study was to compare the safety and effectiveness of ceftolozane-tazobactam (C-T) to colistin-based regimen for treating infections caused by multidrug-resistant (MDR) Pseudomonas aeruginosa. Methods: This was a retrospective, multicentre, observational cohort study of inpatients who received either C-T or intravenous colistin for treating infections caused by MDR P. aeruginosa. The study was conducted in five tertiary care hospitals in Saudi Arabia. The main study outcomes included clinical cure at end of treatment, in-hospital mortality, and acute kidney injury (AKI). Univariate analysis and multivariate logistic regression model were conducted to evaluate the independent effect of C-T on the clinical outcome. Results: A total of 184 patients were included in the study: 82 patients received C-T, and 102 patients received colistin-based regimen. Clinical cure (77% vs. 57%; P = 0.005; OR, 2.52; 95% CI, 1.32–4.79) was significantly more common in patients who received C-T. After adjusting the difference between the two groups, treatment with C-T is independently associated with clinical cure (adjusted OR, 2.47; 95% CI, 1.16–5.27). In-hospital mortality (39% vs. 49%; P = 0.175; OR, 0.67; 95% CI, 0.37–1.20) was lower in patients who received C-T, but the difference was not significant. AKI (15% vs. 41%; P < 0.001; OR, 0.25; 95% CI, 0.12–0.51) was significantly less common in patients who received C-T. Conclusion: C-T is associated with a higher rate of clinical cure and lower rate of AKI compared to colistin. Our findings support the preferential use of C-T over colistin-based regimen for treating these infections.