Comparing inhaled colistin with inhaled fosfomycin/tobramycin as an adjunctive treatment for ventilator-associated pneumonia: An open-label randomized controlled trial

Abstract

Purpose: Although investigations are limited, adjunctive aerosolized antibiotics have been advised in the setting of gram-negative ventilator-associated pneumonia (VAP). This study aimed to compare the efficiency of inhaled colistin with inhaled fosfomycin/tobramycin in treating VAP due to extensively drug-resistant (XDR) Acinetobacter baumannii. Methods: This single center open-label randomized controlled trial included 60 patients who developed XDR A. bumannii VAP. Eligible participants were randomly assigned to two groups (no. 30). Regardless of the assignment, all participants received meropenem (2 g as a 3-h extended infusion every 8 h) plus intravenous colistin (a loading dose of 9 million IU and then 4.5 million IU every 12 h). The control group was given inhaled colistin (1 million IU every 8 h), and the case group received inhaled tobramycin/fosfomycin (300 mg every 12 h/80 mg every 12 h) as adjunctive therapy. The primary outcome was treatment duration, and the secondary outcomes were Clinical Pulmonary Infection Score (CPIS) trend and mortality rate in the groups. The decision to stop treatment was made by the treating physician. Results: The mean treatment duration was 13.73 ± 3.22 days in the colistin group and 10.85 ± 2.84 days in the tobramycin/fosfomycin group; the mean treatment duration in the latter group was lower significantly (P = 0.001). CPIS was decreased in the groups significantly (P < 0.001), but the mean changes of CPIS were significantly different between the groups, and in the inhaled tobramycin/fosfomycin group, a greater reduction (P = 0.005) was observed. Two (6.67%) patients in the control group and three (10%) patients in the case group died. Conclusion: The use of inhaled tobramycin/fosfomycin in cases with XDR A. bumannii VAP was associated with a shorter treatment duration in this open-label trial.