The Effectiveness of Colistin/Rifampin Compared to Colistin/Meropenem in the Treatment of Ventilator-associated Pneumonia Caused by Carbapenem-resistant Acinetobacter baumannii: A Randomized Controlled Clinical Trial.

Objective: Treating ventilator-associated pneumonia (VAP) caused by carbapenem-resistant Acinetobacter baumannii (CRAB) is still a significant challenge. This study evaluated the effectiveness of the colistin/rifampin regimen compared to the usual colistin/meropenem regimen in treating patients with VAP caused by CRAB.

Methods: In a randomized controlled clinical trial, the patients with CRAB-related VAP were randomly assigned to experimental (n = 21) and control (n = 24) groups. The first group received colistin 4.5 MIU IV infusion every 12 h and rifampin 300 mg PO every 12 h, and the second group received colistin with the same dose and meropenem 2 g IV every 8 h for 10 days. The clinical response (complete response, partial response, or treatment failure) and mortality rate at the end of the intervention were recorded and compared between the two groups.

Findings: The complete response rate was higher (n = 8; 66.70%), and the failure rate was lower (n = 4; 26.70%) in the experimental group than in the control group (n = 4; 33.30%, and n = 11; 73.30%, respectively), but the differences were not statistically significant. The mortality rate was three patients in both experimental (14.28%) and control (12.50%) groups; however, the difference was not statistically significant (P = 0.860; odds ratio: 1.143, 95% confidence interval: 0.258-5.067).

Conclusion: The colistin/rifampin combination can be considered an alternative regimen to colistin/meropenem in the treatment of VAP caused by CRAB.