Simultaneous Use of Other Antimicrobials May Have Influenced Clinical Outcomes

Abstract

TO THE EDITOR—We would like to commend Dr. Kofteridis and his colleagues for their recent excellent contribution to our understanding of treatment of multidrug-resistant Acintobacter [1]. Their investigation provides important data on the potential benefit of using aerosolized colistin for the treatment of ventilator-associated pneumonia due to multidrug-resistant organisms [1]. Although Kofteridis et al [1] conclude that the addition of aerosolized colistin did not provide therapeutic benefit, we favor Dr Patterson's interpretation that, “the combination of aerosolized plus intravenous colistin is potentially promising” [2, p. 1246]. Data from this investigation show a clear trend toward therapeutic benefit without a significant incidence of adverse events. In the Methods section, Kofteridis et al [1] comment that they collected data on prior and simultaneous use of antimicrobial agents. There are good data that suggest potential synergism between colistin and other antibiotic agents [3]. However, the use and distribution of simultaneous antimicrobial drugs was not described. Were there differences in antibiotic prescribing patterns between the 2 groups? Did the authors consider a secondary analysis to take into consideration the impact of additional therapy? This type of secondary or subgroup analysis has proven to be valuable in other similar studies [4]. We consider this article to be a timely and important addition to the medical literature. We are interested in seeing additional data, because they may improve our ability to interpret these results.