According to the author, however, more recent research has identified potential benefits for inhaled formulations. In fact, she notes, multiple studies have shown that “antibiotic concentrations achieved… with targeted therapy far exceed the minimum inhibitory concentration (MIC) of pathogens with very low or nondetectable levels in the serum.” And this has yielded promising results in multiple studies.
A meta-analysis of recent studies by Zampieri et al
, for example, found that inhaled antibiotics “had higher rates of clinical cure” with no differences in microbiological cure, mortality, duration of mechanical ventilation, ICU length of stay, or renal toxicity. And, a study
in which 60 critically-ill intubated patients received inhaled colistin for the treatment of VAP caused by multidrug-resistant pathogens (Acinetobacter baumannii
, Pseudomonas aeruginosa
, and Klebsiella pneumoniae
) found that 83% of them achieved bacteriologic and clinical response.
Finally, in a study
performed by her own team, Dr. Palmer notes that 8 of 24 participants receiving placebo inhaled antibiotic and systemic antibiotics acquired resistant organisms during treatment compared with 0 of 19 patients receiving inhaled antibiotics alone. In the placebo group receiving only systemic antibiotics, 4 participants with sensitive bacteria developed resistance, while only 1 of the 19 patients receiving inhaled antibiotics acquired a resistant organism.
In her concluding remarks, Dr. Palmer writes, “In view of the threat of increasingly resistant organisms present in the ICU… large multicenter trials targeting antimicrobial therapy to the lung are needed… Clinical trials must be designed to assess not only clinical end points such as resolution of signs and symptoms of respiratory infection, but, data should also be acquired for new primary outcomes, such as effects on the amounts and duration of systemic antibiotic used. Trials should also document antimicrobial resistance in the ICU….”
Brian P. Dunleavy is a medical writer and editor based in New York. His work has appeared in numerous healthcare-related publications. He is the former editor of Infectious Disease Special Edition.
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