LAUSR

Key Points Question Is azithromycin (AZM) safe, and does it reduce nasal and endotracheal matrix metalloproteinase 9 (MMP-9) levels in children with respiratory syncytial virus–induced respiratory failure? Findings In this randomized phase 2 clinical trial that included 48 children admitted to the pediatric intensive care unit with respiratory syncytial virus lung disease who required positive pressure ventilation, AZM was safe. No difference in nasal MMP-9 levels was observed between treatment group, but in those who required mechanical ventilation and received a high dose of AZM, endotracheal active and total MMP-9 levels were lower on day 3 of treatment. Meaning In this study, high doses of AZM were safe, reduced endotracheal MMP-9 levels in patients receiving mechanical ventilation, and potentially improved outcomes in critically ill children with respiratory syncytial virus infections.