Azithromycin for Children Hospitalized With Asthma

Asthma is a chronic lung condition that accounts for over 130,000 pediatric hospitalizations nationally at a cost of almost 1.4 billion dollars. Atypical pathogens have been implicated both in initiating asthma and triggering acute asthma exacerbations. Azithromycin, a macrolide antibiotic, is known to have antibacterial activity against atypical pathogens and gram positive bacteria. More recently, macrolides have been increasingly used and effective against gram negative bacteria and inflammation in the lungs of patients with chronic respiratory illnesses. This effect may be secondary to the immunomodulatory effects macrolides possess, in addition to their anti-bacterial effects. In long-term therapy with macrolides, patients with asthma have shown improved bronchiolar hyperreactivity, spirometry, symptoms, and quality of life. However, studies of short-term treatment in the acute setting and in children are limited. Some practitioners use azithromycin in the treatment of acute asthma, despite limited data.

The investigators propose a double-blind, randomized, placebo-controlled trial of azithromycin in children aged 4-12 years with persistent asthma hospitalized with acute asthma exacerbations. Children will be enrolled within 12 hours of admission and will be randomized to receive three days of either azithromycin or placebo suspension (10mg/kg/dose, max of 500mg). The primary outcome measure will be length of stay (LOS). Secondary outcome measures will include: days of school/work missed, readmission rates, return to medical care rates, recurrence of symptoms, and steroid courses. In the future, patients may also be approached to enroll in the "Mechanism Subset Study" a separate pilot and feasibility study which will require two blood samples and two nasal aspirate samples and will test for atypical pathogens, interleukin-8 levels, and neutrophil/eosinophil counts. The average length of stay for patients in this age range with asthma in 2011 at our institution was 3.0 days. The investigators will enroll to achieve a power of 80%, with an alpha of 0.05, which will require 107 patients in each group to detect a 16 hour (0.67 day) difference in the primary outcome, LOS. This study hypothesizes that azithromycin treatment in children hospitalized with acute asthma will decrease LOS.