AZithromycin Therapy in Preschoolers With a Severe Wheezing Episode Diagnosed at the Emergency Department

Overview

AZ-SWED is a parallel group, double blind, placebo control efficacy clinical trial with two separate hypotheses. The trial compared the 5-day outcome of preschool children presenting to an Emergency Department (ED) with an acute, severe wheezing episode and treated with either once daily oral Azithromycin (12 mg/kg/day for 5 days) or placebo. The AZ-SWED researchers made separate comparisons in children in whom specific pathogenic bacteria isolated from nasopharyngeal swabs, and in those in whom they were not isolated. The primary outcome was the Asthma Flare-up Diary for Young Children (ADYC), a validated instrument that caregivers will transmit electronically daily after discharge from the ED. Families were contacted daily during the five-day treatment to collect the ADYC, and to assess compliance and complications. A randomly chosen subset of enrolled children participated in two follow-up visits 5-8 days and 14-21 days after visit 1 to assess development of resistance to study drug and treatment response related changes in the airway microbiome.

This Phase III trial is designed as a parallel group, placebo-controlled, double-blind, randomized, multi-center evaluation of AZ for the treatment of acute wheezing episodes. The study recruited eligible patients from seven EDs. We tested two primary hypotheses: 1) AZ (12 mg/Kg/day) given for 5 days to preschool children with severe acute wheezing and harboring any of three specific pathogenic bacteria (H influenzae, M catarrhalis, or S pneumonia) in their nasopharynx will decrease the severity of the acute episode; and 2) AZ given on an identical schedule and dose will decrease the severity of wheezing episodes in children who do not harbor any of these three pathogenic bacteria in their nasopharynx. This study had three visits. All enrolled patients participated on the Day 0 visit for screening, the informed consent process, enrollment, randomization, treatment initiation and dispensing drug. A sub-group of randomly selected patients participated in two follow-up visits on Day 5 - 8 and Day 14 - 21 where they were tested for antibiotic resistance. The primary outcome was the sum of the Asthma Flare-up Diary for Young Children (ADYC) score, a validated instrument completed by the parent or guardian of the enrolled children during the 5-day treatment period. Secondary outcomes will include (1) ED length of stay (2) hospital length of stay, and (3) return ED visits or hospitalizations within 72 hours after randomization.