The antibiotic azithromycin may reduce the risk of recurrent wheezing in infants hospitalized with respiratory syncytial virus (RSV), according to a small pilot study at Washington University School of Medicine in St. Louis.
Evidence suggests that reduced wheezing may lower an infant’s risk of developing asthma over the next several years, researchers say in the Nov 18 issue of The Journal of Allergy and Clinical Immunology.
Respiratory infections are common in a child’s first years of life. Most are mild, but some infants develop such difficulty breathing, they must be hospitalized to keep their oxygen levels in normal range. The investigators focused on bronchiolitis caused by RSV.
Bronchiolitis is an inflammation of the small airways in the lungs. When severe enough to require hospitalization, bronchiolitis greatly increases the risk that a child will go on to develop recurrent wheezing — a whistling sound in the lungs — and asthma.
Researchers were interested in trying to stop the common pattern of wheezing after bronchiolitis, which often progresses to asthma.
They randomly gave azithromycin to half of the infants for two weeks and a placebo to the other infants over the same period. They analyzed levels of an immune system marker of inflammation in the blood and in mucus from the infants’ noses. Perhaps most relevant for patients, they also monitored the number of wheezing episodes in the following year.
The results showed no differences in the levels of inflammation markers in blood samples over the two weeks following bronchiolitis, but significantly lower levels of such markers in the nasal samples of babies receiving azithromycin.
“We think the findings in nasal mucus may be most relevant because RSV is a disease of the airway rather than a systemic disease in the blood,” said first author Avraham Beigelman, MD, an assistant professor of pediatrics who treats patients at St. Louis Children’s Hospital. “We also showed that the children who received azithromycin had fewer days with any respiratory symptoms, including wheezing, coughing and shortness of breath, over the following year.”