Recurrent wheezing and asthma often occur after severe RSV bronchiolitis1. Aiming to solve this clinical problem, Prof. Avraham Beigelman (Schneider Children's Medical Center of Israel, Israel) and co-investigators developed a randomised trial to analyse whether azithromycin outperformed placebo with respect to recurrent wheezing in hospitalised patients with RSV bronchiolitis (n=200; 1–18 months of age). The primary results did not demonstrate a difference between placebo and azithromycin on recurrent wheezing after an RSV infection2. During his talk at ERS 2022, Prof. Beigelman presented the results of a post-hoc analysis of this trial, investigating the influence of non-macrolide antibiotics on the effect of azithromycin on recurrent wheezing3.
In patients receiving other antibiotics next to azithromycin (30%), there was no difference in the risk for recurrent wheezing between the azithromycin arm and the placebo arm (HR 0.94; 95% CI 0.43–2.07; P=0.88). In contrast, in the ‘no-other antibiotic-stratum’ patients receiving placebo performed better than patients receiving azithromycin (HR 1.79; 95% CI 1.03–3.1; P=0.037). In fact, the study showed that the use of any antibiotic may increase the risk of recurrent wheezing compared with placebo (HR 1.65; 95% CI 1.00–2.72; P=0.048).
“These results indicate that azithromycin, and likely any other antibiotic agent, should be avoided during early-life, severe RSV bronchiolitis,” emphasised Prof. Beigelman. “In our next project, we will investigate whether the harmful effect of antibiotics is due to the impact these medications have on the gut microbiome.”