Low dose Azithromycin effective in refractory chronic rhinosinusitis: Study

According to recent research findings, a 4‐month course of 250 mg of azithromycin 3 times weekly in patients with refractory CRS significantly decreases S. aureus abundance in the sinonasal microbiome. Findings have been put forth in the International Forum of Allergy & Rhinology, Annual ARS Meeting on September 13‐14, 2019.

This study, attempted to assess changes in the sinonasal microbiome after a 4‐month course of low‐dose azithromycin. Researchers designed a double‐blind, randomized, placebo‐controlled trial including 48 adults with refractory chronic rhinosinusitis (CRS). Individuals were assigned randomly to 250 mg of azithromycin or placebo 3 times weekly for 4 months. The data showed that, in patients with refractory CRS, a 4‐month course of 250 mg of azithromycin 3 times weekly significantly lowers S. aureus abundance in the sinonasal microbiome. Azithromycin may constitute an additional therapeutic option to help control refractory CRS considering the pathogenic role of S. aureus in this disease.

The sinonasal microbiome is believed to play an important role in the pathophysiology of refractory chronic rhinosinusitis (CRS). The team evaluated changes in the microbiome following a 4‐month course of low‐dose azithromycin. Assessing microbiome alterations following such a treatment may help identify underlying mechanisms of this drug.

For the study design,a total of 48 adults with refractory CRS were enrolled in a double‐blind, randomized, placebo‐controlled trial. Patients were randomized to 250 mg of azithromycin or placebo 3 times weekly for 4 months. During this time, daily budesonide saline irrigations were continued. Sinonasal swabs were collected by endoscopically‐assisted method prior to treatment initiation and at the end of it, and sent for 16S ribosomal RNA gene sequencing. High‐resolution ANCHOR pipeline was used to infer and annotate putative species. The 2 patient groups were compared using DESeq2 differential abundance analysis.

Data analysis revealed some interesting facts.

• From initiation to the end of azithromycin treatment, patients showed a significant difference in beta diversity analysis (p = 0.0004) along with a significant decrease in 71 different operational taxonomic units (OTUs) of Staphylococcus aureus (false discovery rate [FDR] < 0.05) obtained from the differential abundance analysis.
• This was not observed in placebo‐treated patients. By the end of treatments, azithromycin‐treated patients had a significant decrease in 29 different OTUs of S. aureus (FDR < 0.05) when compared to placebo.

"Considering the pathogenic role of S. aureus in the refractory CRS population, azithromycin may constitute an additional therapeutic option to help control this disease."the team concluded.

For full article follow the link: https://doi.org/10.1002/alr.22653

Primary source: International Forum of Allergy & Rhinology