Nasopharyngeal flora and drug susceptibility in children with macrolide therapy

摘要

Low-dose, long-term administration of macrolides (macrolide therapy) has been used as an effective treatment for chronic respiratory tract diseases. We investigated the nasopharyngeal flora in children treated by macrolide therapy. Nasopharyngeal cultures were obtained from 78 children with chronic rhinosinusitis and/or otitis media with effusion (OME) at the end of the low-dose administration of clarithromycin (macrolide group). As controls, 108 children with chronic rhinosinusitis and/or OME to whom no macrolides were administered, were also included in the study. The macrolide therapy did not have a significant effect on the incidence or the susceptibility patterns of potential pathogens except for Moraxella catarrhalis. Most of the children of the macrolide group possessed a normal flora compared with the control children. The risk factors for carriage of erythromycin-resistant Streptococcus pneumoniae were male gender in the macrolide group, and age under 6 years and use of antimicrobial drugs other than macrolides in the control group. The clinical efficacy of the therapy was independent of carriage of erythromycin-resistant S. pneumoniae. We concluded that macrolide therapy has little effect on carriage of drug-resistant pathogens, and the efficacy of the therapy depends on the drugs' anti-inflammatory effect, which is independent of their antimicrobial effect.