Abstract
Background
Macrolide-resistant Mycoplasma pneumoniae (MRMP) complicates the treatment of pediatric M. pneumoniae pneumonia (MPP). We evaluated whether treatment with doxycycline, compared with azithromycin, was associated with faster first documented negative conversion of M. pneumoniae RNA (MP-RNA) and clinical recovery during a period of high macrolide resistance prevalence.Methods
This retrospective cohort study included 137 children hospitalized with MPP between October 2023 and January 2025 who received azithromycin (n = 90) or doxycycline (n = 47) monotherapy initiated on admission. MP-RNA was monitored using simultaneous amplification and testing. The primary endpoint was the time from the first antibiotic dose to first documented MP-RNA negative conversion. Multivariable Cox regression, propensity score overlap weighting, and an approximate interval-censored Weibull accelerated failure time model were used.Results
The doxycycline group was older and had greater baseline disease severity. The median time to first documented MP-RNA negative conversion was shorter with doxycycline than with azithromycin (6.0 vs. 10.0 days; P Conclusions
Doxycycline use was associated with faster first documented MP-RNA negative conversion and clinical recovery than azithromycin. These retrospective, nonrandomized findings do not establish causal superiority. Doxycycline may be considered when macrolide resistance is confirmed or strongly suspected, but prospective multicenter studies are required.