# Timing and efficacy of doxycycline in macrolide-resistant Mycoplasma pneumoniae pneumonia in children: a single-center retrospective study

## TL;DR

This study examines how effective doxycycline is for treating a specific type of pneumonia in children when other antibiotics fail.

## Contribution

The study evaluates the timing and efficacy of doxycycline in treating macrolide-resistant Mycoplasma pneumoniae pneumonia in children.

## Key findings

- Doxycycline showed an 80% fever reduction rate within 48 hours.
- Children treated with doxycycline required fewer adjuvant therapies like oxygen and bronchoscopy.
- Early doxycycline use reduced reliance on additional treatments, easing healthcare resource burden.

## Abstract

Outbreaks of macrolide-resistant Mycoplasma pneumoniae (MRMP) in children have posed ongoing treatment challenges. This study aimed to assess the efficacy of doxycycline in treating MRMPP at different time points, offering insights for public health strategies.

We retrospectively analyzed children with MRMPP hospitalized between September 2022 and February 2024. They were divided into three main groups based on antibiotic use: (1) those who received azithromycin only (AZI group); (2) those who received doxycycline only (DOX group); (3) those who received azithromycin followed by doxycycline (ATD group), divided into two subgroups according to the duration of azithromycin use: azithromycin use < = 3-day subgroup (ATD1) and azithromycin use > 3-day subgroup (ATD2). Oxygen therapy, electronic bronchoscopy, hormones and gamma globulin were also recorded. Length of hospital stay and duration of fever were used as outcome measures for comparative analyses. Propensity score matching (PSM) analysis was used to adjust the score.

312 eligible children were identified. The DOX group had the highest 48-h fever reduction rate (80%). The AZI group had a higher proportion of oxygen (77%) and e-bronchoscopy (75%) use, and the ADT group had a higher proportion of hormone use (39%). After adjustment for PSM, oxygen use remained higher in the ATD2 group than in the DOX+ATD1 group (p = 0.026).

Early use of doxycycline in treating MRMPP reduces reliance on adjuvant therapies, thus easing the burden on healthcare resources.

Study groups and key outcomes.Four panels depict data on medication groups and outcomes. The first panel shows three groups: AZI (azithromycin) with 163 participants, DOX (doxycycline) with 10 participants, and ATD (azithromycin followed by doxycycline) with 139 participants, further divided into treatment duration of less than or equal to 3 days (81 participants) and more than 3 days (58 participants). The second panel displays a bar chart of defervescence within 48 hours among the groups. The third panel shows a bar chart of medical resource utilization rates. The fourth panel compares oxygen therapy rates after 1:1 propensity score matching, showing 44% in the DOX+ATD1 group and 78% in the ATD2 group.

Study groups and key outcomes.