# Efficacy and safety of inhaled ambroxol solution in improving sputum of lower respiratory tract infection in children: a multicenter, randomized, double-blind, placebo-controlled trial

**Authors:** Baoping Xu, Peng Han, Yunxiao Shang, Huanji Cheng, Zhiying Han, Lin Zhao, Shaoru He, Min Lu, Enmei Liu, Kunling Shen

PMC · DOI: 10.1186/s12890-025-03845-0 · BMC Pulmonary Medicine · 2025-08-08

## TL;DR

This study found that inhaled ambroxol solution safely improves sputum symptoms in children with lower respiratory tract infections.

## Contribution

A multicenter trial demonstrating ambroxol's efficacy in reducing sputum symptoms in pediatric LRTIs.

## Key findings

- Ambroxol significantly reduced cough scores compared to placebo in children with LRTIs.
- Phlegm-sound scores improved more in the ambroxol group on days 1-3 of treatment.
- Ambroxol had fewer adverse events than placebo, with similar adverse reaction rates.

## Abstract

To evaluate the efficacy and safety of inhaled ambroxol solution in improving sputum of lower respiratory tract infections (LRTIs) in children.

This study was a randomized, double-blind, parallel-group, placebo-controlled, multicenter trial. The patients were administered inhaled ambroxol or a placebo twice a day for 7 days. And researchers collected efficacy and (or) safety indicators every day during the course.

A total of 236 children were randomly assigned to receive ambroxol or placebo (1:1). At all visit points after the medication, the mean difference of cough score with the baseline between the two groups was statistically significant (P < 0.05). Compared with the baseline, the phlegm-sound scores in the throat of the experimental group decreased more on the 1st, 2nd, and 3rd days after administration (P < 0.05). But there was no difference in pulmonary rale scores. The occurrence of adverse events in the experimental group was lower (21.37% vs. 35.59%, P = 0.021), and the incidence of adverse reactions was similar between the two groups (2.56% vs. 5.08%, P = 0.499).

Inhaled ambroxol solution could improve the sticky sputum symptoms in children with LRTIs and is safe in clinical application. Further research is needed to confirm these findings.

The study was retrospectively registered on June 14, 2023, at https://www.chictr.org.cn/ under the number ChiCTR2300072466.

## Linked entities

- **Chemicals:** ambroxol (PubChem CID 2132)

## Full-text entities

- **Diseases:** pulmonary rale (MESH:D012135), cough (MESH:D003371), LRTIs (MESH:D012141)
- **Chemicals:** ambroxol (MESH:D000551)
- **Species:** Homo sapiens (human, species) [taxon 9606]

## Full text

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## Figures

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## References

2 references — full list in the complete paper: https://tomesphere.com/paper/PMC12333169/full.md

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Source: https://tomesphere.com/paper/PMC12333169