Safety and efficacy of inhalable ambroxol hydrochloride aerosol for adult patients with respiratory diseases: an open-label, single-arm, multicentre study.

Background: Airway mucus hypersecretion is a key pathophysiological feature in many respiratory diseases and could lead to airway obstruction and repeated infections, consequently accelerating disease progression, which impacts on pulmonary function and quality of life (QoL), highlighting the importance of mucolytic therapy targeting airway mucus hypersecretion.

Objectives: To investigate the safety and efficacy of inhalable ambroxol hydrochloride aerosol for adult patients with respiratory diseases.

Design: An open-label, single-arm, multicentre postmarketing surveillance study.

Methods: Adult patients with acute or chronic respiratory diseases were eligible to receive aerosol inhalation of ambroxol hydrochloride (3 mL and 7.5 mg/mL) using a nebuliser two times per day given at least 6 hours apart between doses. The treatment lasted for a maximum of 7 days. The primary safety outcome was the frequency and severity of adverse events (AEs), and the primary efficacy outcome was changes in sputum scale scores.

Results: Among 1201 eligible patients, 1192 received study medication and were included in the full analysis set and the safety set. Any grade AEs occurred in 16.3% of the patients, including serious AEs in four (0.3%) patients. The three most frequent AEs were respiratory symptoms and signs (1.5%), nausea and vomiting (0.8%) and digestive tract symptoms and signs (0.7%). In the full analysis set, the patients showed a mean reduction of 77.6% (95% CI, 75.9% to 79.3%) in the sputum scale score at the end of treatment, with a mean difference of -1.7±0.7 from baseline (p<0.001).

Conclusion: Inhalable ambroxol hydrochloride aerosol is well tolerated and effective in easing expectoration and alleviating cough, reducing sputum and improving the QoL of adult patients with acute and chronic respiratory diseases.

Trial registration number: ChiCTR2100043736.