Effectiveness of antitussives, anticholinergics, and honey versus usual care in adults with uncomplicated acute bronchitis: a multiarm randomized clinical trial.

Background: Despite the frequent use of symptomatic therapies in cough, evidence of their benefits is lacking.

Objective: We compared the effectiveness of 3 symptomatic therapies and usual care in acute bronchitis.

Methods: Multicenter, pragmatic, multiarm parallel group, open randomized trial in primary care (ClinicalTrials.gov, Identifier: NCT03738917) was conducted in Catalonia. Patients ≥18 with uncomplicated acute bronchitis, with cough<3 weeks as the main symptom, scoring ≥4 in either daytime or nocturnal cough (7-point Likert scale), were randomized to usual care, dextromethorphan 15 mg t.i.d., ipratropium bromide inhaler 20 µg 2 puffs t.i.d, or 30 mg of honey t.i.d., all taken for up to 14 days. The main outcome measure was the number of days with moderate-to-severe cough. A symptom diary was given. A second visit was scheduled at days 2-3 for assessing evolution, with 2 more visits at days 15 and 29 for clinical assessment, evaluation of adverse effects, re-attendance, and complications.

Results: We failed to achieve the sample size scheduled due to the COVID-19 pandemic. We finally recruited 194 patients. The median number of days with moderate-to-severe cough (score ≥ 3) in the usual care arm was 5 (interquartile range [IQR], 4, 8.75), 5 in the ipratropium bromide arm (IQR, 3, 8), 5 in the dextromethorphan arm (IQR, 4, 9.75), and 6 in the honey arm (IQR, 3.5, 7). The same results were obtained in the Kaplan-Meier survival analysis for the median survival time of each arm with the usual care as the reference group.

Conclusion: The symptomatic treatment evaluated has shown to be ineffective against cough.