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

Lay Summary Cough is the most frequent symptom reported by patients with lower respiratory tract infections. Despite being a defense mechanism, cough is unpleasant and negatively affects sleep and overall well-being. Accordingly, many patients with acute cough seek medical help to mitigate symptoms and reduce their duration despite the typically self-limiting nature of the condition. In this randomized clinical trial, we explored the benefit of 3 common symptomatic treatments recommended in some guidelines for relieving this symptom during the course of uncomplicated acute bronchitis, a cough suppressant, an inhaler, and honey intake. Although the total number of patients initially expected could not be achieved due to the disruption caused by the COVID-19 pandemic, the results of our study demonstrate a lack of efficacy of these products as the number of days of severe-to-moderate cough was similar in the 3 arms and comparable to the group of patients allocated to usual care. 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 mu g 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.