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.
Keywords: antitussive agents; cough; dextromethorphan; honey; ipratropium; randomized controlled trial.
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.
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