Objective To evaluate the efficacy of oral anti-inflammatory or antibiotic treatment compared with placebo in the resolution of cough in patients with uncomplicated acute bronchitis and discoloured sputum.
Design Multicentre, parallel, single blinded placebo controlled, randomised clinical trial.
Setting Nine primary care centres in Spain.
Participants Adults aged 18 to 70 presenting symptoms associated with respiratory tract infection of less than one week’s duration, with cough as the predominant symptom, the presence of discoloured sputum, and at least one other symptom of lower respiratory tract infection (dyspnoea, wheezing, chest discomfort, or chest pain).
Interventions Patients were randomised to receive either ibuprofen 600 mg three times daily, amoxicillin-clavulanic acid 500 mg/125 mg three times daily, or placebo three times daily for 10 days. The duration of symptoms was measured with a diary card.
Main outcome measure Number of days with frequent cough after the randomisation visit.
Results 416 participants were randomised (136 to ibuprofen, 137 to antibiotic, and 143 to placebo) and 390 returned their symptom diaries fully completed. The median number of days with frequent cough was slightly lower among patients assigned to ibuprofen (9 days, 95% confidence interval 8 to 10 days) compared with those receiving amoxicillin-clavulanic acid (11 days, 10 to 12 days) or placebo (11 days, 8 to 14 days), albeit without statistically significant differences. Neither amoxicillin-clavulanic acid nor ibuprofen increased the probability of cough resolution (hazard ratio 1.03, 95% confidence interval 0.78 to 1.35 and 1.23, 0.93 to 1.61, respectively) compared with placebo. Adverse events were observed in 27 patients, and were more common in the antibiotic arm (12%) than ibuprofen or placebo arms (5% and 3%, respectively; P<0.01).
Conclusion No significant differences were observed in the number of days with cough between patients with uncomplicated acute bronchitis and discoloured sputum treated with ibuprofen, amoxicillin-clavulanic acid, or placebo.
Trial registration Current Controlled Trials ISRCTN07852892.