Placebo found equivalent to amoxicillin for treatment of acute bronchitis in Nairobi, Kenya: a triple blind, randomised, equivalence trial

Background: Antibiotic treatment is not recommended for acute bronchitis in immunocompetent patients in industrialised countries. Whether these recommendations are relevant to the developing world and to immuno-compromised patients is unknown. Design, setting and participants: Randomised, triple blind, placebo controlled equivalence trial of amoxicillin compared with placebo in 660 adults presenting to two outpatient clinics in Nairobi, Kenya, with acute bronchitis but without evidence of chronic lung disease. Main outcome measure: The primary study end point was clinical cure, as defined by a >= 75% reduction in a validated Acute Bronchitis Severity Score by 14 days; analysis was by intention to treat with equivalence defined as <= 8% difference between study arms. Results: Clinical cure rates in the amoxicillin and placebo arms were 81.7% and 84.0%, respectively (difference 2.3%, 95% CI -8.6% to 4.0%). Of 131 HIV infected subjects (19.8%), cure rates for those randomised to amoxicillin (77.2%) and placebo (83.8%) differed by 6.6% (95% CI -21.7% to 8.6%). Among HIV uninfected subjects, the difference in cure rates was 1.6% (95% CI -8.5% to 5.3%). Potential drug side effects were similar in the two arms. No subjects required hospitalisation or died. Conclusion: Antibiotic treatment of acute bronchitis is unhelpful, even in populations with a high prevalence of HIV infection.