Placebo found Equivalent to Amoxicillin for Treatment of Acute Bronchitis in Nairobi, Kenya: A Triple-Blind Randomized Equivalence Trial

Abstract

Background: Antibiotic treatment is not recommended for acute bronchitis in immunocompetent patients in industrialized countries. Whether these recommendations are relevant to the developing world and to immunocompromised patients is unknown.

Methods: Randomized triple-blind placebo-controlled equivalence trial of amoxicillin vs. placebo in 660 adults presenting to two outpatient clinics in Nairobi, Kenya with acute bronchitis but without evidence of chronic lung disease. The primary study endpoint was clinical cure as defined by a  75% reduction in a validated acute bronchitis severity score (ABSS) 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 randomized 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 hospitalization or died.

Conclusions: Antibiotic treatment of acute bronchitis is unhelpful, even in populations with a high prevalence of HIV infection.