Efficacy and safety of an extract of Pelargonium sidoides (EPs 7630) in adults with acute bronchitis. A randomised, double-blind, placebo-controlled trial

New evidence-based treatment options are required to avoid antibiotic overuse in acute bronchitis and to replace potentially inefficacious initial antibiotic treatment. To evaluate the efficacy and safety of an extract of Pelargonium sidoides (EPs 7630) compared to placebo in patients with acute bronchitis. Randomized, double-blind, placebo-controlled trial using a multi-stage adaptive design. 36 primary care physicians (investigators) at the out-patient care setting. 468 adults with acute bronchitis present < or = 48 hours, Bronchitis Severity Score (BSS) > or = 5 points, and informed consent. EPs 7630 or placebo (30 drops three times daily) for 7 days. The primary outcome criterion was the change of BSS on day 7. The decrease of BSS from baseline to day 7 was 5.9 +/- 2.9 points under EPs 7630 (n = 233), and 3.2 +/- 4.1 points under placebo (n = 235). The 95% CI for the difference of effects between the two treatment groups (EPs 7630 minus placebo) was calculated as [-3.359; -2.060] showing a significant superiority of EPs 7630 compared to placebo on day 7 (p < 0.0001). Working inability decreased to 16% in the EPs 7630 group compared to 43% in the placebo group (p < 0.0001). In addition, the duration of illness was significantly shorter for patients treated with EPs 7630 compared to placebo (p < 0.001). Within the first four days, onset of treatment effect was recognized in 53.6% of patients under EPs 7630 compared to 36.2% of patients under placebo, only (p < 0.0001). Adverse events (AEs) occurred in 36/468 patients (EPs 7630: 20/233 patients, placebo: 16/235 patients). All events were assessed as non-serious. EPs 7630 was superior in efficacy compared to placebo in the treatment of adults with acute bronchitis. Treatment with EPs 7630 clearly reduced the severity of symptoms and shortened the duration of working inability for nearly 2 days.