Evaluation of efficacy and safety of erdosteine in patients affected by chronic bronchitis during an infective exacerbation phase and receiving amoxycillin as basic treatment (ECOBES, European Chronic Obstructive Bronchitis Erdosteine Study).

An international multicentric study was conducted with the aim of demonstrating that erdosteine improves the efficacy of amoxycillin in the treatment of infective exacerbation of chronic bronchitis mainly on the clinical symptomatology (primary objective), on spirometric tests and body temperature, without negatively influencing the tolerance (secondary objectives). The study was conducted as a prospective evaluation, with 2 comparative groups treated with erdosteine (300 mg x 2/day) or placebo in association with amoxycillin (1500 mg/day) for a maximum of 10 days. The design of the trial was double-blind and parallel group with 2 subgroups. The treatments have been assigned randomly to a population of chronic bronchitic patients in exacerbation phase of n = 237 subjects. The study was conducted according to the principles of the Declaration of Helsinki and its amendments (Hong Kong, September 1989). The primary end-point used to determine effectiveness in this study was the global clinical assessment (GCA) which was choosen as a general indication of activity with objective/subjective evaluation of the clinical picture. Secondary endpoints of efficacy are sputum parameters, functional signs of chronic obstructive bronchitis, spirometric tests and overall judgement of efficacy. Safety was evaluated with adverse drug reactions reporting, arterial blood pressure, heart rate and laboratory tests monitoring. The obtained values have been analyzed with two-way and factorial ANOVA, Least Squares Catmod-SAS, Wilcoxon and Chi-square tests. The number of patients included in the effectiveness analysis is of n = 226 subjects, due to the fact that 11 patients were lost due to different reasons. In term of results as far as the primary objective of the study was concerned, erdosteine resulted more active than placebo. The analysis evidenced a very significant difference for treatment, time and interaction time x treatment. No difference on the contrary was observed for center and the interaction center x treatment. Sputum volume, body temperature and spirometric parameters were not significantly influenced by both treatments. Viscosity, appearance as well as functional signs evidenced a modification over time in favour of erdosteine. As safety is concerned the majority of adverse events, both in the erdosteine and in the placebo group, were related to the gastrointestinal area. For erdosteine, of 9/17 side-effects, 3 were epigastralgias, 3 nauseas, 1 diarrhoea, 1 taste loss, 1 hemorrhoids. For placebo of 13/17 related events 3 were epigastralgias, 4 nauseas, 4 diarrhoeas, 1 pyrosis, 1 dry mouth. In terms of severity they have been all defined as mild or moderate degree. Also from a qualitative perspective it is clear that there are no relevant differences between the 2 treatments under evaluation, concerning safety. In conclusion of particular interest is the datum arising from the efficacy/safety evaluation, which indicates that the clinical picture is modified earlier and at deeper degree by the synergistic activity of erdosteine and of the antibiotic without the risk of an augmentation of side-effects incidence.