[en] The effect of bromhexine on mucociliary clearance mechanisms was evaluated in 10 patients with various chest diseases in stable condition by radioaerosol inhalation lung scintigraphy. Visual and numerical evaluations were made by radioaerosol inhalation lung cine-scintigraphy and by calculating the following 5 indices; i) lung retention ratio, ii) airway deposition ratio, iii) airway retention ratio, iv) airway clearance efficiency and v) alveolar deposition ratio, respectively. Lung function tests and chest roentgenograms were also performed before and after administration of bromhexine. Aerosol inhalation lung cine-scintigraphy did not reveal a very marked difference in mucus transport patterns on the trachea after administration of bromhexine, but numerical analysis showed significantly smaller lung and airway retention ratios and greater airway clearance efficiencies, whereas airway deposition ratios remained unchanged in the first 80 min, indicating a more efficient airway mucus clearance after bromhexine administration. (author)