Influence of a fluidifying agent (bromhexine) on the penetration of antibiotics into respiratory secretions.

The authors report the results of a study designed to evaluate the possible increase of penetration into bronchial secretions of antibiotics when combined with a fluidifying agent: bromhexine. The study was carried out in a double-blind experiment: erythromycin in 22 patients (group I) or amoxycillin in 26 patients (group II) were administered orally; in both groups several patients were given a placebo, instead of bromhexine. Antibiotics were administered at the usual dosage: 0.5 g X 2 for erythromycin (3 days); 1 g X 2 for amoxycillin (7 days); with the latter, two different doses of bromhexine were administered simultaneously: 48 mg/day and 96 mg/day in ten and eight patients respectively. Samples of bronchial secretions were collected by means of fibreoptic bronchoscopy at the second hour for erythromycin and for amoxycillin; simultaneous serum samples were also collected. The results of the study showed in both groups a significant increase of the ratios between bronchial levels and simultaneous serum concentrations when combined with bromhexine; in patients receiving amoxycillin with 96 mg of bromhexine the percentage penetration was noticeably higher (7.5%) than in those treated with 48 mg bromhexine (4.3%). These results confirm the efficacy of bromhexine as a drug able to disrupt mucopolysaccharides of bronchial secretions and, as a result, to increase the bronchial penetration of antimicrobial drugs as evaluated on the basis of percentage penetration ratio.