Effect of ambroxol on the concentration of cefotaxime in the bronchoalveolar lavage fluid of rats with pulmonary fibrosis

This study aimed to investigate the effect of ambroxol on the concentration of cefotaxime in the bronchioalveolar lavage fluid of rats with bleomycin-induced pulmonary fibrosis. A total of 54 Wistar male rats were randomly divided into three groups, namely the normal control group, model group and ambroxol group. On experimental day 0, the rats were intratracheally instilled with bleomycin (5 mg/kg body weight) or sterile saline. The rats in the ambroxol group were then treated with ambroxol (35 mg/kg/day) intraperitoneally. On days 7, 14, 28 after instillation, six rats from each group were sacrificed, bronchial alveolar fluids were recovered and the lungs were collected for histopathological examination following the injection of cefotaxime (600 mg/kg) intravenously. The concentration of cefotaxime in the bronchial alveolar fluids was assayed by a liquid chromatography-mass spectrometry method. On day 7, the concentration of cefotaxime in the bronchial alveolar fluid of the ambroxol group was lower than that of the model group. On day 14, the concentration of cefotaxime in the bronchial alveolar fluids of the ambroxol group was higher than that of the model group, and the difference between these groups was significant statistically (P<0.001). On day 28, the concentration of cefotaxime in the bronchial alveolar fluids of the ambroxol group decreased sharply, and was lower than that of the model group (P=0.126). These results indicate that ambroxol increased the concentration of cefotaxime in the bronchial alveolar fluids at the primary fibrosis stage.