Abstract
The levels of levofloxacin (LVFX) in the serum, sputum and lung tissue were measured by a high-performanceliquid chromatography method, and the penetration ratio of LVFX into respiratory tissue was investigated.The subjects of this study were 23 patients under pulmonectomy or brochoscopy.
LVFX at the dose of 200 mg was given orally and specimens were collected as follows; serum at 2, 3 and 5hours after, sputum at 2 hours after, and lung tissue at 3 and 5 hours after the administration, respectively.The mean level of LVFX in lung tissue at 3 hours was 3.91±2.33 μg/g, and those in sputum and in serum at2 hours were 0.711±0.63 and 2.08±1.01μg/ml, respectively. A very strong correlation was demonstrated betweenthe level of LVFX in lung tissue and that in serum (p<0.0001), but correlation between those in sputum and inserum was not significant. The penetration ratio of LVFX into lung tissue was 217.2% and that into sputum was4.05%. Based on the results of this study, the breakpoints (BPs) of LVFX for pneumonia and chronic respiratorytract infections were calculated to be 4μg/ml and 1μg/ml, respectively.
It was concluded that penetration of LVFX into lung tissue was satisfactory, and the tissue level of LVFXexceeded greatly the MIC90s against the typical pathogenic bacteria of respiratory tract infections. Taking theexcellent BP for pneumonia, 4μg/ml, into consideration, it was thought that LVFX is an effective antibacterial agent against pneumonia and other respiratory tract infections.
