CONCENTRATIONS OF LEVOFLOXACIN (HR-355) IN THE RESPIRATORY-TRACT FOLLOWING A SINGLE ORAL DOSE IN PATIENTS UNDERGOING FIBEROPTIC BRONCHOSCOPY

Concentrations of levofloxacin were measured in bronchial biopsies, al veolar macrophages (AM), epithelial lining fluid (ELF) and serum follo wing a single oral dose. Concentrations were measured by a microbiolog ical assay method. A total of 35 patients undergoing fibre-optic bronc hoscopy were studied. Mean serum, AM, ELF and biopsy concentrations we re as follows. 0.5 h: 4.73 mg/L, 19.1 mg/L, 4.74 mg/L and 4.3 mg/kg; 1 h: 6.6 mg/L, 32.5 mg/L, 10.8 mg/L and 8.3 mg/kg; 2 h: 4.9 mg/L, 41.9 mg/L, 9.0 mg/L and 6.5 mg/kg; 4 h: 4.1 mg/L, 27.7 mg/L, 10.9 mg/L and 6.0 mg/kg; and 6-8 h: 4.0 mg/L, 38.4 mg/L, 9.6 mg/L and 4.0 mg/kg resp ectively. Mean serum and AM concentrations at 12-24 h were 1.2 and 13. 9 mg/L respectively (concentrations in biopsy and ELF were only measur able in three of the six patients). These concentrations exceed the MI C(90)s of the common respiratory pathogens, Haemophilus influenzae (0. 015 mg/L), Moraxella catarrhalis (0.06 mg/L) and Streptococcus pneumon iae (1 mg/L) and suggest that levofloxacin should be efficacious in th e treatment of community- and hospital-acquired respiratory infection.