Concentrations of gatifloxacin in plasma and pulmonary compartments following a single 400 mg oral dose in patients undergoing fibre-optic bronchoscopy.

The concentrations of gatifloxacin achieved after a single 400 mg oral dose were measured in plasma, epithelial lining fluid (ELF), alveolar macrophages (AMs) and bronchial mucosa (BM) using a microbiological assay. Fourteen patients undergoing fibre-optic bronchoscopy were studied. Mean plasma, ELF, AMs and BM concentrations, respectively, at 2, 4 and 12 h were as follows: 2 h: 3.96 mg/L, 6.00 mg/L, 69.10 mg/L, 6.24 mg/kg; 4 h: 3.22 mg/L, 6.16 mg/L, 77.32 mg/L, 5.32 mg/kg; 12 h: 1.74 mg/L, 2.98 mg/L, 61.95 mg/L, 3.00 mg/kg. These concentrations exceed the MIC(90)s for common respiratory pathogens such as Streptococcus pneumoniae (0.5 mg/L), Haemophilus influenzae (0.013 mg/L), Moraxella catarrhalis (0.05 mg/L), Chlamydia pneumoniae (0.125 mg/L) and Mycoplasma pneumoniae (0.06 mg/L).