Intrapulmonary penetration of linezolid.
OBJECTIVE
This study was designed to measure the concentrations of linezolid in bronchial mucosa, pulmonary macrophages and epithelial lining fluid and to compare them with simultaneous blood levels.


METHODS
Ten adult patients undergoing bronchoscopy for diagnostic purposes were given oral linezolid at a dosage of 600 mg twice a day for a total of six doses. Patients with active lung infection were excluded from the study. Flexible bronchoscopy was carried out between 2 and 8 h after the last dose of linezolid. Bronchial biopsies and bronchoalveolar lavage were carried out and a simultaneous blood sample obtained. Linezolid levels were measured using high-performance liquid chromatography (HPLC).


RESULTS
Mean concentrations of linezolid were 13.4 mg/L in serum, 10.7 mg/kg in mucosa, 8.1 mg/L in alveolar macrophages and 25.1 mg/L in epithelial lining fluid. The mean site/serum concentration ratios were 0.79 for bronchial mucosa, 0.71 for macrophages and 8.35 for epithelial lining fluid.


CONCLUSIONS
The MIC90 (< or =4 mg/L) of linezolid for Staphylococcus aureus and Streptococcus pneumoniae was exceeded in serum and bronchial mucosa in all subjects, in epithelial lining fluid in nine subjects and in macrophages in six subjects.
Honeybourne
David
D
Department of Respiratory Medicine, Birmingham Heartlands Hospital, Bordesley Green East, Birmingham B9 5SS, UK. david.honeybourne@heartsol.wmids.nhs.uk
Tobin
Caroline
C
Jevons
Gail
G
Andrews
Jenny
J
Wise
Richard
R
D000081:Acetamides / Q000378:metabolism / Q000493:pharmacokinetics*; D000328:Adult; D000368:Aged; D001999:Bronchoscopy / Q000379:methods; D005260:Female; D006801:Humans; D000069349:Linezolid; D016676:Macrophages, Alveolar / Q000378:metabolism; D008297:Male; D008826:Microbial Sensitivity Tests / Q000379:methods; D008875:Middle Aged; D023303:Oxazolidinones / Q000378:metabolism / Q000493:pharmacokinetics*; D020545:Respiratory Mucosa / Q000378:metabolism*
D000081:Acetamides; D023303:Oxazolidinones; D000069349:Linezolid