Extracellular concentrations of fosfomycin in lung tissue of septic patients.

Objectives: The present investigation explored the ability of fosfomycin to penetrate lung tissue of septic patients by utilizing the microdialysis technique.

Methods: After microdialysis probe insertion into healthy and infected lung tissue, a single intravenous dose of 4 g of fosfomycin was administered.

Results: The mean C(max), T(max), AUC(0-4) and AUC(0-infinity) for healthy lung were 131.6 +/- 110.6 mg/L, 1.1 +/- 0.4 h, 242.4 +/- 101.6 mgxh/L and 367.6 +/- 111.9 mgxh/L, respectively. The corresponding values for infected lung were 107.5 +/- 60.2 mg/L, 1.4 +/- 0.5 h, 203.5 +/- 118.4 mgxh/L and 315.1 +/- 151.2 mgxh/L. The half-life of fosfomycin ranged from 2.2 to 2.7 h between compartments. The magnitude of lung tissue penetration, as determined by the ratios of the AUC(0-infinity) for lung to the AUC(0-infinity) for plasma, was 0.63 +/- 0.31 and 0.53 +/- 0.31 for healthy and infected lung, respectively.

Conclusions: We conclude that fosfomycin achieves antimicrobially effective concentrations in infected lung tissue.