[Bronchopulmonary penetration of enoxacin]

We analysed enoxacin concentrations in plasma, saliva, bronchial secretions, bronchoalveolar lavage fluid, and alveolar macrophages in nine patients five hours after the last dose (400 mg enoxacin b.i.d. per os for at least three days). The enoxacin levels in the alveolar film were extrapolated from the lavage content by using urea as an internal marker (lavage dilution factor = plasma/lavage urea concentration ratio). The concentration in the alveolar film amounted to 7.62 mg/l ( = 381% of the plasma value), on average, and exceeded the minimal inhibitory concentrations of the pathogens isolated from the patients. Thus, enoxacin is effectively concentrated in the surface film of the lung which represents an important barrier against pulmonary infections.