[Penetration of mezlocillin into bronchial secretions (author's transl)].

The penetration of mezlocillin into bronchial secretions collected by fiberoscopy was determined in 18 hospital patients with acute-on-chronic bronchial infection. Samples of blood and bronchial mucus were collected simultaneously 3 hours after each 12-hourly intramuscular injection of 1 g mezlocillin. Antibiotic concentrations were measured by the microbiological method. Mezlocillin concentrations in bronchial secretions averaged 50 % of concomitant serum concentrations. The rate of penetration of the drug was higher than that observed with ampicillin in similar conditions. The mean bronchial level of 3 micrograms/ml was indicative of a high therapeutic index in relation to the MICs of the pathogens isolated in these patients. It is concluded that intramuscular mezlocillin is indicated for the treatment of acute exacerbations of chronic bronchial infections due to highly sensitive organisms.