[Aztreonam. Diffusion into bronchial mucus].

In a prospective study of antibiotics' diffusion into human bronchial mucus, we compared serum and mucus concentrations of aztreonam, a new beta lactam belonging to the monobactam group. Twenty patients were given aztreonam (1 g twice a day) for an acute purulent exacerbation of chronic bronchitis and divided into four groups according to the time of sampling (0.5, 1, 1.5 or 3 h). Samples were taken on the first and third treatment days. Antibiotic concentrations were assayed using agar diffusion and HPLC. Aztreonam concentrations were low, similar to those achieved with other beta lactams. According to the time sampling, levels ranged from 0.27 to 1 mg/l and 0.4 to 1.15 mg/l on the first and third treatment days respectively. Corresponding serum levels were 90 mg/l and 30 mg/l, respectively 30 mn and 3 h after dose ingestion.