Serum and sputum concentrations of azlocillin, cefoperazone and ceftazidime in patients with cystic fibrosis.

Single-dose pharmacokinetics of azlocillin, cefoperazone and ceftazidime were studied in 17 patients with cystic fibrosis (CF). All patients had broncho-pulmonary infections caused by Pseudomonas aeruginosa. Three groups of five, six, and six patients were treated with azlocillin, cefoperazone, or ceftazidime, respectively. The size of the single dose was 133 mg/kg for azlocillin, 66.7 mg/kg for ceftazidime and 66.7 mg/kg for cefoperazone. The clearance values for the three antibiotics calculated from the single-dose data were, on the average, higher than the values previously reported for normal subjects. After the first dose, the patients received a repeated-dose treatment with the same antibiotic. During the first 5 days of therapy, a complement postural drainage of sputum was obtained four times a day for each patient. Cefoperazone could be measured in 47 (39.2%) of the 120 sputum samples assayed while ceftazidime was shown to be present in all 120 sputum samples examined. Azlocillin was not detected in any of the 100 sputum samples assayed.