Penetration of ceftazidime into bronchial secretions in critically ill patients

Five adult patients admitted to ICU, with respiratory failure, required endotracheal intubation and respiratory support. They were treated with ceftazidime because of lower respiratory tract infections. All patients were given ceftazidime at 1, 2 and 3 g dosages in a randomized sequence and timed serum and bronchial secretion samples collected. Mean peak serum concentrations of 60.3, 148.7 and 224.8 mg/L were found in the three treatment groups and mean trough levels of 1.02, 1.85 and 1.63 mg/L respectively. Ceftazidime appeared rapidly in bronchial secretions reaching mean maximal concentrations of 2.2, 4.81 and 5.69 mg/L in the first sampling period (0-2 h). Serum and bronchial secretions AUCs have been calculated showing that both almost doubled their values between 1 and 2 g dosing, while between 2 and 3 g doses only a moderate and non-significant increase were found. On the basis of these results, the existence of a saturable transport mechanism for ceftazidime from serum to bronchial secretions can be postulated.