Concentrations of ceftibuten in bronchial secretions

Ceftibuten is a broad-spectrum oral cephalosporin exhibiting antimicrobial activity against a wide range of gram-negative and some gram-positive pathogens. Pharmacokinetic studies have shown that the molecule has an oral bioavailability higher than 90% of the administered dose (reaching peak serum concentrations of 5-19 mg/l after a single dose of 200 and 400 mg). Moreover, ceftibuten has been shown to be useful in the treatment of acute lower respiratory tract infections. This study was performed to determine the distribution of ceftibuten in bronchial secretions from patients affected by the exacerbation of chronic bronchitis. Patients were treated with a single 400-mg oral dose of ceftibuten. Blood and bronchial-secretion samples were obtained just before, and at 0.5, 1, 2, 4, 8, 12, 16 and 24 h after dosing. Cells were separated from bronchial secretions by centrifugation. Ceftibuten in duplicate samples of both serum and bronchial secretion was quantified by HPLC. Ceftibuten reached peak levels 2 and 4 h after oral administration in serum and in bronchial secretions, respectively (18.12 +/- 2.13 and 9.19 +/- 3.1 mg/l, respectively). Falling curves after the peaks showed a monoexponential decay. The absorption was very rapid both in serum and bronchial secretions, but elimination was slower in bronchial secretions than in serum.