Sputum and blood concentrations of cefuroxime in lower respiratory tract infection.

A detailed pharmacokinetic study of cefuroxime has been carried out. Levels of cefuroxime were determined in the blood, sputum, saliva, and urine of 23 patients receiving parenteral cefuroxime eight hourly for chest infections. Profiles were obtained after the first dose and on the final (fifth) day of treatment. Antibiotic levels in the sputum reached 0.8 mg/l within one hour of the first injection, and were maintained close to this value for six hours. There was a build-up by the fifth day, mean cefuroxime concentrations at this time reaching 1.8 mg/l. This concentration was maintained for a prolonged period. Salivary concentrations were detectable but low (maximum mean value was 0.6 mg/l). Concentrations of antibiotic were significantly higher in the serum than those observed after the same doses in volunteers. In the patients there was no build-up in serum levels between the first and fifth days. The data obtained explain the clinical efficacy of cefuroxime in the treatment of lower respiratory infections, and suggest that a 12-hour schedule may be feasible.