ABSTRACT
Cefotaxime is one of two third-generation cephalosporins (the other being ceftriaxone) that undergo significant metabolism and is the only third-generation cephalosporin for which an active metabolite has been identified. Cefotaxime was administered intravenously in doses of 6 g per day to 20 patients with serious infections of the lower respiratory tract due to organisms susceptible to cefotaxime (isolates of Enterobacteriaceae and of Pseudomonas aeruginosa). It was administered with gentamicin in some high-risk patients. Cefotaxime resulted in mean peak concentrations of 32 mu/ml (cv% = 53) and of 29.5 micrograms/ml (cv% = 65) respectively after the first and after the last dose of a regimen of 2 g every 8 hours. The half-life value averaged 1.8 h and 6.4 h for cefotaxime and its desacetyl metabolite respectively. The average value of the metabolite at the end of short infusion was 11.5 micrograms/ml (cv% = 31) after the initial dose and 15.5 micrograms/ml (cv% = 37) after the last administered dose. Overall results were 75% patients cured or improved; 83% of the patients with nosocomial pulmonary infections due to Enterobacteriaceae were cured; 50% of the patients with Pseudomonas aeruginosa infections were cured and 25% improved despite the pathogen not being eradicated. No serious toxicity was observed.
