Cefotaxime and desacetyl cefotaxime in human bile.

In a previous paper we reported on the determination of cefotaxime and desacetyl cefotaxime in human and rat serum after an i.v. injection of this cephalosporin (1); the concentrations of the parent compound and its metabolite in human bile were also briefly described. It has been shown that older cephalosporins with a 3~ acetoxymethyl substituent, e. g. cephalothin, are metabolised to the respective desacetyl compounds (2). The degradation of cefotaxime to desacetyl cefotaxime has also been observed in man and was simultaneously reported from other laboratories (3, 4). The purpose of this paper is to report in detail on the concentrations of cefotaxime and its antimicrobially active metabolite in human bile, measured both by high performance liquid chromatography (HPLC) and by bioassay with a selective test organism after an i.v. injection of 2 g.