The cooperation of cefotaxime and desacetyl-cefotaxime with respect to antibacterial activity and beta-lactamase stability.

Desacetyl-cefotaxime, the main metabolite of cefotaxime, possesses a broad antibacterial spectrum. Its activity is lower than that of cefotaxime, but significantly surpasses that of cefazolin against gram-negative bacteria. The beta-lactamase stability of desacetyl-cefotaxime is higher than that of the parent compound. This beta-lactamase stability might be responsible for the synergistic effects of cefotaxime and desacetyl-cefotaxime occasionally seen in in vitro combination studies.