In vitro activity and clinical pharmacology of cefamandole in comparison to cephalothin

The in vitro activity of cefamandole and cephalothin were compared. Cefamandole was more active than cephalothin against 78% of all Gram-negative bacteria. Cefamandole also inhibited some strains of Enterobacter aerogenes, Enterobacter cloacae, Yersinia enterocolitica, Proteus rettgeri and Proteus morganii which were completely resistant to cephalothin. Clinical pharmacology of cefamandole and cephalothin was studied in ten healthy volunteers. One-half and 1 h after i.v. injection of 1 g, serum levels of cefamandole were five times higher than those of cephalothin. The half-life averaged 63 min for cefamandole and 27 min for cephalothin. Cefamandole was apparently metabolized less in the body than cephalothin. Skin blister fluid at the same time contained 4.5 μg cefamandole/ml. versus 1.5 μg cephalothin/ml. Protein binding was 67% for cefamandole and 70% for cephalothin.