New Cephalosporin Antibiotic— Cephaloridine

CEPHALORIDINE, one of the new semisynthetic derivatives of cephalosporin C, is active against a wide variety of pathogenic microorganisms.¹⁻⁷Although cephaloridine is chemically related to sodium cephalothin (Keflin), the cephalosporin antibiotic currently in use in the United States, the modification in structure appears to offer some advantages. Results of preliminary studies indicated that cephaloridine possessed greater in vitro activity against some gram-positive strains than sodium cephalothin, consistently demonstrated higher and more sustained antibacterial levels in the blood, and was better tolerated following intramuscular administration⁸⁻¹¹(and according to written communication from R. S. Griffith, July 1965). This report deals with use of cephaloridine in 86 hospitalized patients treated for a variety of severe infections, and describes its in vitro effects against common bacterial pathogens. Materials and Methods Laboratory Studies. —Minimal inhibitory concentrations (MIC) and minimal bactericidal concentrations (MBC) of cephaloridine and sodium cephalothin were determined with 50 strains each