Serum Bactericidal Activities of Mezlocillin and Mezlocillin/sulbactam: A Comparative Study

OBJECTIVE To determine the serum bactericidal activities(SBAs) of mezlocillin(MLXL) and mezlocillin/sulbactam(MLBJ) against clinical isolates. METHODS A randomized self control clinical study was performed in 10 healthy male volunteers, 3.75 g or 3.0 g was administered by iv. To contrast the SBAs of both them, the blood samples were taken in 0.5 h and 7 h after administration. RESULTS The peak SBAs of MLBT against β lactamase positive Staphylococcas aureus, S. epidermidis, Enterococcus cloacae, Escherichia coli were higher than mezlocillin by 2 4 times. The peak SBAs of MLBT against ESBLs positive Klebsiella pneumoniae and E.coli were slightly stronger than MLXL by 1 2 times. There was no significant difference against Pseudomonas aeruginosa between MLBT and MLXL. CONCLUSIONS In vivo the antibacterial activities of MLBT against clinical β lactamase positive isolates are stronger than MLXL.