Pharmacokinetics and bacteriological efficacy of moxalactam (LY127935), netilmicin, and ampicillin in experimental gram-negative enteric bacillary meningitis

Moxalactam (LY127935) is a 1-oxa-β-lactam which was active in vitro against the majority of 128 strains of gram-negative enteric bacilli isolated from meningitis in neonates. Pharmacokinetics and bacteriological efficacy of LY127935 were studied in a lapin meningitis model. The average penetration of this investigational oxa-cephalosporin into cerebrospinal fluid of infected rabbits was 23% compared with 25% for netilmicin and 11% for ampicillin. The cerebrospinal fluid concentrations of LY127935 produced median bactericidal titers of 1:64 to 1:128 against five coliform organisms (two Escherichia coli K1 strains, Klebsiella pneumoniae, Salmonella saint-paul, and Citrobacter diversus) used in these experiments compared with median titers of 1:2 to 1:8 for netilmicin and 1:2 to 1:4 for ampicillin. LY127935 was statistically significantly more effective than netilmicin or ampicillin in reducing cerebrospinal fluid bacterial colony counts and in sterilizing cerebrospinal fluid of experimentally infected rabbits. These results suggest that LY127935 has theoretical advantages over netilmicin and ampicillin for therapy of gram-negative bacillary meningitis.