Steady-state moxalactam kinetics: comparisons with other cephalosporins

Moxalactam is a new beta-lactam antimicrobial with an extended spectrum. Serum concentrations were determined in 14 patients at steady state using bioassay and high-pressure liquid chromatography methods. Mean peak and trough serum concentrations were 195 and 29.5 micrograms/ml for the 20-gm dose and 214 and 28.8 micrograms/ml for the 3-gm dose. Peak and trough levels exceeded the minimum inhibitory concentration of the infecting bacteria in 100% and 67% of the patients. The 3-gm dose is recommended for infections caused by Pseudomonas aeruginosa and other organisms with higher minimum inhibitory concentrations. Half-lifes ranged from 1.7 to 5.7 hr and reflected the varying renal functions of the patients. A relationship (r = 0.878, p less than 0.001) between creatinine clearance and elimination rate constant was established by bivariant linear regression analysis.