Moxalactam in Serious Infections: Clinical, Bacteriologic, and Pharmacokinetic Studies

Moxalactam was evaluated in vitro against 600 nosocomial isolates of gram-negative bacteria and was compared with cephalothin, cefoxitin, and cefotaxime. Moxalactam was superior to the other compounds, with minimal inhibitory concentrations of ≤4 μg/ml for 95% of the Enterobacteriaceae isolates and ≤8 μg/ml for 85% of the Bacteroides fragilis isolates; 70% of the Pseudomonas aeruginosa isolates were inhibited with ≤16 μg/ml. Moxalactam at doses ranging from 1 g every 12 hr to 2 g every 8 hr was given to patients with serious infections of the respiratory (14) or urinary (13) tract, abdominal abscess (4), osteomyelitis (4), meningitis (5), soft-tissue phlegmon (3), malignant external otitis (2), peritonitis (1), and panophthalmitis (1). The clinical response was excellent in 35 (74.5%) and improved in 12 (25.5%) of the 47 patients. The pathogen was eradicated in 29 (61.7%) patients, two patients had relapses, and bacteria persisted but in decreased numbers and without development of resistance in 16 patients. The half-life of moxalactam was 146 (± 21) and 125 (± 34) min after 2-g intravenous and 1-g intramuscular doses, respectively. Kinetic studies in sputum, bile, bone, aqueous humor, prostatic fluid, and cerebrospinal fluid showed moxalactam concentrations several times higher than the required MICs. No appreciable adverse effects or toxicity were observed.