Moxalactam, a novel
beta-lactam antimicrobial agent in which
oxygen has replaced
sulfur in the six-membered ring of the conventional cephem nucleus, has in vitro activity against almost all commonly isolated bacterial pathogens including Staphylococcus aureus, the Enterobacteriaceae, Pseudomonas aeruginosa, Bacteroides fragilis, and Haemophilus influenzae. The clinical efficacy an toxicity of
moxalactam alone was evaluated in the treatment of 100
infections, including 22
septicemias. Thirty-two
infections involved P aeruginosa, while organisms resistant to one or more of the currently available
cephalosporins or
cefoxitin were isolated from cultures in 63 of the cases. The overall clinical response was favorable (
infection cured or improved) in 86% of the
infections. A child with Klebsiella pneumoniae ventriculitis and
meningitis was cured with intravenous
moxalactam alone. Six of 14 treatment failures involved P. aeruginosa, and P aeruginosa isolates resistant to
moxalactam emerged during
therapy of 12
infections. Side effects, usually mild
diarrhea, occurred in only 8.8% of the patients. Except for some severe P aeruginosa
infections outside the urinary tract,
moxalactam is effective and safe single-agent
therapy for
infections caused by susceptible organisms and represents a major advancement in
beta-lactam antimicrobial
therapy.