Antimicrobial activity and clinical efficacy of biapenem

Abstract

The antimicrobial activity and clinical efficacy of biapenem (BIPM), a new carbapenem, were investigated and following results were obtained.
1) Antimicrobial activity: The activity of BIPM was investigated using an inoculum size of 10⁶ cfufml against 404 clinically isolated strains of 25 species including Staphylococcus aureus, Staphylococcus epidermidis, Coagulase negative Staphylococcus, Streptococcus pneumoniae, Streptococcus pyogenes, Streptococcus agalactiae, Enterococcus faecalis, Esherichia coli, Salmonella spp., Klebsiella pneumoniae, Proteus vulgaris, Proteus mirabilis, Serratia marcescens, Citrobacter freundii, Enterobacter cloacae, Providencia stuartii, Pro videncia alcahfaciens, Pseudomonas aeruginosa, Xanthomonas maltophilia, Branhamella catarrhalis, Haemophilus influenzae, Acinetobacter calcoaceticus, Vibrio parahaemolyticus, Vibrio fluvialis and Vibrio alginolyticus, and compared with those of imipenem (IPM).
BIPM and IPM showed potent activity against gram-positive cocci except for methicillin resistant S. aureus, but the activity of BIPM was somewhat inferior to IPM in general. Both showed excellent activity against every strain of Enterobacteriaceae and other gram-negative bacteria, except for X. maltophilia and H. influenzae. But against the strains of Proteus spp., the activity of BIPM was inferior to IPM.
2) Clinical efficacy: Two patients with liver abscess, 8 with pneumonia and one with chronic bronchitis were treated twice a day with BIPM at a dose of 150-300mg by drip infusion for 4 to 25 days. The clinical response was excellent in 3 cases of pneumonia and one of chronic bronchitis, and good in remaining cases with pneumonia. As to the cases with liver abscess clinical efficacies were not observed. As for isolated strains from respiratory tract infection cases, 2 strains of S. pneumoniae and each one of P. aeruginosa and Haemophilus parainfluenzae were eradicated. K. pneumoniae and K. oxytoca, isolates from the cases with liver abscess, were also eradicated in spite of their insufficient clinical responses. Though no subjective adverse reaction was observed, slight elevation of serum transaminase value occurred in two cases.