A STUDY ON IN VITRO ANTIBACTERIAL ACTIVITY AND CLINICAL USEFULNESS IN RESPIRATORY TRACT INFECTIONS OF PANIPENEM/BETAMIPRON, A NEWLY SYNTHESIZED CARBAPENEM ANTIBIOTIC

Abstract

Panipenem/betamipron (PAPM/BP) is a combination drug of PAPM, a new parenteral carbapenem antibiotic and BP, an amino acid derivative at a weight ratio of 1:1.
Its in vitro antibacterial activities against clinically isolated respiratory pathogenic bacteria were determined. It was superior to imipenem (IPM) in the in vitro antibacterial activities against Haemophilus influenzae, Haemophilus parainfluenzae, Branhamella catarrhalis, Staphylococcus aureus including MRSA, Klebsiella pneumoniae, Serratia marcescens and Escherichia coli. PAPM had antibacterial activities almost equal to those of IPM against Streptococcus pneumoniae and Enterococcus spp. Against Pseudomonas aeruginosa, however, its antibacterial activity was about 1/4 that of IPM.
The clinical usefulness of PAPM/BP was studied by dissolving it in a solution containing lactate and administering the solution by intravenous drip infusion to 12 cases of respiratory tract infections.
Out of 11 cases with respiratory tract infections excluding cytomegalovirus pneumonia, the efficacy rate was 90.9%, with 4 cases of excellent and 6 cases of good responses.
In terms of its bacteriological efficacies, eradications of pathogenic bacteria including superinfection were observed in 2 out of 4 strains, but 2 strains of P. aeruginosa remained unchanged. Six strains appeared as superinfected bacteria during and after administration of this preparation substituting original pathogens.
Side-effects were not observed in the 12 cases, and in laboratory tests, slight transient increases of S-GOT and S-GPT were found in 1 case.
In conclusion, PAPM/BP is a very useful parenteral antibiotic against respiratory tract infections and can be one of the drugs of the first choice.