In vitro antimicrobial activity and therapeutic efficacy of cefluprenam in the treatment of respiratory tract infections

The in vitro antimicrobial activity of cefluprenam (CFLP), a novel perenteral cephalosporin developed in japan, and its therapeutic efficacy in the treatment of respiratory tract infections were evaluated. The minimum inhibitory concentrations (MICs) of CFLP, cefpirome (CPR), ceftazidime (CAZ) and flomoxef (FMOX) against a total of 138 strains consisting of six different species : methicillin-susceptible Staphylococcus aureus (MSSA), methicillin-resistant Staphylococcus aureus (MRSA), Escherichia coli, Klebsiella pneumoniae, Enterobacter cloacae, Serratia marcescens and Pseudomonas aeruginosa were determined by the micro - broth dilution method using the Dynatech MIC 2000 system. As shown by MICs, CFLP was more active than reference antibiotics against MSSA, MRSA, E. cloacae and P. aeruginosa. CFLP was more active than CAZ, and as active as CPR and FMOX against E.coli and K. pneumoniae. Against S.marcescens CFLP was more active than CAZ, but less active than CPR. A dose of 1g (12 cases) and 2g (3 cases) respectively of CFLP was given daily to a total of 15 patients for 4 to 14 days (mean : 11.2 days): 4 patients with pneumonia, 8 patients with infection associated with bronchiectasis, and one patient each with lung abscess, diffuse panbronchiolitis and infection associated with lung cancer. The clinical effects were excellent in one patient, good in nine patients, fair in one patient and poor in three patients (efficacy rate: 71.4%). One case was excluded from clinical evaluation because signs and symtoms of infection were not clear. Six strains were identified as causative organisms : Two strains of P. aeruginosa and one strain each of Streptococcus pneumoniae, Moraxella catarrhalis, Heamophilus influenzae and E. coli. CFLP eradicated all of them except for one strain of P. aeruginosa. Drug fever, drug exanthema et elevation of s-GPT as well as leucocytopenia, elevation of LAP, and a decrease of Hb et Ht were observed in one patient each. All of these adverse effects disappeared after completion of therapy. From the above results, we conclude that CAZ is a useful antibiotic for parenteral use as a first choice in the treatment of respiratory tract infections.