In vitro antimicrobial activity of cefpirome and its therapeutic efficacy in respiratory infections

We measured the in vitro antimicrobial activity of cefpirome (CPR), a new semisynthetic cephalosporin agent for parenteral use, and evaluated its therapeutic efficacy in respiratory infections. T|he minimum inhibitory concentrations MICs) of CPR. ceftazidime (CAZ) and latamoxef (LMOX = moxalaetam) against 20 strains each of Staphylococcus aureus. Escherichia coli, Klebsiella pneumoniae, Enterobacter cloacae, Serratia marcescens and Pseudomonas aeruginosa were determined by a micro-broth dilution method using the Dynatech MIC-2000 system. As shown by the MICs, CPR was the most active against 5. aureus and Enterobacteriaceae of the three agents tested, but it was somewhat less active than CAZ against P. aeruginosa. A daily dose of 2 g of CPR was given intravenously for 6-36 days (mean: 20.0 days) to 5 patients: 3 with acute pneumonia. 1 with empyema and 1 with pulmonary tuberculosis. The clinical efficacy was good in three and fair in one. One case of pulmonary tuberculosis had to be excluded from clinical evaluation. Two strains of S. aureus were identified as causative organisms and both were eradicated by the administration of CPR. Drug induced fever and an elevated GOT and GPT were observed in two patients. Elevated BUN and thrombocytepenia were found, respectively, in one patient each. These adverse reactions disappeared after completion of the therapy. From the above results, we conclude that CPR is one of the most useful cephalosporin agents for parenteral use as a first choice in the treatment of respiratory infections.