Laboratory and clinical studies on cefpirome

We performed laboratory and clinical studies on cefpirome (CPR), a new injectable cephem antibiotic, with the following results. 1. Antibacterial activity The MICs of CPR against various clinical isolates were determined with an inoculum size of 10⁶ cells/ml. The MIC₈₀ was 3.13 µg/ml for Staphylococcus aureus, 25 µg/ml for Enterococcus faecalis, 0.10 µg/ml for Escherichia coli, Klebsiella pneumoniae, Enterobacter aerogenes and Proteus mirabilis, 0.39 µg/ml for Serratia marcescens, 0.78 µg/ml for Enterobacter cloacae and Proteus vulgaris, 1.56 µg/ml for Citrobacter spp. and 50 µg/ml for Pseudomonas aeruginosa. It was also found that, compared with the control drugs, cefotaxime, ceftazidime and cefoperazone, CPR showed superior activity against many kinds of bacteria. 2. Clinical results A total of 11 patients (5 with pneumonia. 2 with acute bronchitis. 1 with chronic bronchitis, 1 with pyelonephritis and 1 with fever of unknown origin) were treated with CPR at a daily dose of 2 g for 5-20 days. Clinical response was excellent in 1 patient, good in 7. fair in 2 and poor in 1. No side-effects were observed, but eosinophilia was noted in three patients. From the above results, we consider that CPR is one of the most useful antibiotics for the treatment of infectious diseases.