Basic and clinical studies on cefdinir

We performed basic and clinical studies on cefdinir (CFDN), a new cephalosporin antibiotic, with the following results. 1. Antimicrobial activity The MIC₈₀ of CFDN against various clinical isolates was as follows: 0.78 μg/ml against Staphylococcus aureus, 12.5 μg/ml against Enterococcus faecalis, 0.39 μg/ml against Escherichia coli, 0.78 μg/ml against Klebsiella pneumoniae, >100 μg/ml against Enterobacter spp., 50 μg/ml against Serratia marcescens, 0.78 μg/ml against Proteus mirabilis, 12.5 μg/ml against Proteus vulgaris, 100 μg/ml against Citrobacter spp. and>100 μg/ml against Psedomonas spp. The activity of CFDN against Gram-postive cocci was 3-4 times stronger than that of cefaclor (CCL), and 5-6 times stronger than that of cefixime (CFIX). The activity against E. coli, K. pneumoniae and Citrobacter spp. was about the same as that of CFIX, and against other Gram-negative bacilli it was less than that of CFIX. On the other hand, the activity of CFDN was much stronger than that of CCL. 2. Clinical efficacy One patient with pneumonia, 18 with bronchitis, 5 with tonsillitis or pharyngitis, 4 with pyelonephritis, 3 with cystitis, 1 with prostatitis, and 1 with thrombophlehitis were treated with CFDN in a daily dose of 200-600 mg for 2-32 days. Clinical response was excellent in 5 patients, good in 18, fair in 8, poor in 1 and unknown in 1. The clinical efficacy rate was 71.9%. CFDN was more effective in acute upper respiratory tract infections, pneumonia, and urinary tract infections. As for adverse reactions, diarrhea or loose stool were noted in 2 patients. As abnormal laboratory data, eosinophilia was seen in 2 patients, and elevated GOT and GPT or GPT alone were observed in 2.