Basic and clinical studies on cefetamet pivoxil

We performed basic and clinical studies on cefetamet pivoxil (CEMT-PI), a new oral cephalosporin antibiotic, with the following results. 1) Antimicrobial activity The MICs of cefetamet (CEMT), the active substance of CEMT-PI, against various clinical isolates were determined with an inoculum size of 106cells/ml. The MIC₅₀ was 50 μg/ml for Staphylococcus aureus, >100 for Enterococcus faecalis, 0.78 for Escherichia coli, 0.39 for Klebsiella pneumoniae, 6.25 for Enterobacter cloacae, 0.78 for Enterobacter aerogenes, 1.56 for Serratia marcescens, 0.20 for Proteus mirabilis, 1.56 for Proteus vulgaris, 3.13 for Citrobacter spp. and >100 for Pseudomonas aeruginosa. Its activity against Gram-negative rods except P. aeruginosa was much more potent than those of cephalexin and cefaclor, but a little less so than those of cefixime and cefteram. 2) Clinical efficacy Four patients with pneumonia, 3 with bronchitis, 3 with tonsillitis, 3 with pharyngitis, 1 with gingival abscess, and 1 with cystitis were treated with CEMT-PI at a daily dose of 0.5∼1.0g for 3∼26 days. Clinical response was excellent in 4, good in 6, fair in 1, poor in 2 and unknown in 2 patients. The clinical efficacy rate was 76.9%. Five out of 9 cases which causative strains were isolated were eradicated by CEMT-PI. Heartburn, epigastralgia and abdominal fullness were observed in 3 patients. Eosinophilia was observed in 2 patients and elevated GOT, GPT, AL-P and γ-GTP in one patient.