[Laboratory and clinical studies on cefoxitin in pediatric field (author's transl)]

Studies on antimicrobial activity, absorption and excretion and clinical use of cefoxitin in pediatric field were performed. 1. MIC of cefoxitin was compared with that of cefazolin and/or ampicillin for clinical isolates of Staphylococcus aureus (36 strains), Escherichia coli (35 strains), Klebsiella pneumoniae (34 strains) and Haemophilus influenzae (80 strains). MIC of cefoxitin against S. aureus was approximately 1-2 tubes higher than that of cefazolin. Many strains of E. coli and K. pneumoniae that showed high MIC to cefazolin were sensitive to cefoxitin. It is presumed that the results are due to the strong resistance of cefoxitin to beta-lactamase degradation. MIC of cefoxitin against H. influenzae was approximately 1-2 tubes lower than that of cefazolin, but approximately 4 tubes higher than that of ampicillin. 2. Serum level and urinary recovery rate of cefoxitin after one shot i.v. injection of 25 mg/kg were examined. The serum mean levels were 33.8 microgram/ml at 1/2 hour, 7.0 microgram/ml at 1 hour and 2.9 microgram/ml at 2 hours after the injection, respectively, and the drug was not detected in serum at 4 and 6 hours after the injection. The mean half-life of serum level was 27.1 minutes. The mean urinary recovery rate within 6 hours after injection was 96.0% and most of the drug were excreted into urine within 2 hours after the injection. 3. In order to evaluate clinical response, bacteriological response and side effects, cefoxitin was applied to 19 cases, i.e., 12 cases of either acute lobar pneumonia or acute bronchopneumonia, 2 cases of acute pyelitis, 1 case each of acute bronchitis, acute purulent tonsillitis, acute purulent arthritis, acute orbital phlegmon and acute buccal abscess. As for clinical response, the overall efficacy rate (the percentage of cases showed excellent and good efficacy) was 88.9%. As for bacteriological response, among the 13 strains which were determined or supposed to be causative organisms, i.e., 6 strains of Streptococcus pneumoniae, 2 strains of H. influenzae and 1 strain each of streptococcus pyogenes, alpha-Streptococcus, Enterococcus, E. coli and Neisseria sp., all strains were disappeared except for Enterococcus which was reduced by the treatment with cefoxitin. No side effect was observed in any case. Abnormalities of laboratory findings were observed in 3 cases, i.e., 1 case each of reduction of RBC and Hb, elevation of GOT and GPT and elevation of GPT, but all of them returned to normal following completion of the dosage term.