LABORATORY AND CLINICAL STUDIES OF CEFTRIAXONE IN THE PEDIATRIC FIELD

: The authors have carried out the laboratory and clinical studies of ceftriaxone (Ro 13-9904, CTRX) and obtained the following results. The antibacterial activities of CTRX against the clinical isolates of S. aureus, E. coli, K. pneumoniae, E. cloacae, E. aerogenes, S. marcescens, Citrobacter sp. and P. aeruginosa were measured by the agar dilution method with inoculum size of 10(6) cells/ml. The susceptibility distribution of S. aureus to CTRX ranged from 0.2 to 12.5 micrograms/ml, and the peak of distribution was 3.13 micrograms/ml. The peak of susceptibility distribution of E. coli and K. pneumoniae were 0.1 microgram/ml or lower, and the distribution of E. aerogenes and E. cloacae ranged from 0.1 to 100 micrograms/ml, Citrobacter sp. and S. marcescens, from 0.1 to 12.5 micrograms/ml and that of P. aeruginosa, from 0.39 to 100 micrograms/ml or more. For pharmacokinetic study, CTRX was given in a single dose of 10 mg/kg in 1 child and 20 mg/kg in 2 children by drip infusion for 1 hour. After drip infusion of CTRX in a single dose of 10 mg/kg, the peak serum level was 61.4 micrograms/ml on completion of the infusion, and 8.43 micrograms/ml at 12 hours. Half-life time was 4.6 hours. With drip infusion of CTRX in a single dose of 20 mg/kg, the peak serum level was 105.5 micrograms/ml on completion of the infusion, and 19.1 micrograms/ml at 12 hours. Half-life time was 8.7 hours. CTRX was effective all cases out of 8 cases with bacterial infection. No side effect was observed except for elevation of serum GOT in 2 cases and eosinophilia in 1 case.