| Abstract: | Fundamental and clinical studies were carried out on ceftazidime ( CAZ ), a new cephalosporin, in the field of pediatrics. 1. Antimicrobial activity MICs of CAZ were determined for clinical isolates of 24 strains of S. aureus, 15 of S. pyogenes, 8 of H. influenzae, 22 of E. coli, 20 of K. pneumoniae, 18 of P. mirabilis, 3 of P. morganii, and 21 of P. aeruginosa, and compared with those of the control drugs, i.e. CEZ, CXM, CMZ, CTX, LMOX and CMX. For P. aeruginosa, CPM, CFS and GM were also employed as the control drugs. CAZ was as active as CTX, LMOX and CMX, its MICs distributing in the range not higher than 0.10 microgram/ml for H. influenzae, 0.78 microgram/ml for E. coli, 0.39 microgram/ml for K. pneumoniae, 0.10 microgram/ml for P. mirabilis, and 0.10 microgram/ml for P. morganii in all the strains. Against P. aeruginosa, CAZ showed MICs in the range between 0.39 and 3.13 micrograms /ml, which showed activity higher than that of CTX, LMOX , CPM, CMX and GM, and comparable to that of CFS. Against S. pyogenes, CAZ was as active as all the control drugs except for LMOX , its MICs for all strains tested being 0.20 microgram/ml or below. Against S. aureus, CAZ was slightly more active than LMOX , but less active than the other control drugs, its MICs being relatively high ranging from 6.25 to 50 micrograms/ml. 2. Pharmacokinetics After a one-shot intravenous injection of CAZ 20 mg/kg, serum levels and urinary excretion were studied in 3 children aged 6 to 9 years, and CSF levels were determined in 2 children aged 6 to 7 years with aseptic meningitis. The mean serum levels of CAZ were 85.3 micrograms/ml at 1/4 hour, 53.3 micrograms/ml at 1/2 hour, 32.0 micrograms/ml at 1 hour, 16.1 micrograms/ml at 2 hours, 5.3 micrograms/ml at 4 hours, and 2.0 micrograms/ml at 6 hours, with the mean half-life of 1.18 hours. The mean urinary levels were 9,700 micrograms/ml at 0 to 2 hours, 803 micrograms/ml at 2 to 4 hours, 540 micrograms at 4 to 6 hours, and the mean urinary recovery rate during the first 6 hours was 83.9%. The CSF levels at 1 hour after intravenous injection were 0.44 microgram/ml in acute stage and 0.10 to 0.22 microgram/ml in convalescent stage. 3. Clinical study Thirty-one pediatric patients with bacterial infections were treated with CAZ , and the clinical efficacy, bacteriological response, and side effects were evaluated.(ABSTRACT TRUNCATED AT 400 WORDS) |
