[Optimum dose study of cefozopran in the pediatric field]

Cefozopran (SCE-2787, CZOP) was administered to patients with pediatric infections three to four times daily by intravenous injection or 30-minute intravenous drip infusion, and investigations were made in individual cases, on relationships among doses, pharmacokinetics, effects on pathogenic bacteria and MIC against them, and clinical effects. The following results on optimal doses of CZOP were obtained. 1. Clinical cases in which CZOP was administered at a dose of 10 mg (potency)/kg The subjects were 7 patients including 4 patients with pneumonia. Severities of the diseases were severe in one of the patients with pneumonia, and moderate in the other patients. The MIC against pathogenic bacteria (4 strains) isolated from these cases ranged from 0.2 to 1.56 micrograms/ml. The serum concentrations were in a range between 1.4 and 7.6 micrograms/ml at 4 hours after administration. In some cases, the serum concentrations were lower than the MICs, though slightly. In the clinical evaluation, CZOP was excellent in 3 cases, good in 2 cases and fair in 1 case. The evaluation was impossible in 1 case. The efficacy rate was 83.3% (5/6). In bacteriological evaluation, 3 out of the 4 strains disappeared. Adverse reactions and abnormal laboratory test values were not observed. 2. Cases in which CZOP was administered at a dose of 20 mg (potency)/kg The subjects were 5 patients including 2 with pneumonia, and severities were severe in one of the patients with pneumonia, and moderate in the other patients. The MICs against the pathogenic bacteria (3 strains) isolated from these cases ranged from 0.1 to 1.56 micrograms/ml. While, serum concentrations at 4 hours after administration were in a range between 3.0 and 7.7 micrograms/ml sufficiently exceeding the MICs. In the clinical evaluation, CZOP was excellent in 1 case and good in four cases, with an efficacy rate of 100% (5/5). In the bacteriological evaluation, all the 3 strains disappeared. No adverse reactions were observed, but an abnormal laboratory test value showing eosinophilia was noted in one case. 3. Cases in which CZOP was administered at a dose of 40 mg (potency)/kg The subjects were 5 patients including 3 with pneumonia. The severity was moderate in 2 of the pneumonia patients, and severe in the other three cases. The MICs against the pathogenic bacteria (4 strains) isolated from these cases were in a range between 0.1 and 0.78 micrograms/ml. The serum concentrations at 4 hours after administration ranged from 6.5 to 21.9 micrograms/ml, sufficiently exceeding the MICs. In the clinical evaluation, CZOP was excellent in 4 cases and good in 1 case, with an efficacy rate of 100% (5/5). The efficacy rate in the bacteriological evaluation was also 100%. As adverse reaction, red urine was observed in one case. Eosinophlia was noted in one case in the laboratory tests. When CZOP was administered to patients with pediatric infections at a dose of 10 mg (potency)/kg, the clinical effect of the drug was insufficient in a case in which serum concentration of CZOP at 4 hours after administration was lower than the MICs against the pathogenic bacteria. When CZOP was administered at a dose of 20 mg (potency)/kg, sufficient concentrations were obtained, and the drug efficacies were found to be excellent or good in all cases. Therefore, the effective dose normally used is considered to be 20 mg (potency)/kg. When CZOP was administered at a dose of 40 mg (potency)/kg, the drug was found to be excellent or good in all of the cases although the severities were high in more than half of the cases tested. In addition, the rate of excellent efficacies was 80% (4/5). Furthermore, no severe adverse reactions were observed. It was, therefore, confirmed that CZOP should be administered at a dose of 40 mg (potency)/kg in severe or intractable cases.