Fundamental and clinical evaluation of cefozopran in low birth weight infants and neonates

We conducted fundamental and clinical evaluations of a cephem antibiotic, cefozopran (SCE-2787, CZOP), in infants with low birth weights and mature infants. (1) Blood concentrations CZOP was intravenously given in bolus dose of 20 mg/kg to the newborn. The blood antibiotic concentrations were 69.7 micrograms/ml at 30 minutes after administration and the elimination half life was 2.99 hours in mature infants aged 1 to 3 days. They were 38.7 micrograms/ml and 2.85 hours in those aged 4 to 7 days, and 40.8 micrograms/ml and 3.81 hours in those aged 8 days or elder, respectively. In infants with lower birth weights aged 4 to 7 days the blood antibiotic concentrations were 48.6 micrograms/ml at 30 minutes after i.v. administration and the elimination half life was 3.77 hours. The blood antibiotic concentrations at 30 minutes after intravenous doses of 10, 20 and 50 mg/kg in mature infants aged 8 days or elder were 21.1, 40.8 and 153.6 micrograms/ml (value at 60 minutes) and the elimination half lives were 2.24, 3.81 and 3.07 hours, respectively. Administration of CZOP at doses of 20 and 40 mg/kg by intravenous drip infusion over 30 minutes gave the blood drug concentrations of 48.0 and 103.2 micrograms/ml at the end of the infusion and the half lives were 2.60 and 3.33 hours, respectively. (2) Urinary excretion The urinary excretion rates after i.v. bolus doses of 10, 20 and 40 mg/kg were 28.4 to 58.6% of dose. The urinary excretion rate after i.v. drip infusion of 40 mg/kg over 30 minutes was 49.0% of dose. (3) Transfer into cereblospinal fluid The transfer of the antibiotic into cereblospinal fluid in patients with serous meningitis was 4.1 to 15.5 micrograms/ml at 1 hours after administration. (4) Clinical results The clinical efficacy was judged "good" or "excellent" in 2 of the 3 patients with septicemia and in all of the 10 patients with suspected septicemia. It was judged "excellent" in all of the 9 patients with pneumonia, 3 with urinary tract infections and 3 with intrauterine infections. Prophylactic use of the antibiotic was effective in all of the 12 patients. Of the patients in whom bacteriological evaluation was successful, 7 of the 10 causative organisms were confirmed to be eradicated. No adverse drug reactions of signs and symptoms were recognized. Fourteen abnormal alterations of the laboratory test values such as elevation of gamma-GTP and that of GPT were recognized in 8 patients (16.7%). None of them were particularly serious. These results indicate that CZOP is a drug useful for treatment and prevention of infections in infants with lower birth weights as well as in mature infants.