[Pharmacokinetic and clinical studies of S-1108 in the pediatric field]

Pharmacokinetic and clinical studies on S-1108, a new oral cephem antibiotic, were performed in the field pediatrics. The following results were obtained. 1) Antibacterial activities Antibacterial activities of S-1006, the active form of S-1108, were studied against clinically isolated strains of (Staphylococcus aureus (n = 5), Streptococcus pneumoniae (n = 6), Streptococcus pyogenes (n = 3), Haemophilus influenzae (n = 8), Branhamella catarrhalis (n = 5) and Haemophilus parainfluenzae (n = 2). MIC values ranged < or = 0.025-1.56 for GPC and < or = 0.025-0.78 microgram/ml for GNR. 2) Absorption and excretion Blood concentrations and urinary excretion rates of S-1108 were measured upon administration of S-1108 after meal at dose of 3 mg/kg (n = 4), 4 mg/kg (n = 1) and 6 mg/kg (n = 1). The peak blood concentrations of S-1006 at a dose of 3 mg/kg (n = 4), ranged from 0.57 to 1.82 micrograms/ml at 1, 2 and 4 hours after dosing. Mean pharmacokinetic parameters T1/2 and AUC were 1.29 +/- 0.69 hours and 4.47 +/- 2.25 micrograms.hr/ml, respectively. At a dose of 4 mg/kg and 6 mg/kg, peak concentrations were 1.79 and 1.27 micrograms/ml at 2 and 3 hours after treatment. T1/2 and AUC were 1.34 and 1.11 hours, and 8.19 and 5.65 micrograms.hr/ml, respectively. Urinary recovery rates ranged from 13.0 to 37.2% for the first 8 hours after administration. 3) Clinical studies Clinical efficacies were examined in 32 cases of various pediatric infections including 5 cases of acute pneumonia, 11 cases of bronchitis, 2 cases of scarlet fever, 8 cases of tonsillitis, 1 case of pharyngitis, 2 cases of otitis media and 3 cases of UTI. Clinical efficacy rate was 96.9% (31/32) and bacteriological eradication rate was 87.1% (27/31). There were no side effects and abnormal laboratory test values except 1 case (Eosino. 2-->10%) in the 32 cases.