[Pharmacokinetic study on oral antibiotics in pediatrics. III. A pharmacokinetic study on cefprozil in pediatrics].

The absorption and excretion were studied in the field of pediatrics, and pharmacokinetic analyses were performed. 1. Influence of food: Cefprozil (CFPZ, BMY-28100) was given to 6 school children in a before and after meal cross over design. With before meal administration, Tmax was 1.11 +/- 0.08 hours, Cmax was 5.08 +/- 0.27 micrograms/ml, T 1/2 was 0.77 +/- 0.09 hour, and urinary recovery rate (0-8 hours) was 55.2 +/- 4.7%. With after meal administration, these values were 1.31 +/- 0.04 hours, 3.98 +/- 0.38 micrograms/ml, 0.72 +/- 0.03 hour and 46.3 +/- 9.0%, respectively. A shorter Tmax value was, obtained higher Cmax and more or less higher urinary recovery rate when the drug was administered before meal, hence the food was considered to influence the absorption of the drug. 2. Dose effect: CFPZ was given on empty stomach to 6 school children in doses of 7.5 mg/kg and 15.0 mg/kg in the cross over design. With the lower dose Cmax was 6.19 +/- 0.36 micrograms/ml and AUC was 14.90 +/- 1.02 micrograms.hr/ml, and with the higher dose they were 12.38 +/- 1.29 micrograms/ml and 28.56 +/- 1.79 micrograms.hr/ml. Dose effects appeared to exist for CFPZ. A higher urinary recovery rate was obtained at the dosage of 7.5 mg/kg (82.1 +/- 6.4%) compared to the dosage of 15.0 mg/kg (51.1 +/- 7.1%). 3. Influence of age: CFPZ was given on empty stomach to 17 school children, 19 younger children and 5 infants. Tmax were 1.07 +/- 0.09, 1.06 +/- 0.07, and 1.40 +/- 0.09 hours, respectively for the 3 groups, hence significantly longer Tmax was observed in infants. Cmax were higher in older children and they were 5.62 +/- 0.38, 4.72 +/- 0.53 and 4.05 +/- 0.33 micrograms/ml, in the 3 age groups, respectively. T 1/2 were 0.73 +/- 0.04, 0.78 +/- 0.09 and 0.98 +/- 0.12 hour, respectively, it was longer in infants. The AUCs were not different among the 3 groups, but different urinary recovery rates were obtained with higher recovery in school children, with values of 64.1 +/- 4.3, 44.3 +/- 3.8 and 51.6 +/- 3.3%, respectively.