| Abstract: | Imipenem/cilastatin sodium (MK-0787/MK-0791) was administered to pediatric patients with infections, and the following results were obtained. Pharmacokinetic study Two children, 11 years of age (38 kg body weight) and 3 years of age (15.5 kg body weight), were administered by 30 minutes intravenous drip infusion a single dose of 500 mg/500 mg (13.2 mg/13.2 mg per kg) and 250 mg/250 mg (16.1 mg/16.1 mg per kg) of MK-0787/MK-0791, respectively. Serum concentrations of MK-0787 reached their peaks at the end of drip infusion at a value of 56.33 micrograms/ml and 55.98 micrograms/ml, respectively. Concentrations of the drug decreased as the time after the administration increased, and they reached 0.14 microgram/ml and 0.12 microgram/ml, respectively in the older and the younger children at 6 hours after the administration. Half-lives (T 1/2) of the drug in serum were calculated to be 1.21 hours and 1.04 hours, respectively. The concentration of the drug in cerebrospinal fluid for the 11 years old was 0.52 microgram/ml 2 hours after the drip infusion and the serum concentration at the time was 4.02 micrograms/ml. Peak serum concentrations of MK-0791 in the 2 children were 53.73 micrograms/ml and 22.99 micrograms/ml, respectively, at the end of drip infusion. After 1 hour, the serum concentration of the drug decreased to 10.54 micrograms/ml in 1 case and not detectable in the other case. Urinary recovery rates of MK-0787 in 6 hours after the drip infusion was 82.9% and 63.6% in the 2 children and those of MK-0791 were 57.9% and 74.6%. Clinical study Clinical studies on MK-0787/MK-0791 were carried out in 6 pediatric patients; 1 each with femoral cellulitis, sepsis suspected, salmonellosis, acute tonsillitis, bronchopneumonia and streptococcosis. Lengths of treatment were 2 2/3-4 days for 5 cases and 6 days for 1 case. The patients were treated by 30-60 minutes intravenous drip infusions twice a day for 1 case, and 3 times a day for 5 cases at daily doses of 54.5-66.7 mg/kg. The treatment was effective in all cases, with 3 cases judged excellent and 3 cases good. The safety of the drug was studied in 7 patients. No side effects nor clinically abnormal values were observed in any cases. |
