| Abstract: | Pharmacokinetic and clinical studies of imipenem/cilastatin sodium (MK-0787/MK-0791), a new carbapenem antibiotic and a dehydropeptidase-I inhibitor, respectively, were carried out in a joint study in the pediatric field by a study group consisting of investigators at 16 institutions. The results were summarized below. Pharmacokinetic studies Peak plasma concentrations of MK-0787/MK-0791 were 27.7-190.0/28.3-216.4 micrograms/ml at doses of 10/10-50/50 mg/kg administered by a 30 or 60-minute drip infusion. The above findings proved that dose response was clearly observed. Over a period of 6 or 7 hours, the urinary excretion of MK-0787 and MK-0791 totaled 54.2-88.0% and 53.6-89.0% of the dose administered, respectively. Plasma half-lives of MK-0787 and MK-0791 in the beta-phase were 0.87-1.05 hours and 0.59-0.95 hour, respectively. The cerebrospinal fluid (CSF) levels of MK-0787 in patients with purulent meningitis were 2.0-14.4 micrograms/ml; however, the penetration rate of the drug into the CSF was relatively poor in patients with normal meninges. Clinical study Clinical efficacy was evaluated in 283 patients. In 112 patients the daily dosage ranged from 30/30 mg/kg to 59/59 mg/kg, and in 138 patients it ranged from 60/60 mg/kg to 99/99 mg/kg. The maximum dose administered was 222/222 mg/kg. The drug was administered either 3 or 4 times per day. The clinical efficacy rate was 92.5% among 187 patients with identified etiologic pathogens. The drug was effective in 3 out of 4 patients with purulent meningitis and in 7 out of 10 patients with septicemia. The clinical efficacy rate was 96.7% in 90 patients with respiratory tract infection (pneumonia, lung abscess, etc.), 96.5% in 57 patients with urinary tract infection, 90.9% in 11 patients with SSTI. The clinical efficacy rate in those with no identified etiologic pathogen was 97.0% among 101 patients. Bacteriologically, the eradication rate for S. aureus was 87.9% of 33 isolates. Comprehensively, the eradication rate for Gram-positive bacteria was 94.7% of 75 isolates. The eradication rate for P. aeruginosa was 87.5% of 8 isolates. Including these strains, the eradication rate for Gram-negative bacteria was 90.3% of 134 isolates. The MK-0787/MK-0791 exhibited an eradication rate of 91.9% among a total of 211 Gram-positive and Gram-negative bacteria including anaerobes.(ABSTRACT TRUNCATED AT 400 WORDS) |
