[Fundamental and clinical studies on imipenem/cilastatin sodium in the pediatric field]

Fundamental and clinical studies were performed on a newly developed carbapenem antibiotic, imipenem/cilastatin sodium (MK-0787/MK-0791), and results were summarized as follows. The antibacterial activity of MK-0787 at an inoculum of 10(6) cells/ml against strains of S. aureus which were sensitive or resistant to cefazolin (CEZ), E. coli, P. mirabilis, K. pneumoniae, S. marcescens and P. aeruginosa were determined and compared with activities of ceftazidime (CAZ), CEZ, cefmetazole (CMZ), ceftizoxime (CZX), latamoxef (LMOX), cefamandole (CMD), cefoperazone (CPZ), cefsulodin (CFS) and piperacillin (PIPC). The peak MIC of MK-0787 was less than or equal to 0.024 micrograms/ml against S. aureus, which were sensitive or resistant to CEZ, 0.10 micrograms/ml against E. coli, P. mirabilis, or K. pneumoniae, 0.39 micrograms/ml against S. marcescens and 1.56 micrograms/ml against P. aeruginosa. The antibacterial activity of MK-0787 against these bacteria was, on the whole, superior to that of CAZ, CEZ, CMZ, CZX, LMOX, CMD, CPZ, CFS or PIPC. The pharmacokinetics of MK-0787/MK-0791 was studied in 10 children at dose levels of 10 mg/10 mg/kg and 20 mg/20 mg/kg by a 30-minute intravenous drip infusion. Maximum serum levels of MK-0787, at dose levels of 10 mg/10 mg/kg and 20 mg/20 mg/kg were 41.6 micrograms/ml and 72.9 micrograms/ml, respectively, at the end of infusion and 0.1 micrograms/ml at 6 hours, respectively, after drip infusion. The half-life of both dose levels was 0.9 hour. Mean peak serum levels of MK-0791, at dose levels of 10 mg/10 mg/kg and 20 mg/20 mg/kg, were 49.7 micrograms/ml and 87.0 micrograms/ml, respectively, with half-life of 1.1 and 0.6 hour, respectively. Urinary recovery rates of MK-0787 for 6 hours at dose levels of 10 mg/10 mg/kg and 20 mg/20 mg/kg, were 47.8-82.7% and 25.5-78.0%, respectively, and of MK-0791 for 6 hours were 51.7-93.4% and 40.3-94.4%, respectively. Twenty-four patients, including 1 with purulent meningitis, 1 with septicemia, 1 with pyothorax, 10 with bronchopneumonia, 7 with pyelonephritis and 4 with infections of cutaneous soft tissue were treated with MK-0787/MK-0791 at dose levels of over 100 mg/100 mg/kg/day with purulent meningitis and septicemia and 28.8 mg/28.8 mg-72.8 mg/72.8 mg/kg/day with other infections. The clinical response in all patients was excellent or good.(ABSTRACT TRUNCATED AT 400 WORDS)