[Pharmacokinetic and clinical studies with imipenem/cilastatin sodium in neonates]

Pharmacokinetic and clinical evaluations of imipenem/cilastatin sodium (IPM/CS) were carried out in neonates. The following results were obtained: 1. The plasma concentrations of IPM/CS were determined upon doses of 10 mg/10 mg/kg and 20 mg/20 mg/kg administered using 30- and 60-minute drip infusion, respectively. Peak concentrations of IPM/CS were 19.0-34.7 micrograms/ml/32.6-73.4 micrograms/ml, respectively, at the end of the drip infusion. Plasma half-lives of IPM and CS were 1.4-1.6 hours and 1.7-2.1 hours, respectively. 2. Over a period of 6-8.5 hours, urinary excretions of IPM and CS totaled 19.8-42.7% and 46.9-89.3% of the dose administered, respectively. 3. Clinical responses to IPM/CS were excellent in 4 patients, good in 8 patients and unknown in 1 patient. 4. No side effect was observed except for a platelet increase in 2 patients. From the above results, it has been concluded that IPM/CS is an effective and safe drug in the treatment of neonatal infections.