[Pharmacokinetic, bacteriological and clinical evaluation of biapenem (L-627) in the pediatric field].

Pharmacokinetic, bacteriological and clinical studies on biapenem (L-627), a newly developed carbapenem antibiotic, were performed in the field of pediatrics. 1. Antibacterial activities of biapenem against 54 strains of Streptococcus pneumoniae isolated in 1993 were compared with those of 13 other antibiotics, consisting primarily of beta-lactam compounds. Minimal inhibitory concentrations (MICs) of biapenem were < or = 0.78 micrograms/ml against all strains, and excellent values were obtained even against benzylpenicillin (PCG)-resistant strains. Based on MIC80 values, biapenem, imipenem, and cefuzonam showed highest antibacterial activities, followed by cefotaxime. 2. Blood concentrations and urinary excretion were studied after intravenous drip infusion of 6.0 mg/kg and 6.1 mg/kg of biapenem, given over 30 min., to two children (ages: 4 years and 11 years). Blood drug concentrations were 14.7 and 37.6 micrograms/ml, respectively (mean: 26.2 micrograms/ml), at 30 min. after starting infusion (at completion of infusion). Blood concentrations then declined gradually with half-lives of 0.66 and 1.16 hrs., respectively (mean: 0.91 hrs.). After 5.5 hrs., blood concentrations were no longer measurable in the former and 0.46 micrograms/ml in the latter. Urinary recovery rates of drug in the first 6 hrs. after starting administration were 65.8% and 60.9%, respectively (mean 63.4%). 3. Penetration of the drug to the cerebrospinal fluid (CSF) was studied in 2 patients with purulent meningitis. Biapenem, 31.6 mg/kg, was administered four times daily by 30-min. intravenous drip infusion. CSF concentration 1 hr. after administration was 8.54 micrograms/ml on the day of the start of treatment (day 0), and 3.00, 2.04, 16.1, 4.16, 3.24, and 1.60 micrograms/ml on days 1-7 of treatment, respectively. In a patient similarly administered with the drug at 33.7 mg/kg four times daily, the CSF concentration at 1.5 hrs. after administration was 2.62 micrograms/ml on the next day of the start of treatment. On days 2-7 of treatment, CSF concentrations at 0.5-1 hr. after administration were 4.60, 12.9, 20.6, and 1.32 micrograms/ml, respectively. 4. Clinical efficacy was evaluated in 27 patients with pediatric infections. The dose administered per dosage was 5.2-33.7 mg/kg. Three or four dosages were given daily. The duration of therapy ranged from 3 1/3 to 11 days. Total administered doses were between 0.675 and 20.475 g. Clinical efficacy was evaluated in a total of 24 patients (purulent meningitis 1, acute otitis media 1, acute bronchitis 2, acute pneumonia 19, acute urinary tract infection 1). Responses to treatment were excellent in 14 patients and good in 10 patients.(ABSTRACT TRUNCATED AT 400 WORDS)