[Pharmacokinetics of panipenem in neonates and dosage recommendation]

The pharmacokinetics of panipenem/batamipron (Carbenin; PAPM/BP) was studied in 17 neonates of the postconceptional age (PCA) of 25.6 to 43.1 weeks. PAPM/BP was administered at 10 mg/kg to 20 mg/kg every 12 hours over 60 minutes by intravenous infusion. Blood samples were obtained just prior to the infusion, one or two hours and six hours after the infusion. All the data for the 85 serum PAPM concentrations were analyzed by one-compartment model using a nonlinear mixed-effect model (NONMEM). The pharmacokinetic parameters in these population are given below: CLPAPM; 0.239 +/- 0.206 (L/hr), VdPAPM; 0.97 +/- 0.80 (L), Half Life; 3.1 +/- 0.5 (hr). Half life in the patients with PCA < 34 (2.66 +/- 0.44 hr) were significantly lower (p < 0.001) than that with PCA > or = 34 (3.39 +/- 0.23 hr). Our results suggest that postnatal alterations in the PAPM excretion are related to maturational changes in the renal function and that we should consider the values of PCA when determining the initial PAPM/BP dosing regimen in neonates. We conclude that the dosage of 10 mg/kg to 20 mg/kg every 12 hours are adequate treatment for neonatal infectious disease.