Pharmacokinetics of meropenem in preterm neonates

The objective of this study was to evaluate and compare the pharmacokinetic s of meropenem in premature neonates, both after the first dose and during steady state at day 5, after a 1-minute intravenous administration to evalu ate the possibility of twice-daily administration. Seven premature neonates received 15 mg/kg meropenem twice daily on clinical grounds as a 1-minute infusion. After the first dose and during steady state at day 5, serum leve ls of meropenem were measured for 12 hours after intravenous administration . Meropenem pharmacokinetics at the first dose were studied in seven childr en (mean birth weight 925 g, mean postnatal age 21 days). Serum concentrati on-time curves could be described with a one-compartment model. Mean total body clearance was 0.157 L/kg per hour, volume of distribution was 0.74 L/k g, and half-life was 3.4 hours. At day 5 at steady state, pharmacokinetic p roperties did not differ significantly. No side effects were noted. A 1-min ute intravenous administration is feasible. Pharmacokinetic properties are comparable at day 5 compared with the first dose, and half-life is such tha t twice-daily administration of 15 mg/kg produces adequate serum concentrat ions.