Pharmacokinetics of intravenous immunoglobulin in neonates.

Intravenous immunoglobulin (IVIG) may be a therapeutic adjunct to antibiotic treatment of neonatal infections. We examined the pharmacokinetics and safety of IVIG in human neonates. Thirty neonates with suspected sepsis were randomly assigned either to a treatment (receiving either 250, 500, or 1,000 mg/kg of IVIG plus antibiotics) or control (antibiotics alone) group. The 500 mg/kg dose produced a rise in total IgG for greater than 8 and in group B streptococcus (GBS) type-specific IgG for greater than 4-14 days. The type-specific antibody elevation varied with the amount of pathogen-specific antibody and dose of IVIG. Pharmacokinetic analysis suggests a Vdss of 42 ml/kg, Cl of 3.0 ml/kg/day, a biphasic elimination curve, and a terminal elimination half-life of 24.2 days. No toxicity was observed. These data may be valuable in determining optimal dosing schedules for IVIG in treating or preventing neonatal infections.