The course of hyperbilirubinemia in the very low birth weight infant treated with phenobarbital.

We examined the effect of early phenobarbital therapy on the course of jaundice in 57 infants with birth weight below 1,500 g. The study group of 28 infants was treated with a phenobarbital loading dose of 20 mg/kg at 4.2 (3.6) [mean (SD)] hours of age, followed by a maintenance dose of 5 mg/kg/day for one week; 29 infants served as controls. Seventeen study and 19 control infants suffered from periventricular-intraventricular hemorrhage (IVH). The two groups had comparable risk factors that can potentially affect the course of hyperbilirubinemia. Peak serum bilirubin concentration was 7.9 (1.8) mg/dl in the treated group and 8.6 (2.2) mg/dl in the control group. Three infants in the treated group and seven infants in the control group had peak serum bilirubin concentration above 10 mg/dl. These differences in the peak serum bilirubin concentration or in the number of infants with peak serum bilirubin concentrations above 10 mg/dl are not statistically significant. However, treated infants achieved peak serum bilirubin concentration earlier (mean age 90 hours as compared to 138 hours in control infants), and required phototherapy for a shorter duration of time (5.5 days in the treated group as compared to 7.5 days in the control group). While these differences in the two groups with regard to age of peak serum bilirubin concentration and duration of phototherapy are statistically significant, they do not seem to be clinically important. Thus, in our group of very low birth infants phenobarbital failed to show any clinically important effects on the course of jaundice when used in conjunction with phototherapy.