Bilirubin-Displacing Effect of Ceftriaxone in Infants With Unconjugated Hyperbilirubinemia Born at Term

To evaluate the effect of intravenous (IV) ceftriaxone on free bilirubin concentrations in infants with unconjugated hyperbilirubinemia born at term.

A prospective study was performed with subjects serving as their own controls. Our inclusion criteria were infants born at term <7 days old with sepsis and receiving IV antibiotics for >3 days and resolving hyperbilirubinemia with total serum bilirubin levels between 6 and12 mg/dL by day 4 of life. Free bilirubin concentrations were measured by the peroxidase method using a UB analyzer and a Zone Fluidics device before (baseline) and 15 minutes after (follow-up) IV ceftriaxone administration on postnatal days 4 to 6. Paired measurements of free bilirubin were analyzed using a Student paired t-test or Wilcoxon signed-rank test.

In total, 27 infants were studied. The mean free bilirubin (μg/dL) at follow-up was not different from that at baseline when measured by the UB analyzer (P = .78). The mean free bilirubin was significantly lower at follow-up compared with baseline when measured by the Zone Fluidics device (P = .02). The ratio of a free bilirubin with and without ceftriaxone, an index of displacing effect, was 1.02 (95% CI 0.89-1.14) using the UB analyzer and 0.58 (95% CI 0.30-0.86) using the Zone Fluidics device.

Ceftriaxone is not associated with a bilirubin-displacing effect in infants with a mild unconjugated hyperbilirubinemia. Home therapy with once-daily intramuscular ceftriaxone may be an alternative option for management of sepsis in asymptomatic infants with a mild unconjugated hyperbilirubinemia born at term.