Ceftriaxone in infants less than 1 month has which notable side effect?

• A. Hepatotoxicity
• B. Nephrotoxicity
• C. Anemia
• D. Kernicterus and biliary sludge

Answer: (D)

In very young infants, ceftriaxone has unique safety concerns tied to bilirubin metabolism and biliary excretion. It can displace bilirubin from albumin, increasing free bilirubin levels. In neonates, whose blood-brain barrier and bilirubin-handling systems are immature, this rise in free bilirubin can cross into the brain and cause kernicterus, a serious neurologic complication. At the same time, ceftriaxone is excreted into the bile, and in neonates the biliary system is immature, so the drug can form precipitates with calcium, leading to biliary sludge or even pseudolithiasis. These Neonate-specific risks explain why kernicterus and biliary sludge are notable adverse effects in this age group.