grey baby syndrome

Last edited 03/2019 and last reviewed 06/2022

Chloramphenicol reaches toxic levels more readily and less predictably in neonates, causing cardiovascular collapse. This is referred to as the grey baby syndrome.

  • grey baby syndrome is a type of circulatory collapse that can occur in premature and newborn infants and is associated with excessively high serum levels of chloramphenicol
    • elevated levels of chloramphenicol circulating in the plasma result from two distinct pathophysiologic processes
          • a normally functioning liver will metabolize the chloramphenicol parent molecule (primarily by glucuronidation) - however an immature neonatal liver is unable to synthesize and recycle the UDP-glucuronyltransferase enzyme efficiently
          • neonatal kidneys are unable to excrete chloramphenicol and its metabolites efficiently
        • these two deficiencies result in elevated serum levels of chloramphenicol
      • chloramphenicol molecule displaces unconjugated bilirubin from albumin, leading to kernicterus and eventually death if untreated

  • characterized by an ashen-grey color ("grey baby syndrome"), abdominal distention, vomiting, flaccidity, cyanosis, circulatory collapse, and death
    • chloramphenicol parent molecule also displaces unconjugated bilirubin from albumin, giving way to kernicterus and eventually death or permanent neurological sequelae if left untreated

  • usually starts 2 to 9 days after treatment is started
    • syndrome is a result of chloramphenicol impairing myocardial contractility
    • believed to occur more often in neonates due to their diminished ability to conjugate chloramphenicol and to excrete the active form in the urine
    • also been reports in small children and adults that have had accidental overdoses of the drug


  • primarily aimed towards direct removal of the parent chloramphenicol molecule
    • use of modalities such as charcoal hemoperfusion and exchange transfusion
    • also been reports of phenobarbital being used for induction of the UDP-glucuronyltransferase enzyme
    • cardiopulmonary bypass including extracorporeal membrane oxygenation may also be considered