A premature neonate given prophylactic chloramphenicol develops vomiting, hypothermia, grayish skin coloration, cardiovascular collapse and death within 48 hours. The underlying cause of this gray baby syndrome is:

• A Idiosyncratic bone marrow suppression
• B Displacement of bilirubin from albumin causing kernicterus
• C Immature hepatic glucuronidation leading to drug accumulation ✓
• D Hemolysis due to G6PD deficiency

Explanation

Neonates, especially preterm infants, have deficient UDP-glucuronyl transferase activity and reduced renal excretion, so unconjugated chloramphenicol accumulates to toxic levels and blocks mitochondrial respiration in myocardium, producing circulatory collapse. Bilirubin displacement is the reason ceftriaxone is avoided in neonates. Idiosyncratic aplastic anemia is a separate, dose-independent chloramphenicol toxicity seen later, not this acute neonatal syndrome.

Reference: Katzung Basic and Clinical Pharmacology, 15th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.