A neonate treated with chloramphenicol for a resistant infection develops vomiting, hypothermia, ash-gray cyanosis, and cardiovascular collapse within days of starting therapy. The underlying mechanism of this presentation is:
- A Immature hepatic glucuronyl transferase and low glomerular filtration causing drug accumulation ✓
- B Idiosyncratic immune-mediated destruction of bone marrow stem cells
- C Oxidative hemolysis due to glucose-6-phosphate dehydrogenase deficiency
- D Displacement of bilirubin from albumin causing kernicterus
Correct answer: A. Immature hepatic glucuronyl transferase and low glomerular filtration causing drug accumulation
Explanation
Gray baby syndrome results from accumulation of unconjugated chloramphenicol because neonates have deficient hepatic UDP-glucuronyl transferase activity and reduced renal excretion, leading to shock and collapse. Option B describes the separate, idiosyncratic aplastic anemia that occurs weeks to months later and is unrelated to dose. Kernicterus from sulfonamide displacement of bilirubin is a different neonatal drug hazard.
Reference: Katzung Basic and Clinical Pharmacology, 15th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.