Gray baby syndrome

by Dr. Ahmad Najmi, Index Medical College, Indore
Neonates, especially if premature, may develop a serious illness termed gray baby syndrome if exposed to excessive doses of chloramphenicol
This syndrome usually begins 2 to 9 days (average of 4 days) after treatment is started
Within the first 24 hours, vomiting, refusal to suck, irregular and rapid respiration, abdominal distention, periods of cyanosis, and passage of loose, green stools occur
The children all are severely ill by the end of the first day, and in the next 24 hours turn an ashen-gray color and become flaccid and hypothermic
A similar "gray syndrome" has been reported in adults who were accidentally overdosed with the drug
Death occurs in about 40% of patients within 2 days of initial symptoms.
Those who recover usually exhibit no sequelae.

Two mechanisms apparently are responsible for chloramphenicol toxicity in neonates: (1) a developmental deficiency of glucuronyl transferase, the hepatic enzyme that metabolizes chloramphenicol, in the first 3 to 4 weeks of life; and
(2) inadequate renal excretion of unconjugated drug. At the onset of the clinical syndrome, chloramphenicol concentrations in plasma usually exceed 100 mg/ml, although they may be as low as 75 mg/ml.
Children 2 weeks of age or younger should receive chloramphenicol in a daily dose no larger than 25 mg/kg of body weight; after this age, full-term infants may be given daily quantities up to 50 mg/kg.
Toxic effects have not been observed in the newborns when as much as 1 g of the antibiotic has been given every 2 hours to the mothers during labor.
Chloramphenicol is removed only minimally from the blood by either peritoneal dialysis or traditional hemodialysis.
Thus, exchange transfusion and charcoal hemoperfusion have been used to treat overdose with chloramphenicol in infants
Reference: Goodman & Gillmans Pharmacological Basis of Therapeutics 11th edition