Abstract

Gray baby syndrome (also termed Gray or Grey syndrome) is a rare but serious side effect that occurs in newborn infants (especially premature babies) following the accumulation of antibiotic chloramphenicol.

Signs and symptoms

Toxic levels of chloramphenicol after 2–9 days result in:

- Loss of appetite

- Vomiting

- Ashen gray color of the skin

- Hypotension (low blood pressure)

- Cyanosis (blue discolouration of lips and skin)

- Hypothermia

- Cardiovascular collapse

- Hypotonia

- Abdominal distension

- Irregular respiration

- Increased blood lactate

Pathophysiology

Two pathophysiologic mechanisms are thought to play a role in the development of gray baby syndrome after exposure to the anti-microbial drug chloramphenicol. This condition is due to a lack of glucuronidation reactions occurring in the baby, thus leading to an accumulation of toxic chloramphenicol metabolites. :

1. The UDP-glucuronyl transferase enzyme system of infants, especially premature infants, is immature and incapable of metabolizing the excessive drug load.

2. Insufficient renal excretion of the unconjugated drug.

Due to these two reasons the chloramphenicol level in blood is increased, at higher concentration chloramphenicol blocks electron transport in the liver, myocardium, and skeletal muscles, resulting the above symptoms.

Prevention

The condition can be prevented by using chloramphenicol at the recommended doses and monitoring blood levels, or alternatively, third generation cephalosporins can be effectively substituted for the drug, without the associated toxicity.

Treatment

Chloramphenicol therapy should be stopped immediately. Exchange transfusion may be required to remove the drug. Sometimes, phenobarbital (UGT induction) is used.