A syndrome due to toxicity of the antibiotic chloramphenicol
in the newborn, especially in the premature newborn, because of lack the
necessary liver enzymes to metabolize this drug. Usually exposed to excessive
doses of the drug (100mg/Kg). The illnes, usually begins 2-9 days after
treatment started.
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.
Signs and
symptoms
The initial symptoms in the first
24 hours are:
·
Vomiting
·
Refusal to suck
·
Irregular and rapid respiration
·
Abdominal Distension
·
Periods of cyanosis
·
Passage of loose, green stool
Son
after that they became:
·
Flaccid
·
Turn an ashen-grey colour
·
Hypothermia followed by
·
Cardiovascular collapse and death
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.
