Paracetamol Poisoning In Children:
Paracetamol is a commonly prescribed drug in Medical practice. It is rapidly absorbed on oral intake and metabolized to sulph and glucoronide group. Small amount is excreted in Urine.
Mechanism Of Toxiciy:
- Paracetamol is Metabolised to NABQI ( N- Acetyl –p-BenzoQuinimine) . Glutathione detoxifies it into Mercatopuric acid which is excreted in urine.
- At Toxic Level, when >70 % of Glutathione is depleted , NABQI combines with Hepatic Macromolecules causing hepatocellular damage.
- Stage I ( within 24 hours) : Anorexia, Nausea/vomiting, malaise,pallor,diaphoresis.
- Stage II ( 24-48 hours): Resolution of symptoms of stage I. Rt. Upper quadrant pain, Deranged LFT, Oliguria, tachycardia, hypotension.
- Stage III (72-96 hours) : LFT abnormal peak, coagulopathy, hepatic encephalopathy, renal failure.
- Stage IV (4 days-2 weeks ) : Resolution of hepatic dysfunction, resolution of organ failure.
Laboratory investigations :
- Serum Transaminase levels : ALT and AST raised at 24 hours, peak at 72 hours
Serum ALT/AST more than 1000IU/L- toxicity defined.
- Serum Glucose, PT and Bilirubin, hepatic enzymes.
- Electrolyte, KFT, Lactate.
- Urine analysis for proteinuria and hematuria – ATN.
Prognostic Factors :
- pH, Serum Creatinine, PT, Lactate.
- Toxic Dose – 200mg/kg in children or 7.5 gm at once in adolescents.
Differential Diagnosis :
- Reye’s syndrome
- Infective Hepatitis
- Small amount ingestion needs only observation.
- Gastric Lavage
- Activated Charcoal
- Serial measurements of LFT, PT, Creatinine
- Specific Antidote : N-acetyl cysteine(NAC), which is a precursor for glutathione synthesis.
140mg/kg Loading dose, then 70mg/kg 4 hourly for 3 days.
Methionine can also be used.
( Compiled For Use by Medical personal and Students only, Do not use drug without Prescription)
By : Dr. Merry Shrestha