Large paracetamol overdose at term gestation with delayed treatment using N-acetylcysteine: A Case Report
D Gopinath, V Sabassani, M Kamran
Keywords
acetaminophen, n-acetylcysteine, overdose, paracetamol
Citation
D Gopinath, V Sabassani, M Kamran. Large paracetamol overdose at term gestation with delayed treatment using N-acetylcysteine: A Case Report. The Internet Journal of Gynecology and Obstetrics. 2008 Volume 10 Number 2.
Abstract
Paracetamol is one of the commonest drugs available in open market, liable for misuse in pregnancy. Overdose of Paracetamol results in fatal hepato-renal failure and death. Early administration of N-acetylcysteine within 10hrs has been found to reverse the hepatic damage from 89% to 3%
Case report
A 39-year-old lady was admitted at 39weeks of gestation following 64g of Paracetamol ingestion, after 48hours. On admission, her GCS was 14, vital signs were stable and cardiotocogram was reassuring. The initial blood results showed deranged liver function tests, prolonged coagulation profile and elevated salicylate and paracetamol levels. (Table1)
Labour was induced and treatment with N-Acetylcysteine was commenced immediately. Patient delivered normally in 8 hours, but sustained atonic post partum haemorrhage, controlled with oxytocics. Clotting profile normalised in 2 days and liver function tests in 7 days.
Baby had Apgars of 3 at 1 min and 8 at 5 mins. Blood results showed elevated paracetamol and salicylate levels, raised liver function tests, which required treatment with N-acetylcysteine. Baby clinically improved in 4 days. Mother and baby were discharged on day 7 and follow up at 11weeks, showed no residual liver damage.
Figure 1
Discussion
Paracetamol, one of the commonest antipyretics, causes fatal hepatorenal damage when ingested in amounts of 12g.1 It is detoxified in liver by glutathione conjugation and overdose causes binding of unconjugated toxic metabolites raising SGPT/AST levels > 1,000IU/L2 when severe.
Treatment is to give glutathione precursors like N-acetylcysteine 2 and the best predictor of hepatotoxicity was the time interval required for treatment (P<0.01)3.
Unless severe maternal toxicity develops, overdose does not increase adverse pregnancy outcome. However; treatment delays increases miscarriage and fetal death 4, 5. Fetal liver is at lower risk, as minimally metabolised by liver2 but N-acetylcysteine is transplacentally transferred in significant amounts without adverse events6.
Ludmir2, reported an overdose of 64g at 15 weeks of pregnancy, N-acetylcysteine treatment in 24 hours saving lives of both mother and baby. Our case shows that similar dose and delayed treatment after 48hrs; could have similar benefits.
Conclusion
Paracetamol overdose is not uncommon and N-acetylcysteine is an effective antidote, which should always be considered, at all stages of detection.