N-acetylcysteine is the established treatment for
acetaminophen toxicity. This medication's complex dosing schedule engenders a high incidence of
medication errors. While nuisance side effects are common, only rare case reports describe serious outcomes associated with
N-acetylcysteine administration, all of which take place in the setting of non-intentional
N-acetylcysteine overdose. This case report contributes to a small but growing literature that suggests that large
N-acetylcysteine overdose may have devastating outcomes. We describe a 15-year-old female who presented with stage III
acetaminophen toxicity and who received a non-intentional 6-fold overdose of intravenous
N-acetylcysteine due to a medication prescribing error. During the
N-acetylcysteine infusion dosing error, the patient had
clinical deterioration including seizure followed by
cerebral edema and brain herniation that progressed to
brain death. She developed agitation and worsening
headache within 2 h of the dosing error, which progressed to seizure and intubation 14 h into the dosing error. Although possibly due to
hepatic encephalopathy, at the time she developed fixed dilated pupils, her
lactate, international normalized ratio,
aspartate aminotransferase, and
alanine aminotransferase had all improved. On review of the literature, other case reports of
seizures (n = 4) and
cerebral edema with brain herniation (n = 3) were found, suggesting our patient was not an isolated case. Clinicians need to be aware of the common occurrence of dosing errors for
N-acetylcysteine infusions. We suggest institutions review their
N-acetylcysteine ordering, dosing, and mixing protocols in order to avoid similar rare errors in the future. Iatrogenic overdose of
N-acetylcysteine can cause seizure,
cerebral edema, and
brain death.