Massive acetylcysteine overdose associated with cerebral edema and seizures

Context. Acetylcysteine is a safe and effective treatment for the prevention of hepatic injury due to acetaminophen poisoning. While dosing errors are common, in most cases, overdoses produce minimal clinical effects. Case report. We describe a patient who received 150 g of IV acetylcysteine over 32 h when the clinician ordered the infusion doses be administered as an hourly dose (100 mg/kg/h) rather than administered over the infusion duration (100 mg/kg over 16 h). After approximately 28 h of receiving 100 mg/kg/h, the patient developed delirium, and seizures that progressed to cerebral edema, uncal herniation, and ultimately severe brain injury. No other cause for her symptoms was identified during an extensive workup. Discussion. This case suggests that massive IV acetylcysteine overdose can cause cerebral dysfunction and life-threatening effects.