Fatal myocardial infarction associated with intravenous N-acetylcysteine error

Clinicians should be aware of potential complications when deciding on which formulation of N-acetylcysteine to administer.A 53-year-old male presented with altered mental status after an overdose of acetaminophen/hydrocodone and carisoprodol. He had an acetaminophen level of 49 mcg/ml with an unknown time of ingestion. The patient was admitted to the intensive care unit (ICU) on a naloxone drip and was started on intravenous N-acetylcysteine (NAC) at the presumed dose of 150 mg/kg. Shortly after initiating the NAC infusion, the patient developed periorbital edema, skin rash, and hypotension. The infusion of N-acetylcysteine was immediately stopped and the patient required emergent intubation. Resuscitation was begun with intravenous fluids followed by the initiation of phenylephrine. He developed ST elevation in the inferior leads on his ECG. This evolved into an inferior myocardial infarction by ECG and cardiac enzymes. Echocardiogram showed global, severe hypokinesis with an ejection fraction of less than 20% in a patient with no pre-existing cardiac history. Despite aggressive support, he died approximately 17 hours after the initiation of intravenous NAC. Further investigation found a 10-fold formulation error in his NAC loading dose.The intravenous formulation of NAC has a higher probability of significant adverse effects and complications not described with the oral formulation. Clinicians should be aware of these potential complications when deciding on which formulation to administer.Acetaminophen is one of the most commonly used over-the-counter (OTC) analgesics and one of the most common causes of poisoning worldwide. Additionally, it is used in combination with both prescription narcotics and OTC medications, making it one of the most accessible medications for potential ingestions. Annually, poison centers receive more than 93,000 calls regarding acetaminophen exposures [1]. Fortunately, antidotal therapy is available for acetaminophen toxicity in the f