An adolescent case of sulfhemoglobinemia associated with high-dose metoclopramide and N-acetylcysteine

Ann Emerg Med. 1999 Oct;34(4 Pt 1):538-41.


We describe the case of an adolescent girl who received high-dose metoclopramide in combination with oral N-acetylcysteine therapy for acute acetaminophen toxicity. Whole blood-sample analysis for abnormal hemoglobin pigments established the diagnosis of sulfhemoglobinemia. Metoclopramide has been shown to cause sulfhemoglobinemia, particularly when used in repeated high doses. Although N-acetylcysteine alone has not been associated as the cause, we suggest that sulfhemoglobine-mia is a potential complication in patients treated with metoclopramide for the nausea that often accompanies oral N-acetylcysteine therapy for acetaminophen toxicity. Cyanosis without respiratory distress should suggest this diagnosis.

Publication types

  • Case Reports

MeSH terms

  • Acetaminophen / toxicity
  • Acetylcysteine / therapeutic use*
  • Adolescent
  • Antiemetics / adverse effects*
  • Female
  • Humans
  • Metoclopramide / adverse effects*
  • Poisoning / drug therapy
  • Sulfhemoglobinemia / chemically induced*


  • Antiemetics
  • Acetaminophen
  • Metoclopramide
  • Acetylcysteine