A Case of Suspected Cocaine Adulterant-Associated Methemoglobinemia in the United States.

A 30-year-old male with a past history of polysubstance use presents to a drug rehabilitation facility after cocaine and heroin use just prior to arrival. While drinking at a water fountain at the facility, he became unresponsive. He was discovered to have an oxygen saturation of 50% on room air with an improvement to 87% on non-rebreather masks. Arterial blood gas revealed a methemoglobin level of 45.8%. The patient was given methylene blue with a repeat methemoglobin level of 0.00% within six hours. We attribute this presentation to local anesthetic-adulterated cocaine, a well-documented cause of methemoglobinemia in the United Kingdom rarely described in the United States.