Toxic boost: Acute, reversible neurotoxicity after ingestion of methylcyclopentadienyl manganese tricarbonyl (MMT) mistaken for an energy drink

Abstract Methylcyclopentadienyl manganese tricarbonyl (MMT) is an organometallic compound used as a gasoline additive for its antiknock properties. Human ingestion of MMT has not previously been reported. We present the case of a 54-year-old man who developed seizures and altered mental status after drinking 12 oz. of MMT-containing NOS Octane Booster Racing Formula. Due to label similarities, he mistook this for the NOS High Performance energy drink. The patient was intubated due to persistent seizures despite benzodiazepine treatment and admitted to the intensive care unit. He had two further seizures while intubated, but he was successfully extubated on the 4th day post-ingestion. He was confused and ataxic following extubation, but one day later his symptoms resolved and he was discharged without further incident. This case highlights the importance of responsible labeling of consumables. It is important for clinicians and poison centers to report any such instances to the United States Food and Drug Administration.