N-Ethylhexedrone: A very long and bad trip! A case series.

N-ethylhexedrone (NEH) is a new cathinone derivative with, currently, low toxicokinetic and toxicodynamic knowledge. We present three documented clinical cases of NEH intoxication with plasma and urine concentrations. A thorough search for metabolites was performed. The three patients were admitted to the emergency department, and two out of the three were hospitalized for an extended period. While recovering from the drug effects, 12-24 h after nasal intake of New Psychoactive Substance (NPS), the patients described the following disorders: anxiety, feelings of persecution, asthenia, anhedonia, abulia, psychomotor slowing and loss of consciousness. NEH was identified in all samples by liquid chromatography-high resolution mass spectrometry (LC-HRMS), and quantified by liquid chromatography coupled to tandem mass spectrometry (LC-MS-MS). Quantitative analysis showed decreasing concentrations over time: for Case 1, from 97.2 (Day 1, D1) to 0.7 (Day 7, D7) µg/L for plasma, and from 724 (D1) to 0.5 (D7) µg/L for urine. NEH concentration of 7.9 µg/L was found in the plasma collected at admission for Case 2. For Case 3, concentrations ranging from 49 (D1) to 1.8 (D7) µg/L in plasma, and from 327.3 (Day 6, D6) to 116.8 (D7) µg/L in urine were found. NEH was no longer detected in the urine sample at Day 10. Elimination half-life was estimated at 19, and 28 hours in Patients 1 and 3, respectively. Four metabolites were identified in blood and urine: reduced NEH, dealkyl-NEH, reduced dealkyl-NEH and hydroxy-NEH. The cases presented highlight the long detectable lifetime of NEH. Characterization of the metabolites will allow better identification of the consumption of this drug. Serious adverse events can be observed after NEH consumption, as two out of the three patients required intubation and ventilation. A syndrome of inappropriate antidiuretic hormone secretion (SIADH) was also diagnosed. Two out of the three cases are notable because of the number of samples collected and because NEH was the only drug of abuse detected.