Evolution of the NBOMes: 25C- and 25B- Sold as 25I-NBOMe.

Background: The NBOMes (N-benzyl-oxy-methyl derivatives of known 2C phenylethylamines) are a new and growing class of potent synthetic stimulants. Case reports provide the bulk of available safety and clinical data for clinicians. We report two cases of NBOMe intoxication with 25C-NBOMe (the first lab-confirmed US case) and 25B-NBOMe, respectively, both confirmed via triple quadrapole mass spectrometry.

Methods: Case 1: A 16-year-old girl had a generalized seizure after reported use of 25I-NBOMe. She presented with altered mental status, lower extremity rigidity, and elevated CPK (6042 U/L). Despite treatment with benzodiazepines, her lower extremity rigidity persisted and CPK peaked at 47,906 U/L. She was discharged on hospital day 8. Serum and urine specimens confirmed presence of 25C-NBOMe. Case 2: A 15-year-old boy developed bizarre behavior after reported use of 25I-NBOMe. In the ED, he had two generalized seizures and persistent muscle rigidity. CPK peaked at 429 U/L. Seizures were managed with benzodiazepines, and he was discharged within 24 h. Serum specimens revealed 25B-NBOMe.

Conclusions: NBOMes are amphetamine derivatives and highly potent 5-HT(2A) receptor agonists. Clinical manifestations are a product of enhanced central sympathetic and serotonergic tone. We report two cases of NBOMe intoxication in patients who believed they used 25I-NBOME, while lab confirmation proved otherwise. Whether unique clinical manifestations are specific to the NBOMe variant, dose, route of administration, or other factors is unknown. Laboratory confirmation may play a role in identifying unexpected NBOMe variants, while contributing to the epidemiologic data on these novel substances.