Fatal Opioid-Like Toxidrome Associated With a 7-Hydroxymitragynine Kratom Product

Kratom (Mitragyna speciosa) use has increased in the United States, with the market shifting from traditional leaf preparations to concentrated products containing concentrated or chemically processed alkaloids such as 7-hydroxymitragynine (7-HMG) and mitragynine pseudoindoxyl. These formulations may deliver supraphysiologic opioid-receptor agonist doses with poorly characterized toxicity. A 42-year-old man was found dead at home after reportedly ingesting 3 tablets of a commercial "7-HMG" product and several beers. Postmortem examination revealed purge fluid at the mouth and nose, severe bilateral pulmonary edema, distended bladder, and no evidence of trauma or injection drug use. Quantitative analysis of the remaining tablet showed 29 mg 7-HMG and 0.58 mg mitragynine pseudoindoxyl, with minimal mitragynine. Postmortem blood contained 37.3 ng/mL 7-HMG and 76 ng/mL mitragynine pseudoindoxyl, whereas gabapentin and other medications were present at subtherapeutic concentrations. Compared with an estimated 1 to 4.5 mg 7-HMG in a typical high dose of dried kratom leaf powder, this ingestion delivered approximately 87 mg 7-HMG (19-fold to 87-fold greater 7-HMG exposure than a high-dose botanical leaf preparation). Given the high μ-opioid receptor activity of 7-HMG and its in vivo conversion to the even more potent opioid agonist mitragynine pseudoindoxyl, the postmortem findings are most consistent with a fatal opioid-like toxidrome associated with exposure to concentrated kratom alkaloids. This case illustrates the emerging risk posed by new kratom-branded products containing purified or chemically enriched alkaloids at doses far exceeding traditional preparations.