Two Single-Drug Fatal Intoxications by Mitragynine

Mitragyna speciosa, a species of plant that is native to Thailand, Malaysia and Southeast Asia, contains two major psychoactive alkaloids: mitragynine and 7-hydroxymitragynine. Pharmacologically, the alkaloids exhibit biphasic effects-at low doses, stimulant effects are realized, while high doses exhibit sedative effects. For years, the plant has been used recreationally and medicinally for these effects, but its use has been implicated in and associated with intoxications and deaths. In this case report, we describe two cases whereby decedents presented with single-substance fatal intoxications by mitragynine in the absence of other postmortem toxicological findings. The cases entail young male decedents in outdoor settings (e.g., driving a vehicle and bicycle). Postmortem blood concentrations were 2,325 and 3,809 ng/mL. The medical examiner certified the cause of death as acute mitragynine intoxication in both cases. The toxicology results presented become useful when considering mitragynine to be the offending agent in lethal single-drug intoxications; further, the information included is pertinent to medical examiners, forensic pathologists, forensic toxicologists and emergency department personnel in evaluating possible poisoning and lethality by mitragynine.