2026 Volume 39 Issue 3 Pages 253-257
An adolescent female with a diagnosis of adjustment disorder ingested an excessive amount of diphenhydramine during a remote class conducted in a private room at school. The decedent was last confirmed alive when a teacher delivered printed materials and was found approximately 100 minutes later seated on a chair in a posture suggestive of emesis. The decedent was transported in cardiopulmonary arrest, achieved transient return of spontaneous circulation, and died one hour after hospital arrival. Autopsy revealed marked congestion and petechial hemorrhages consistent with sudden death, without evidence of aspiration. Toxicological analysis demonstrated extremely high concentrations of diphenhydramine （50.6 μg/mL in peripheral blood and 63.9 μg/mL in urine）, exceeding reported lethal levels. The estimated ingested dose was approximately twice the lethal amount. Given the short interval between ingestion and death, cardiotoxicity due to sodium channel blockade leading to fatal ventricular arrhythmia was considered the cause of death.
