Abstract
Acute caffeine intoxication has become a rare but life-threatening clinical and forensic concern, particularly with the increasing availability of highly concentrated pure caffeine preparations. This report presents a fatal case following the intentional ingestion of a high dose of powdered pure caffeine, evaluated through an integrated assessment of the clinical course, autopsy findings, histopathological examination, and postmortem toxicological analyses. A man in his late twenties presented to the emergency department with nausea, vomiting, and tachycardia. Although transient clinical improvement was achieved with supportive treatment, he developed sudden cardiac arrest approximately 4 h later and died despite advanced life support. Autopsy revealed no specific macroscopic findings nor structural cardiac pathology that could account for the cause of death. However, a postmortem femoral blood caffeine concentration of 210.6 mg/L was detected, and caffeine was identified in multiple tissue specimens. Taken together, these findings indicated that death resulted from a fatal cardiac arrhythmia secondary to acute caffeine intoxication. This case highlights that early clinical stabilization following high-dose caffeine exposure may be misleading and underscores the critical importance of a multidisciplinary and integrated evaluation of clinical findings, autopsy results, and postmortem toxicological investigations in the assessment of fatal caffeine intoxication.