Fatal atomoxetine overdose in Japan: a forensic autopsy case report

Atomoxetine has been widely used worldwide for treating attention-deficit/hyperactivity disorder. In Japan, it has been prescribed since 2009 for children and since 2012 for adults. However, no forensic autopsy cases have been reported wherein atomoxetine was identified as the primary cause of death from acute intoxication. This report describes a case of fatal acute atomoxetine intoxication in a woman in her late 20s. Prior to her death, the patient had taken several prescribed medications including atomoxetine. Cardiac blood screening, performed using a semi-quantitative analysis, detected 7-aminoflunitrazepam, 7-aminonitrazepam, allylisopropylacetylurea, aripiprazole, atomoxetine, bromazepam, and suvorexant. Among these substances, the blood concentrations of atomoxetine and bromazepam exceeded their respective therapeutic ranges previously reported in the literature. A validated quantitative analysis of two compounds was performed using ultra-high-performance liquid chromatography-tandem mass spectrometry. The atomoxetine and bromazepam concentrations were 23.2 and 0.71 µg/mL in femoral blood and 24.0 and 0.78 µg/mL in cardiac blood. In conclusion, the cause of death was primarily due to acute atomoxetine intoxication, with bromazepam excluded as a direct contributing factor.