Postmortem femoral blood reference concentrations of aripiprazole, chlorprothixene, and quetiapine

Postmortem femoral blood concentrations of the antipsychotic drugs aripiprazole, chlorprothixene and its metabolite, and quetiapine were determined by LC-MS-MS in 25 cases for aripiprazole and 60 cases each for chlorprothixene and quetiapine. For cases where the cause of death was not related to the considered drugs, the following blood concentration intervals (10-90 percentiles) were observed: 0.049-0.69 mg/kg for aripiprazole, 0.006-0.24 mg/kg for chlorprothixene, and 0.006-0.37 mg/kg for quetiapine. These concentration ranges largely correspond to therapeutic plasma levels observed in vivo suggesting no or only limited postmortem redistribution for aripiprazole, chlorprothixene with metabolite, and quetiapine in these cases. One fatality caused by chlorprothixene with a blood level of 0.90 mg/kg was recorded, and in six cases chlorprothixene was judged to be contributing to death with concentrations 0.43-0.91 mg/kg. No fatalities exclusively ascribed to the two other drugs were observed, but aripiprazole was considered to be contributing to death in one case (1.9 mg/kg) and quetiapine in seven cases with concentrations 0.35-10.0 mg/kg. The presented values may serve as a reference for judgment of postmortem cases with presence of these antipsychotics.