Quetiapine (Seroquel) concentrations in seven postmortem cases.

Quetiapine is a new antipsychotic drug that has been available in the United States since September 1997. It belongs to a new chemical class of drugs called the dibenzothiazepine derivatives and is easily detected with a basic drug screen. The Los Angeles County Department of Coroner Toxicology Laboratory has encountered quetiapine in seven postmortem cases. Tissue distributions were determined in each of the seven cases. The analysis of quetiapine from postmortem specimens consisted of an n-butylchloride basic extraction with presumptive identification and quantitation on a gas chromatograph-nitrogen-phosphorus detector. Linearity was achieved from 0.10 to 3.0 mg/L with a limit of quantitation of 0.10 mg/L. Confirmation of quetiapine was performed on a gas chromatograph-mass spectrometer by comparison with a pure analytical standard. The tissue distribution of quetiapine was as follows: heart blood present, but less than (+<) 0.10-49 mg/L (seven cases); femoral blood +< 0.10-1.4 mg/L (five cases); liver +< 0.10-112 mg/kg (five cases); spleen 4.0 mg/kg (one case); urine 0-3.0 mg/L (two cases); bile 0.60-7.5 mg/L (three cases); and gastric contents +< 0.01-18 mg total (five cases). To our knowledge, this is the first report of the presence of quetiapine in postmortem specimens.