SOFT 2004 Meeting Abstracts - Society of Forensic Toxicologists

P55
QUETIAPINE CONCENTRATIONS IN INTENTIONAL AND ACCIDENTAL DRUG
INGESTIONS
Martha J. Burt* and Diane M. Boland
Miami-Dade County Medical Examiner Department
Quetiapine (Seroquel) was introduced in 1993 as a neuroleptic agent in the treatment of psychosis. It has
high affinity for serotoninergic receptor sites and less affinity for dopaminergic, adrenergic and histamine
receptors. Since introduction, very few cases have been reported on the potential mortality of quetiapine
overdose, alone or in combination with other drugs. We present our case series of single drug and mixed
drug quetiapine overdoses from the Miami-Dade County Medical Examiner Department. The case records
from the years 1998 to 2003 inclusive were searched for those cases where quetiapine was detected and
quantitated in postmortem blood, gastric contents, or liver. A total of 17 cases were identified; three were
excluded because no quetiapine was detected during the quantitation process, and one was excluded
because a complete autopsy was not performed. Thus, 13 cases are reported in this series. The ages ranged
from 28 to 55 years, with a mean age of 44 years. These cases were grouped into four categories: those
where the quetiapine was the sole cause of death (Q only), those where quetiapine was related to the cause
of death (QR), those where the quetiapine was unrelated to the cause of death (QUR) and those where it
was unclear if quetiapine played any role in the cause of death (UNK). Two deaths were a result of solely
quetiapine ingestions (Q only cases). One was a 35 year old white male with central blood, gastric and
liver concentrations of 25 mgIL, 8370 mg total, and 36 mg/kg, respectively. The other was a 48 year old
white female with blood, gastric and liver concentrations of 9.5 mgIL, 954 mg total, and 34 mg/kg,
respectively. Two deaths in our series resulted from polydrug ingestions, where more than one agent,
including quetiapine could have resulted in death (QR group). The blood quetiapine concentrations were
15.6 mgIL and 13.6 mgIL, and both had significant concentrations of at least one benzodiazepine, in
addition to other agents. Four cases fell into the unknown group (UNK), where it was unclear ifquetiapine
contributed to the cause of death. In these cases, the mean quetiapine concentration was 1.86 mgIL, with a
range of 0.34 - 2.8 mgIL. All four had other drugs detected, such as benzodiazepines, alcohol and/or
cocaine. The last group, those where quetiapine clearly played no role in the cause of death, consisted of 5
cases, with a mean quetiapine concentration of 0.88 mg/L and a range of 0.27 - 1.6 mg/L. This report
provides evidence that quetiapine alone can result in death, and may significantly contribute to mortality in
poly drug ingestions. Also, this data may assist medical examiners and toxicologists in separating lethal
from non-lethal quetiapine concentrations in a variety of circumstances.
Keywords: Quetiapine, postmortem toxicology, overdose
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