Understanding Quetiapine's Involvement in Fatal and Nonfatal Drug Overdoses, Tennessee 2019-2022

Quetiapine is not currently listed as a controlled substance or scheduled in the United States; however, evidence suggests potential for misuse. As quetiapine has been found on toxicology reports during the abstraction of cases in the Tennessee State Unintentional Drug Overdose Reporting System (SUDORS), the purpose of this study was to evaluate quetiapine's involvement in both fatal and nonfatal drug overdoses in Tennessee (TN). To identify quetiapine-involved nonfatal and fatal overdoses, the TN Electronic Surveillance System for the Early Notification of Community-based Epidemics, SUDORS, and death certificates were queried using text search terms associated with quetiapine. Intentional and unintentional overdoses were included. SUDORS data were deterministically linked to controlled substances monitoring database data (CSMD) to assess prescription history in fatal overdose decedents. Descriptive statistics were calculated for the characteristics and circumstances surrounding quetiapine-involved overdoses. Chi-square tests of association and Fisher's exact tests were conducted where appropriate. There were 622 nonfatal overdoses with suspected quetiapine involvement: 397 unintentional and 225 intentional. White race Tennesseans (65%) aged 55 years or older (24.4%) or younger than 25 years old (24.1%) represented the largest proportion of nonfatal overdoses. Additionally, 144 unintentional fatal drug overdoses involving quetiapine were identified, with the largest proportion being White race (89.6%), females (63.2%), and between the ages of 35 and 54 (63.9%). We also found that 71.7% of these decedents had a history of substance use disorder. Differences were found between quetiapine-involved intentional and unintentional nonfatal overdoses and nonfatal and fatal overdoses. Given that quetiapine has increasingly appeared in fatal and nonfatal overdoses in TN and elsewhere, further research into its abuse potential may be warranted. More comprehensive monitoring of quetiapine's prescribing could help to inform prevention providers of the primary source of this emerging substance of concern.