Postmortem Toxicology Positivity for Medications for Opioid Use Disorder in Illinois Unintentional Opioid Overdose...

Currently, most unintentional opioid overdose deaths (OODs) in the United States are attributed to fentanyl. Buprenorphine and methadone reduce mortality associated with opioid use disorder. Despite the protective effects of these medications for opioid use disorder (MOUD), adverse outcomes are possible. The aim of this study is to describe the detection of MOUD in unintentional fentanyl-attributed OODs in Illinois.

We conducted a retrospective cross-sectional analysis of unintentional overdose deaths using the Illinois Statewide Unintentional Drug Overdose Reporting System data from 2019 to 2024. Descriptive statistics summarized demographics and MOUD detection in fentanyl-attributed unintentional OODs. Modified Poisson regression with robust SEs was used to estimate adjusted prevalence ratios (aPRs) for fentanyl-attributed unintentional OODs, adjusting for demographics, coingestants, education, housing instability, recent jail release, recent health care utilization, and calendar year.

Among 17,757 unintentional OODs, 74% (13,135) were attributed to fentanyl by a coroner or medical examiner. Median age was 44.5 years; 75% were males, and 45% were white non-Hispanic. Detection of each MOUD in fentanyl attributed unintentional OODs was consistently low over time. After adjustment, methadone detection was associated with a lower risk of fentanyl-attributed unintentional OOD (aRR: 0.92; 95% CI: 0.88-0.96). Buprenorphine (aRR: 1.05; 95% CI: 0.99-1.11) and naltrexone (aRR: 0.98; 95% CI: 0.86-1.11) were not significantly associated with fentanyl-attributed unintentional OODs.

MOUD detection in unintentional fentanyl-attributed OODs in Illinois was low from 2019 to 2024. Methadone was the only MOUD to have a protective association with fentanyl-attributed unintentional OODs.