There was an approximately 8-fold increase in fentanyl concentrations, while heroin levels significantly declined, according to a recent cross-sectional study.

Researchers analyzed changes in opioid and stimulant concentrations in urine specimens from 921,931 unique samples collected between 2013 and 2023. The study aimed to quantify changes in drug exposure concentrations amid the ongoing opioid-stimulant overdose epidemic in the U.S.

The findings revealed significant increases in the concentrations of fentanyl, methamphetamine, and cocaine, with a concurrent decrease in heroin concentrations. In 2023, the adjusted fentanyl concentration was 38.23 ng/mg creatinine, an approximately 8-fold increase from 4.61 ng/mg in 2013. Methamphetamine concentrations increased from 665.27 ng/mg creatinine in 2013 to 3461.59 ng/mg in 2023. Cocaine concentrations rose from 559.71 ng/mg creatinine in 2013 to 1122.23 ng/mg in 2023. In contrast, heroin concentrations decreased from 146.59 ng/mg creatinine in 2013 to 58.36 ng/mg in 2023.

The study, published in JAMA Network Open, reports changes in the U.S. illicit drug supply, with increased exposure to fentanyl and methamphetamine, while heroin use has declined. The researchers provide data that may contribute to ongoing discussions on monitoring drug exposure trends in substance use disorder treatment.

Full disclosures can be found in the published study.