Temporal and geographical patterns of nitazene detections in drug samples and biospecimens in the United States, 2019-2024.

Nitazene detections increased sharply across the United States between 2019 and 2024, with shifting patterns in the prevalence of individual nitazenes and extensive polysubstance involvement. These findings highlight the need to strengthen drug testing capacity, expand epidemiological surveillance and implement targeted public health interventions to mitigate harms associated with this emerging class of synthetic opioids.