Early evidence of the effects of xylazine-adulterated fentanyl in Ohio.

backgroundXylazine is becoming a prevalent fentanyl adulterant in the US. It has been associated with severe wounds and withdrawal symptoms. However, its impact on fatal overdose rates is poorly understood.

methodsPoisson and ordinary least squares regression analyses are used to estimate the relationship between xylazine prevalence and unintentional overdose death and death rates at the county-month level in Ohio from April through December 2023. Xylazine prevalence is calculated from the Ohio Bureau of Criminal Investigation's (BCI) Crime Lab Data, and mortality data is from the Ohio Department of Health.

resultsXylazine prevalence is positively correlated with overdose deaths and death rates in large population counties. Xylazine adulteration is associated with 319 more overdose deaths [95 percent CI: 147-491 deaths], 10 percent of all unintentional overdose deaths in Ohio, over the nine-month period. Our estimates predict that if all fentanyl had been adulterated with xylazine over these nine months, this would have led to an additional 519 deaths. DISCUSSION: Although the data covers a limited time period, our estimates provide evidence that xylazine-adulterated fentanyl is likely to lead to additional overdose deaths as it continues to spread across the US, blunting the initial signs of a declining trend in overdose deaths. If the findings can be extrapolated to the rest of the country, it is likely that overdose deaths would have fallen more substantially in 2023 if xylazine had not already been so prevalent in large parts of the US.