Researchers found that naloxone use did not increase relative to the number of overdoses as deaths have fallen since 2023, suggesting that other factors may be driving the national decline in overdose deaths.
PROVIDENCE, R.I. [Brown University] - Increased use of the overdose-reversing drug naloxone may not be a major reason opioid overdose deaths have fallen sharply across the U.S. since 2023, according to a study that challenges a leading explanation for the decline.
"There are big questions about why opioid overdose mortality rates are falling nationally since 2023," said study co-author Dr. Michael Barnett, a researcher at the Brown University School of Public Health and a physician at Brigham and Women's Hospital. "A lot of people think that increased use of the overdose reversal agent naloxone is a big reason. This study changes the narrative and says we have to look to other causes for overdose declines."
Published as a research letter in JAMA with authors from Virginia Commonwealth University and the University of Pittsburgh, the analysis of 2.5 million nonfatal overdoses comes after decades of rising opioid overdose deaths, a trend that began reversing in May 2023. In recent decades, efforts to expand access to naloxone, commonly known by the brand name Narcan, have made the medication more widely available to people who use drugs, their families and emergency responders. States loosened barriers to access, community distribution programs expanded, and federal regulators approved Narcan for over-the-counter sales.
Despite wider availability, the researchers found no corresponding increase in naloxone use relative to the number of overdoses captured in emergency medical services data, including records from 5,324 EMS agencies nationwide between May 2020 and December 2025.
Comparing trends before and after May 2023, researchers found that nonfatal drug overdoses were 20.9% below levels projected from earlier trends, while opioid-related overdoses were 32.7% below projections. Naloxone administrations also fell, dropping 21.3% below projected levels.
Because fewer overdoses would naturally mean fewer people needing naloxone, the researchers also examined how often the medication was administered relative to the declining number of overdoses. They found that naloxone was being used at nearly the same rate as before the decline. Use by bystanders, including friends and family members, however, was 28.6% lower than expected based on earlier trends, even after accounting for the decline in overdoses.
Barnett said the findings suggest that fewer overdoses overall - possibly because of changes in the illicit drug supply or how people use opioids - may be helping drive the decline in deaths rather than more people being revived with the medication. The study did not examine those possible explanations directly, Barnett added, or look at what caused the overall decline. The data also did not capture overdoses handled outside the emergency medical system, including those reversed by bystanders without a call to 911.
The findings point to the need for further research into what's driving the decline in overdoses and how public health efforts can help sustain it, according to the authors.
