The federal government reported a sharp increase in overdose deaths due to carfentanil, a powerful opioid 100 times stronger than fentanyl that veterinarians use on bears and elephants.
As U.S. drug users get accustomed to the ultra-potent opioid, it could result in a decrease in opioid deaths, but the opposite could also be true, according to a new report from the U.S. Centers for Disease Control and Prevention.
Carfentanil is a synthetic opioid approximately 10,000 times more potent than morphine and 100 times more potent than fentanyl.
The CDC reported a sevenfold increase in overdose deaths with carfentanil, from 29 deaths during January-June 2023 to 238 deaths during the same period in 2024. From January 2023 to June 2024, overdose deaths with carfentanil detected were reported in 37 states, according to the report.
That’s an increase of 720.7% from the first half of 2023 to the first half of 2024, according to the report.
The increase in carfentanil overdoses deaths could reverse trends that point to a decrease in overdose deaths. Provisional data project a decrease in overdose deaths in 2023 compared with the number in 2022 – the first decline since 2018.
“Recent reemergence of carfentanil … which had largely disappeared after carfentanil-involved overdose death outbreaks during 2016-2017, might threaten this progress,” according to the report.
The reemergence of carfentanil highlights the ever-evolving illicit drug market in the U.S. The report also suggests that U.S. drug users could become more able to tolerate carfentanil, potentially resulting in a decrease in overdose deaths.
“Saturation of the drug supply with [fentanyl analogues] resulting in a more stable supply might now lead to lower overdose risk as persons using drugs might have increased tolerance,” according to the CDC report. “In addition, recent mixing of non-opioid drugs (e.g., xylazine) into the fentanyl supply might reduce fentanyl purity, thereby potentially decreasing overdose risk.”
Xylazine is a non-opioid tranquilizer approved for animal use. Xylazine use can cause serious, recalcitrant skin ulcers and necrotizing wounds. Left untreated, the wounds can become infected, and in some cases, require amputation.
For years, dealers have been mixing xylazine with fentanyl and other drugs to increase potency and profits. In 2023, about 30% of all powered fentanyl contained xylazine.
In May, provisional estimates showed drug overdose deaths declined about 3.1% nationwide to 107,543. That’s down from 111,029 in 2022. Two out of every three deaths involved synthetic opioids such as fentanyl, a cheap and potent opioid smuggled into the U.S. from Mexico.
“In this context of suggested saturation of the drug supply with [fentanyl analogues] and the potential for reduced overdose risk, more persons might be able to avoid or survive overdose and subsequently benefit from overdose prevention programs that have been implemented,” according to the report. “This could be partially responsible for the decline in overdose deaths starting in late 2023.”
The report said potent synthetic could also lead to an increase in overdose deaths.
“The potential for increases in overdoses remains if drugs more potent than fentanyl, including carfentanil, continue to adulterate the supply,” the authors noted in the report.