In 10 states, more than 1,200 people died in one year from overdoses connected with an opioid that had been used to sedate large animals.
In a July 2018 Morbidity and Mortality Weekly Report, researchers from the Centers for Disease Control and Prevention wrote that carfentanil was connected with 11 percent of the 11,000 opioid-related deaths reported from July 2016 through June 2017 in Kentucky, Maine, Massachusetts, New Hampshire, New Mexico, Ohio, Oklahoma, Rhode Island, West Virginia, and Wisconsin. Carfentanil is the most powerful fentanyl analog, and it had been used to anesthetize wild animals from deer to elephants.
The FDA-approved version of carfentanil, Wildnil, has not been marketed for several years. The sponsor, Wildlife Laboratories, voluntarily relinquished the approval in March. Currently, no FDA-approved carfentanil formulations are available.
The 10 states included in the report were participating in a CDC opioid reporting system at the time, and another 32 states plus the District of Columbia began participating in August 2017 or planned to participate starting in August 2018.
The MMWR article published in July indicates other states have had at least hundreds of carfentanil-related deaths. The Florida Medical Examiners Commission, for example, published a separate report that Florida had 500 carfentanil-related deaths in 2016.
Provisional data also published by the CDC indicate that, throughout the U.S., about 48,000 people died of opioid-related overdoses from July 2016 through June 2017, more than four times the total reported from the 10 states. While those data show that more than half of those deaths were connected with fentanyl and other synthetic opioids, they do not show how many were related to carfentanil.
The MMWR authors noted that their agency has warned that fentanyl and related substances are becoming easier to find, pressed into counterfeit pills sold across the U.S.
"Growing outbreaks associated with fentanyl analogs are occurring at a time when sharp increases in fentanyl overdose deaths are already straining the capacity of medical examiner and coroner offices and public health departments," the article states.
Correction: This article has been updated to include information about the current status of FDA-approved carfentanil formulations.