Elephant Tranquilizer Found As Riverside County Man's Cause Of Death, Public Health Officers Say

RIVERSIDE COUNTY, CA — A Riverside County man has died as a result of a carfentanil overdose – a synthetic opioid used in the treatment of large animals that Riverside University Health System – Public Health (RUHS-PH) officials say is 100 times stronger than fentanyl and 10,000 times more potent than morphine.

The death – a male in his 40s whose name was not released – occurred in March 2025, and the incident happened outside of the county. After months of waiting for the confirmed cause of death, Riverside County Public Health Officer Dr. Jennifer Chevinsky discussed the incident in a recent news release.

"Every life lost from opioids is one too many. Together, we can continue to raise awareness about the risks associated with drug use and work as a community to support safety, reduce harm and care for one another," she said.

Carfentanil was developed for use as a tranquilizer in large animals, such as elephants, and due to its potency, even a minuscule amount can cause a fatal overdose, Dr. Chevinsky added.

According to a Centers for Disease Control and Prevention (CDC) report, illegally manufactured fentanyls (IMFs) first entered the illegal drug supply in the United States in 2013 as a substitute for white powder heroin in the Northeast.

Although rare, U.S. deaths with carfentanil detected increased approximately sevenfold, from 2 deaths in the first six months of 2023 to 14 deaths in the same period in 2024. IMFs were responsible for roughly 70% of overdose deaths in the United States in 2023, the report said.

Despite the rise in IMFs, there has been success nationally and locally, with opioid overdose deaths declining. Riverside County experienced a 25% decrease in overdose deaths in 2024. The use of naloxone (Narcan), the life-saving antidote that can sometimes revive individuals who have overdosed, and an increase in public awareness and action are among the contributing factors for the decrease.

"While overall we are seeing a decrease in opioid overdose deaths in Riverside County, this is a reminder that there are things each of us can do to prevent these terrible outcomes. Everyone deserves dignity, compassion and the opportunity to be safe," Dr. Chevinsky said.

RUHS-PH suggests residents:

• Carry naloxone. It is available over-the-counter in many pharmacies and at local public health offices. Free training and kits are available through the department.
• Share resources. Never Use Alone, the U.S. National Overdose Response line (800.484.3731), is a helpline available to individuals who are using substances by themselves. Volunteer operators take down location information and alert EMS to that location if there is no response after using.
• Offer help. Individuals struggling with substance use may call 800.662.HELP for help quitting.

Because of the unpredictability and potency, using small amounts and spacing out doses does not guarantee safety. Fentanyl strips can provide some information on a drug's contamination and risk but may not detect carfentanil.

Public Health collaborates with harm reduction organizations, local emergency responders and community partners to increase access to life-saving tools and education. RUHS-PH hosts California's first Overdose Fatality Review and participates in the Riverside County Fentanyl Multidisciplinary Committee.

RUHS-PH offers overdose prevention and harm reduction resources and hosts a data dashboard to track and inform response to overdose trends through its Riverside Overdose Data to Action (RODA) program www.ruhealth.org. For information that helped inform this program, see their data collection and analysis of County overdose data for prevention activities: www.ruhealth.org/public-health/riverside-overdose-data-action.

Narcan kits and training are available to all Riverside County residents here: www.ruhealth.org/public-health/road/naloxone-saves-lives.