Officials in the Cincinnati area (Cuyahoga County) have issued an alert about human use of the potent animal opioid sedative carfentanil, one of the strongest opioids on the market, with a potency approximately 10,000 times that of morphine and 100 times that of fentanyl. Carfentanil is an analog of the synthetic opioid analgesic fentanyl and is used as a sedative or in general anesthesia for large animals, including elephants. Side effects of fentanyl analogs in humans are similar to those of fentanyl itself, which include itching, nausea, and potentially serious respiratory depression, which can be life-threatening. Officials in Ohio have noted a high number of overdoses in a short period of time that are suspected to be from carfentanil. NIDA’s National Drug Early Warning System (NDEWS) reports several confirmed deaths in Akron and Columbus, and numerous seizures of the drug throughout Ohio. Read the public health warning from Cuyahoga County, Ohio.
In Florida (Manatee County), there was a recent seizure of carfentanil and a coincidental increase in overdoses and deaths. While more than a dozen fentanyl analogs are commonly flagged in postmortem testing in many states, it is difficult to assess how commonly carfentanil is being abused because states have few reference materials on this drug and few labs are equipped to test for it. The forensic toxicology laboratory researchers at the University of Florida are currently developing a new assay for the identification of carfentanil and will soon start including it in postmortem overdose death testing. Laboratory personnel are being warned about the potency of the drug and are advised to handle it with great care. Naloxone (Narcan®) should be available in the case of accidental exposure.
As with many fentanyl analogs, it is likely that carfentanil is being added to mixtures of heroin and other street drugs. Currently, it is unclear how often carfentanil is being added to or substituted for other opioids in street drugs, underscoring the risks of using illegal drugs.
More information can be found at the National Library of Medicine's Pubchem database – carfentanil.