Carfentanil, or carfentanyl, available to veterinarians under the brand name Wildnil, is an extremely potent opioid drug. It is used to control pain in large animals such as elephants and bears. It is much stronger than other opioids and can cause deadly overdoses in much smaller doses. Fentanyl can kill in a dose about the size of 6 grains of salt, and carfentanil is estimated to be 100 times stronger than fentanyl. Carfentanil is so hazardous that first responders and laboratory technicians have been warned to take careful precautions when handling substances suspected of containing this drug. They must wear gloves, masks, and other protection to cover all skin and airways. Naloxone (Narcan) and airway support must be present for workers in case of accidental exposure, due to the danger of this drug.
Due to the potency of carfentanil, it is easily smuggled into the United States in small packages, which are difficult to detect. Consequently, the drug is often mixed into other drugs, without users being aware of what they are taking. Carfentanil can be lethal when mixed into what appear to be bags of less potent drugs. Carfentanil has killed thousands of people, most of them thinking they are taking a less potent opioid like oxycodone or hydrocodone. It is a good reason to stay away from street drugs. If street opioids are taken, a sober friend should be present at all times, ready to administer naloxone and alert first responders.