Large- animal sedative implicated in human drug overdoses.

Carfentanil a drug used to sedate elephants and other large animals which is 100 times as potent as the fentanyl have been found to be mixed with or passed off as heroin. The appearance of carfentanil, one of the most potent opioids known to investigators, has added another angle to cases of drug overdoses, heroin and abuse of fentanyl. Carfentanil is so powerful that zoo veterinarians typically wear face shields, gloves and other protective gear — "just a little bit short of a hazmat suit" — when preparing the medicine to sedate animals because even one drop splattered into a person's eye or nose could be fatal, said Dr. Rob Hilsenroth, executive director of the American Association of Zoo Veterinarians