MINNEAPOLIS - Five more overdose deaths in Hennepin County have been attributed to a new opioid so powerful it is used to tranquilize elephants.

The Hennepin County Medical Examiner is blaming those deaths on carfentanil, which experts say is 10,000 times more potent than morphine and 100 times more potent than fentanyl. It is manufactured to be used as a tranquilizer for elephants and other large animals.

Victims include a 23-year-old man from Maple Grove; A 32-year-old man from Eden Prairie; A 43-year-old man from Plymouth; and a 26-year-old woman and 39-year-old man, both from Minneapolis.

Currently, routine drug and alcohol screens do not detect carfentanil , so samples must be sent to a specialized lab for testing.

The five new deaths bring the total of carfentanil deaths in Hennepin County to 10.

“We remain vigilant and continue to order the carfentanil and designer opioid testing on a case-by-case basis after considering the autopsy findings, investigation and laboratory results,” Dr. Andrew Baker, Hennepin County medical examiner, said.

Carfentanil can also harm first responders and law enforcement officers that are exposed to the drug. The substance can come in several forms, including powder, blotter paper, tablets, patches and spray. Some forms can be absorbed through the skin or accidentally inhaled. It is often disguised as heroin on the street, leaving buyers extremely vulnerable.

Naloxone can be used as an antidote for an opioid overdose of carfentanil, fentanyl, or other opioids, although multiple doses of naloxone may be required.