State officials say an extremely powerful synthetic opioid has been linked to a Connecticut overdose death for the first time.

They say carfentanil, which is sometimes used to sedate elephants, played a role in a Norwalk man's overdose death in April.

Connecticut State Police said Friday they recently had a case involving two other drug samples that tested positive for carfentanil.

Carfentanil, which is 100 times stronger than fentanyl and 10,000 times more powerful than morphine, was also recently detected in three drug samples for the first time in Massachusetts. Fentanyl, which is sometimes blended with heroin or other street drugs, is already blamed for a growing number of overdose deaths.

"Drug users have no idea what they're getting into, and obviously there's no one who regulates what they're getting," says Dr. Richard Greiner, of Bridgeport Hospital. "So they could be getting anything, and with carfenanil, it's way more scary."

Dr. Greiner says the emergency room at his hospital has reduced its opioid prescriptions by 40 percent because of the addictive dangers associated with the drugs.

These cases come less than a year after DEA officials said the agency wasn't aware of any lab analysis that had identified carfentanil in Connecticut or New England.

Authorities say carfentanil can be absorbed through the skin or accidentally inhaled.

The president of a local drug recovery program says people need to be very careful when dealing with a drug of this strength.

"No one in the state of Connecticut really should be dying from opioid overdose," says Alan Mathis, of Liberation Programs. "We should not be initiating the use of those substances but it you have for whatever reason there are perfectly good treatments that will help you."

Mathis says recreational drug use is dangerous and people should also consult a doctor for pain.

The Associated Press wire services helped contribute to this report.