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A Pennsylvania district attorney is sounding the alarm about a dangerous new heroin mixture that's causing fatal overdoses.

Luzerne County D.A. Stefanie Salavantis said on Fox and Friends today that dealers - in an effort to make their heroin more powerful - are mixing in an animal tranquilizer normally used to sedate bears and elephants.

Carfentanil is said to have a potency 10,000 times higher than morphine or pure heroin and 100 times more powerful than fentanyl.

Fentanyl-laced heroin has been blamed for the increasing numbers of fatal overdoses in the United States.

Salavantis said she has not seen a carfentanil-related overdose in her county yet, but explains that it has happened in Ohio. About 20 of the overdoses were fatal, she said.

"It's making its way here," she said. 

Salavantis said another problem is that the drug is so potent, it can be harmful if it's absorbed through the skin, leading to increased risks for first responders.

She said in some cases, pure heroin is laced with the animal tranquilizer, but she's also worried about dealers simply selling carfentanil billed as pure heroin.

Salavantis said heroin addicts are typically looking for a "bigger, better high."

Salavantis said carfentanil is made in China and brought into the United States. Citing information from U.S. senators, she said it's also coming in via Mexican drug cartels. 

Watch the important interview above.

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