The Connecticut Department of Public Health (DPH) is working with law enforcement to investigate reports of overdose patients who claimed to only have smoked marijuana but suffered overdose symptoms similar to opioid overdose, according to NBC Connecticut.

State health officials said in at least one of these cases, the marijuana in question has been tested positive for fentanyl.

The DPH said, “In many of these cases the patients had to be revived with naloxone. It appears at least one person has died.”

Since July, there have been nearly 30 such overdose cases, while most of them occurred in Plymouth. One sample found that the cannabis was laced with fentanyl.

DPH Commissioner Dr. Manisha Juthani said, “This is the first lab-confirmed case of marijuana with fentanyl in Connecticut and possibly the first confirmed case in the United States.”

Fentanyl is a powerful opioid used as a pain medication. It is highly potent and one of the leading causes of overdose deaths in Connecticut. The drug is 50 to 100 times more potent than morphine, according to the CDC.

Susan Logan, Lead Epidemiologist with DPH, said, “We want people to be aware of the fact that there are some illicit marijuana supplies that could contain fentanyl, and to be careful.”

Illicit drug market has become more volatile so the officials believe there could be more cases of overdoses.

The health departments said fentanyl could end up in marijuana accidentally if people sell different drugs. It may also be added intentionally to make it more enticing.

Ken Gray of the University of New Haven Criminal Justice said, “If you are chasing after a higher high, you have no idea what is being laced in there.”

Meanwhile, public health officials are warning marijuana users to be aware of the risks of fentanyl. They recommend that anyone using illicit drugs know the signs of an opioid overdose and keep naloxone handy as a precautionary measure.

The story appeared on NBC Connecticut.