Rochester, N.Y. – Doctors and police first issued a warning back in May when a street drug called M30 first surfaced in Rochester. It was making people sick.

They didn’t see any other cases during the summer, but last weekend, a dozen people who used M30 wound up in the Emergency Room and Rochester General Hospital.

Associate Chairman of Emergency Medicine Dr. Bryan Gargano treated some of the patients.

Dr. Gargano said they suffered severe seizures, some couldn’t turn their heads or open their mouths. Others also had serious heart palpitations.

Gargano said what people don’t realize is they take a gamble anytime they buy street drugs.

In this case, some of the patients thought they were buying the painkiller Percocet, but instead got a combination of drugs someone mixed into a pill. Gargano said someone is either making the compounds here, or shipping them in.

Doctors confiscated some of the pills and will analyze them in the lab.

Gargano said previous tests have found the pills contain the powerful synthetic opioid fentanyl, which can be fatal. The anti-psychotic drug Haldol was also detected, which can also be deadly when mixed with other drugs.

All of the people hospitalized are okay but it was a scary experience for all of them.