Authorities in and around the Pittsburgh say that a batch of heroin spiked with painkillers has killed at least 17 people in the area in just a week. 

The heroin has reportedly been laced with fentanyl and is being distributed in baggies labeled "Theraflu." Investigators say it's 100 times more potent than morphine.  

According to Allegheny County medical examiner Karl Williams, the number of fatal overdoses his office deals with is about 250 annually. As it currently stands, that number could balloon to 800 by the end of this year, and the Pittsburgh Post-Gazette said that at least 14 of the overdoses have occurred in Allegheny County.

In many of the cases, bags branded "Theraflu" were found at the scene. Toxicologists were working to determine how powerful the fatal doses were.

Pittsburgh mayor Bill Peduto felt compelled to deliver a cautionary statement to residents yesterday. "Those who are in possession of this potent formula are in danger of losing their lives," Peduto said. "It will kill you. The danger cannot be overstated."

[via New York Daily News and Pittsburgh Post-Gazette]