"Cheese" is a mix of ground-up cold medicine and a small amount of heroin that has authorities in Texas concerned that drug dealers are cultivating the next generation of addicts.

USA Today reported April 26 that the mix, which DEA agents have called "starter heroin," has been seized in middle schools and high schools in Dallas, prompting the agency to issue a nationwide advisory.

"It's an emerging problem," said DEA spokesman Steve Robertson. "It's something we're tracking to see if we can spread the word before it becomes a huge problem."

The tan powder, meant for snorting, is primarily acetaminophen and diphenhydramine HCL (the active ingredients of cold medicines like Tylenol PM), mixed with up to 8 percent heroin. A hit sells for about $2, with a quarter-gram going for about $5, Dallas school officials said.

The Phoenix Academy in Dallas said six teenage patients currently in treatment had used cheese. "Kids in here, they all know lots of other kids using cheese," said program director Michelle Hemm. "This is the tip of the iceberg."