Cheese is a heroin-based recreational drug that came to the attention of the media after a string of deaths among adolescents in Dallas beginning in 2005. It is made by combining heroin with crushed tablets of over-the-counter cold medication containing acetaminophen, the active ingredient in Tylenol, and the antihistamine diphenhydramine, the active ingredient in Benadryl.
Cheese samples obtained in north Dallas contained between 2% and 8% heroin, in contrast to the 30% commonly found in black tar heroin. Users commonly take the powder by insufflation (‘snorting’) rather than by intravenous injection. This mixture is also known as ‘Tylenol With Smack,’ by analogy to the Tylenol With Codeine series. When it appeared in several public middle schools police dubbed the mixture ‘starter heroin.’
The Daily Omnivore 