During the past year, several governmental and news agencies have reported an apparent outbreak of what they describe as a dangerous new drug called "cheese" or "cheese heroin" in Dallas schools. "Cheese heroin" is the term being used to refer to a powdered blend of acetaminophen, diphenhydramine (Benadryl), and black tar heroin. Acetaminophen and diphenhydramine is a combination found in Tylenol PM which is ground into a powder and mixed with sticky black tar heroin. In addition to cutting the potency of the heroin, this adds the effects of diphenhydramine and facilitates insufflation (snorting).

KHOU News reports that "Laboratory analysis shows 'Cheese' contains approximately 94.5%- 95% acetaminophen, 4.5%-5% diphenhydramine HCL, and 0.5%-1.0% heroin." Numerous other stories report a range of heroin concentrations, from 1-8%. In March 2007, a DEA laboratory in Dallas, Texas analyzed 15 samples of "cheese" heroin submitted by Dallas Independent School District (DISD) police. The DEA reports:

Of the 15 samples, 9 appeared to meet the classic definition of "Cheese". One sample contained only heroin, two contained 6-monoacetylmorphine instead of heroin (probably resulting from the decomposition of heroin in the original "Cheese" sample), two appeared to be "Cheese" that also contained a small amount of methamphetamine, and one had no controlled substances. The average heroin quant [sic] for these samples (calculated as the hydrochloride) was 2.0 percent.1

In news media stories, the name "cheese" is most often said to refer to the parmesan-cheese-like consistency of the powder. While its consistency may reinforce the name, a more plausible explanation for the etymology may be word play on chiva, a slang term for heroin. In 2006 "cheese" heroin was selling in Texas for $5 for 0.25 g. and $10 for 0.5 g.2

Erowid received an Experience Report describing "cheese" heroin preperation and use in 2005. One of the first major stories on "cheese" heroin appeared in the DEA's Microgram newsletter in 2006:

Between August 15, 2005, and March 1, 2006, the Dallas Independent School District Police Department handled 54 felony offenses and 24 found property cases involving a new drug mixture known on the street as "Cheese", a so-called "starter form" of heroin. "Cheese" is typically found folded inside a small paper bindle, and in the Dallas area is popular among Hispanic juveniles, both male and female, with known users as young as 13 years old.3

It is believed that recent changes in the structure of heroin production and distribution networks in Mexico resulted in a sharp increase in heroin imports into the United States from Mexico.4 Dallas Morning News reports:

Although Mexico is a tiny global producer of heroin, it is catching up to Colombia as the largest source for the U.S. market. Mexican heroin also is being mixed with other drugs to create a stronger and cheaper high – rapidly creating new users of a drug once relegated to hard-core addicts, the officials say.

The result in Dallas is "cheese," a mixture of so-called "black tar" heroin and crushed over-the-counter cold tablets. The product is popular mostly among Hispanic students at northwest Dallas schools who snort the concoction.4

The increased availability of cheap heroin in the Dallas area may have prompted area dealers to find novel ways to market their product, leading to mixture with ground Tylenol PM and a new name. Dealers may refer to their product as "cheese" to conceal the presence of the heroin and avoid its stigma. DEA agent James Capra expressed concern that kids take "cheese" not realizing that it is dangerous or that it contains heroin.5

Demographically, people arrested in association with "cheese" heroin have been primarily Latino and Caucasian.6 It is believed that Mexican gangs form distribution networks bringing heroin into Dallas, which may partially account for the reported high-prevalence of its use among Latinos.

So far, use of "cheese" heroin appears to be confined to the Dallas metropolitan area. As of February 2007, "cheese" heroin has been found in 11 high schools in the Dallas Independent School District (DISD).7 113 students were arrested for "cheese" heroin possession in the DISD from the beginning of the school year in 2006 through February 2007, compared to 130 cannabis-related arrests in the same period.8 This, along with numerous reports of its availability, suggests surprisingly widespread use among high school students in the area.

As of May 2007, the Dallas County medical examiner has reported only 2 deaths associated with a combination of heroin, diphenhydramine, and acetaminophen in 2005, and none at all from 2004 or 2006. Texas Poison Control Centers report only a handful of cases of human exposure to this combination from 1998 through 2005, and 10 exposures in 2006.9 Acetaminophen has a short half-life, so toxicology tests for "cheese" heroin look for diphenhydramine and heroin.6 It is not known if the medical examiner report took this into account.

While reports of the numbers of "cheese"-heroin-related deaths vary significantly, most news reports agree that at least four high school students have died since April 24, 2006 due to overdose.8,10,11 A recent review of the Dallas County medical examiner's office found that the number of "cheese"-heroin-related fatalities may be as high as 18,6 but solid data is not currently available.9 Dallas Morning News reports:

The number of cheese-related deaths has been difficult to determine, largely because the Dallas County medical examiner's office doesn't routinely track drug deaths with its aging computer system. Also, law enforcement doesn't normally compare notes on overdoses, and in Dallas, overdose cases that go straight to the hospital don't usually involve police.3

There is unquestionably a marked increase in heroin-related arrests and fatalities in the Dallas area. However, while several news stories suggest that "cheese" heroin is a new drug that poses a novel threat, it is unclear that "cheese" heroin constitutes a new drug in any meaningful sense. "Cutting heroin with the antihistamine diphenhydramine has long been common," observes Jane Maxwell of the Gulf Coast Addiction Technology Transfer Center, "and sticky black tar heroin has to be cut to be inhaled."12 Maxwell expressed concern about frequent media suggestions that "cheese" heroin is a novel new super-drug, warning that:

Another concern is the continuing widespread publicity about "Cheese" heroin and the potential for it to result in "copy cat" outbreaks in other areas. Unsubstantiated numbers and sensationalistic emphasis in the media about "new highs" or "schoolboy drugs" may magnify what is already a problematic situation.9

While insufflating heroin – particularly in blends of unknown purity – poses serious dangers, some reports about "cheese" heroin may be alarmist. On its face there is no reason to suppose that heroin cut with Tylenol PM is more addictive or stronger than straight heroin or other heroin mixtures. Zachary Thompson, director of Dallas County Health and Human Services, states "The cheese heroin has been the most instantly addictive and deadliest drug ... that we have seen since the crack cocaine epidemic."6 Yet at least least 20 youths overdosed on black tar heroin in a three-year period in the 1990s in the area around Plano, Texas.6

Some government and media reports have claimed that "cheese" heroin is a form of "starter heroin" designed to hook kids.9,13,14 These reports may date back to the widely-circulated report carried in the DEA's Microgram. However, the Poison Control Center reports that the age range of people exposed to heroin, acetaminophen, and diphenhydramine from 1998 to 2005 is 17 – 36, with an average age of 21.6. While the Poison Control Center also reports that six teenagers were exposed to this combination in 2006, this may indicate a sudden increase in popularity of an old drug combination among high school kids rather than the creation of a novel drug calculated to hook kids.

A review of some two dozen reports about "cheese" heroin suggests that the idea of "cheese" took on a life of its own as legitimate fears and news stories multiplied. But, initial indications suggest that there may be nothing particularly novel about "cheese" heroin, beyond its name.