Drug-Related Emergency Department Visits Involving Synthetic Cannabinoids

Synthetic cannabinoids are substances that are designed to affect the body in a manner similar to marijuana but that are not derived from the marijuana plant.¹ Because they can be purchased with no age restrictions, their popularity among young people has grown.²

Synthetic cannabinoids are known by a variety of names, such as "Spice" or "K2," and sometimes are referred to as "synthetic marijuana" or "fake marijuana" because they are marketed with claims that their effects mimic those of marijuana. Synthetic cannabinoids are typically sprayed onto herbal products, many of which are listed as inactive on the product packaging.²

Although certain synthetic cannabinoids and/or specific chemicals contained in these preparations were made illegal in some States, a comprehensive national ban was not enacted until July 2012.³ Therefore, products containing synthetic cannabinoids were frequently marketed as "legal" and "not for human consumption" and could be purchased online and in legal retail outlets such as convenience stores.¹

Because products marketed as synthetic cannabinoids contain different ingredients from each other, it is difficult to identify which physical effects are caused by synthetic cannabinoids.⁴ They have been reported to cause agitation, anxiety, nausea, vomiting, tachycardia, elevated blood pressure, tremor, seizures, hallucinations, paranoid behavior, and nonresponsiveness.^2,5 These products are relatively new, and related clinical and public health outcomes have not been fully examined. Synthetic cannabinoids are not currently identified using routine screening tests, and the creation of new products of this type makes it difficult to detect these chemicals or regulate these products.

The Drug Abuse Warning Network (DAWN) first detected a measurable number of emergency department (ED) visits involving synthetic cannabinoids in 2010, and this report presents data related to these visits.⁶ DAWN is a public health surveillance system that monitors drug-related ED visits in the United States. To be a DAWN case, an ED visit must have involved a drug, either as the direct cause of the visit or as a contributing factor.

Of the approximately 2,300,000 ED visits that involved drug misuse or abuse in 2010, synthetic cannabinoids were specifically linked to an estimated 11,406 visits. This issue of The DAWN Report examines ED visits involving synthetic cannabinoid products in 2010 among patients aged 12 to 29. The report focuses on this age group because ED visits involving synthetic cannabinoids are concentrated in this age range (8,557 visits, or 75 percent of all visits involving synthetic cannabinoids, were made by patients aged 12 to 29 in 2010).

For patients aged 12 to 29, males made more than three quarters (78 percent) of ED visits involving synthetic cannabinoids in 2010 (Figure 1). The rates of visits per 100,000 population for patients aged 12 to 17, 18 to 20, and 21 to 24 were similar (14.9, 13.9, and 11.8 visits per 100,000 population, respectively) (Table 1). However, the rate for those aged 25 to 29 (4.1 visits per 100,000 population) was lower than those for patients aged 12 to 17 (14.9 visits per 100,000 population) and those aged 18 to 20 (13.9 visits per 100,000 population).

In the majority (59 percent) of ED visits involving synthetic cannabinoids for patients aged 12 to 29, no other substances were involved (Figure 2). This differs from ED visits involving other illicit drugs or nonmedical use of pharmaceuticals, in which the majority of visits involved multiple drugs.⁷ Synthetic cannabinoids were used in combination with one other substance in 36 percent of visits related to their use, but were rarely used in combination with two or more substances (6 percent). The types of drugs most frequently used in combination with synthetic cannabinoids were marijuana (17 percent), pharmaceuticals (17 percent), and alcohol (13 percent).

Among ED visits involving synthetic cannabinoids made by patients aged 12 to 29 in 2010, it appears that the majority (76 percent) did not receive follow-up care (admission to the hospital, transfer to another health care facility, or referral to a detoxification/treatment program). Most of the 2,077 visits resulting in follow-up care involved synthetic cannabinoids in combination with other substances (75 percent).

Because synthetic cannabinoids have been marketed as a legal alternative to marijuana, this section will provide a brief comparison of the patient characteristics of ED visits between marijuana and synthetic cannabinoids. Marijuana-related ED visits outnumber synthetic cannabinoid-related visits (461,028 vs. 11,406 visits). The average patient age for marijuana-related visits was 30 years and the average patient age for synthetic cannabinoid-related visits was 24 years. The age distribution also differed between the two drugs. Synthetic cannabinoid-related visits were concentrated in the younger age groups: 75 percent of the visits involved patients aged 12 to 29, with 33 percent of the patients aged 12 to 17. In comparison, 58 percent of marijuana-related visits involved patients aged 12 to 29, with 12 percent in the 12 to 17 age group (Figure 3).

When patients in the 12 to 29 age range were compared, synthetic cannabinoid-related ED visits were more likely to involve male patients than were marijuana-related visits (78 vs. 66 percent) (Figure 4). Further, synthetic cannabinoids were more likely to be the only drug implicated in the visit, whereas marijuana was more frequently combined with other drugs (59 vs. 31 percent, respectively; data not shown).

As synthetic cannabinoids have become more available, the number of ED visits involving synthetic cannabinoids has increased. The higher proportion of ED visits in younger age groups, especially in patients aged 12 to 17, combined with results from a national survey of high school seniors revealing that 11 percent reported using "synthetic marijuana" in 2011, is cause for concern.⁸ Because it is difficult to regulate these products that are easily available online, synthetic cannabinoids may be more accessible to young people than marijuana.⁹ Educators can help prevent use of synthetic cannabinoids by addressing use of these substances in programs designed to prevent use of illicit drugs. Parents can also discuss the dangers of these drugs with their children and use parental controls for online purchases.

Because of limited availability of tests for synthetic cannabinoids, data collection efforts in the ED may have missed visits in which they were involved. However, even in the absence of positive drug test results, health care providers can remain alert to symptoms that may be attributed to synthetic cannabinoids and, when appropriate, inquire about their use.⁴ Further monitoring will be necessary to determine whether synthetic cannabinoid-related health problems continue to be reported. This monitoring can help improve awareness among health care professionals of the possible adverse health effects of these substances. Because most synthetic cannabinoid-related ED visits result in discharge from the ED, a patient's time in the ED is a valuable opportunity for intervention and education.