Letter to the Editor

The Prevalence of Dextromethorphan Abuse

Among High School Students

The following Letter to the Editor authored by faculty in the Center for Interventions and Addictions Research was printed in the November 2006 issue of Pediatrics, the official journal of the American Academy of Pediatrics. The entire letter is reprinted below or can be accessed through the journal's web site (Pediatrics 2006; 118: 2267-2269 or PubMed #17079611).

To the Editor:

Dextromethorphan (DXM) is the d-isomer of the codeine analog, levorphanol, and the active ingredient in more than 100 over-the-counter, cough and cold preparations. Reports of DXM abuse date back to the 1960s.1, 2 There is some evidence suggesting that when used inappropriately at very high doses (e.g., 1500 mg per day), DXM can result in a dependence-like syndrome.2 Psychological symptoms of DXM intoxication can include euphoria, an altered sense of time, paranoia, and disorientation as well as tactile, visual and auditory hallucinations. Physical symptoms include but are not limited to hyperexcitabilty, ataxia, and nystagmus.3 These symptoms bear a remarkable similarity to those seen with phencyclidine (PCP), a powerful dissociative anesthetic that has also been abused since the 1960s.4 Research on the pharmacology of DXM shows that it is metabolized by the liver enzyme CYP2D6 to dextrophan, a metabolite with an affinity for NMDA receptors, which explains the PCP-like effects that can result from consuming higher than recommended doses of the drug.5, 6 Earlier research suggested DXM abuse was sporadic and declining;7 however, recent case reports about its misuse have again raised concern about the purposeful ingestion of DXM for its consciousness altering properties, particularly among young people.8-10 In addition to calling attention to the dangers of DXM abuse, some observers have highlighted the role of the Internet in facilitating the abuse of the drug.11 Still, the scope of DXM abuse among adolescents is unknown. To address this issue, we report the results of a recently conducted survey of high school students in a mid-sized, midwestern community that assessed the prevalence of DXM abuse.

The Dayton Area Drug Survey (DADS) is a biennial, cross-sectional study that provides estimates of teen drug use for schools and the community. In early 2006, 7th-12th grade students in 15 school districts in the Dayton, Ohio, area participated in the DADS. Students responded anonymously and voluntarily in classroom settings to DADS questions on computer-scanable answer forms. Data were collected in accordance with a protocol approved by the university's IRB. More information on the DADS methodology is available elsewhere.12 In addition to the DADS standard multiple choice items on commonly abused drugs, for the first time supplemental questions focusing on DXM were included in the survey and asked of 11th and 12th grade students only. Specifically, these students were asked, "On how many occasions (if any) have you used DXM, sometimes called DM, Triple C, Tuss, Robo, to get high or intoxicated in your lifetime?" with never, 1-2, 3-5, 6-9, 10-19, and ≥ 20 as response options. A similar question was asked to assess use in the 12 month time period prior to the survey. More than 4000 students responded to these two questions. The majority of responders were white (85%), suburban (95%), and almost evenly split between boys (49%) and girls (51%).

Among 12th grade students (n=2437), 4.9% reported lifetime use of DXM and while 3.7% reported abuse in the past 12 months. Among 11th grade students (n=1739), 3.4% reported lifetime use, 2.4% in the past 12 months. Among 12th graders who reported use, 55% had used it 3 or more times; among 11th graders, 33.9% had. We used X 2 tests to identify potential differences between those students who reported having used DXM at least once in their lifetimes for non-medical purposes with those students who had not. Results show that significantly more boys than girls used the drug (P = .002) but there were no significant differences in use between whites and non-whites (P = .93). Virtually no DXM abuse was reported by African-American or Asian-American girls. In the 30 days before the survey, proportionately more DXM abusers smoked a half pack of cigarettes or more per day (P = .0001), got drunk on alcohol more than twice (P = .0001), and smoked marijuana more than twice (P = .0001) than did non-users. In addition, proportionately more DXM abusers reported lifetime experience with drugs like LSD or psilocybin (P = .0001) and MDMA/ecstasy (P = .0001) than did non-users. For example, among 12th grade DXM users, 69.2% reported the lifetime use of LSD or psilocybin, compared to 6 .7% of non-DXM users.

To help avoid the potential of stimulating interest in DXM as a recreational drug, we chose not to use the brand names of products known to be commonly abused, such as Robitussin© or Coricidin®, in the survey questions. For similar reasons, we also chose not to survey students in earlier grade levels about the drug. Consequently, abuse of the drug among teenagers may be more widespread than our data show. Regardless, the lifetime prevalence of DXM abuse among high school seniors in the Dayton area exceeds that associated with anabolic steroids (2.2%), MDMA (4.0%), heroin (4.1%), crack cocaine (4.4%) and Ritalin® (4.8%), and rivals methamphetamine (5.5%).

To the best of our knowledge, this is the first large scale epidemiological study of the non-medical use of DXM among youth. Our results suggest that significant numbers of adolescents are abusing DXM. Given the plethora of dangers associated with consuming the drug for recreational purposes and in excess of its recommended dosage levels, and difficulty detecting it in urinalysis,11, 13 it may be prudent to again consider restricting the availability of the drug. An informational campaign about DXM abuse targeting parents of teenagers might also be appropriate. Pediatricians and emergency department physicians should be aware of the fact that the recreational use of DXM among teenagers is more common than case reports on its abuse might suggest.

Russel Falck, M.A.
Linna Li, M.S.
Robert Carlson, Ph.D.
Jichuan Wang, Ph.D.

Department of Community Health
Center for Interventions, Treatment & Addictions Research
Wright State University Boonshoft School of Medicine
Dayton, OH 45435

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