Issue 29, 2006

Emergency Department Visits Involving ADHD Stimulant Medications

Recent studies have indicated that as many as 7 percent of children and 4 percent of adults now meet the criteria for a diagnosis of attention-deficit/hyperactivity disorder (ADHD).^1,2,3 As a result, more prescriptions are being written for the stimulants used to treat ADHD. More prescriptions will likely lead to increases in medical side effects associated with the use of these medications and, potentially, greater use of these drugs for nonmedical purposes as well.⁴ A recent Food and Drug Administration (FDA) advisory panel recognized the danger of side effects for ADHD stimulants and recommended that they carry a warning of an increased potential for cardiac problems, such as hypertension, cardiac arrests, and stroke.⁵ The possibility of medical problems may be exacerbated by using ADHD stimulant medications improperly or in combination with other drugs.

The potential for greater access of these medications to persons without a prescription is supported by research, which has shown that peers are a common source of ADHD medications.⁶ Although the potential for diversion has increased, estimates from the 2003 National Survey on Drug Abuse and Health (NSDUH) indicate that nonmedical use of ADHD stimulant medications is still relatively low: 0.3 percent of the population aged 12 or older reported using such stimulants nonmedically during the past year. However, those aged 18 to 25 had a higher rate of nonmedical use than those who were younger or older.⁷ College students, who may use these drugs as study aids because of their stimulant properties, fall primarily in this 18-to-25 age group.

The Drug Abuse Warning Network (DAWN), which collects data from a national sample of short-term, general, non-Federal hospitals,⁸ provides estimates of drug-related emergency department (ED) visits. The findings presented in this issue of The DAWN Report are based on ED visits related to two of the pharmaceuticals commonly used to treat ADHD—methylphenidate and amphetamine-dextroamphetamine. DAWN includes both generic and branded drugs, including methylphenidate marketed as Ritalin^© and Concerta^© and amphetamine-dextroamphetamine marketed as Adderal^©. Based on DAWN data, this report examines the reasons for the ED visits and the relative frequency of these ED visits for different age groups. Finally, for the ED visits involving nonmedical use, DAWN provides the ability to examine the drugs used along with the ADHD drugs. DAWN, which observes drug-related morbidity in ED visits, offers a different view of drug use than the NSDUH, which measures prevalence of nonmedical use in the population at large.

In 2004, about 106 million ED visits occurred in short-term, general, non-Federal hospitals in the United States.⁹ DAWN estimates that about 2 million ED visits in 2004 were drug related, and the ADHD drugs examined in this report were implicated in under 1 percent of those drug-related visits. Methylphenidate was involved in an estimated 3,601 ED visits, and amphetamine-dextroamphetamine was involved in an estimated 4,272 ED visits.

Among the 7,873 ED visits involving one of the ADHD medications, nonmedical use accounted for 48 percent of the visits and medical use (i.e., adverse reaction) accounted for 34 percent (Table 1). Nonmedical use includes cases when a higher than prescribed dose was used, a drug prescribed for another person was used, or there was other evidence in the medical record of drug misuse or abuse. Considerably fewer of the ED visits were associated with accidental ingestion (10%) or suicide attempt (8%).¹⁰

As mentioned above, findings from the NSDUH suggest that nonmedical use of ADHD drugs is more frequent among those aged 18 to 25 than among younger (e.g., 12 to 17) or older (26 or older) age groups. DAWN estimates show that the rate of ED visits involving ADHD stimulants is highest among patients aged 12 to 17 (Figure 1). This pattern is found for both medical and nonmedical use of these stimulants. These findings suggest that younger persons (aged 12 to 17) are at greater risk for adverse health effects, despite being less likely than those aged 18 to 25 to use ADHD drugs nonmedically.

Figure 1. Rates of ED visits, by drug, type of use, and age
Source: Office of Applied Studies, SAMHSA, Drug Abuse Warning Network, 2004 (09/2005 update).

ED visits involving adverse reactions associated with medical use usually involve only a single drug. For methylphenidate or amphetamine-dextroamphetamine, about three quarters (77%) of adverse-reaction visits involved only the single drug.

For ED visits associated with nonmedical use, polydrug use is typical. This is important because the combination of ADHD medications with alcohol, illicit drugs, and other pharmaceuticals may amplify the health risks.

Multiple drugs were present in about two thirds (68%) of the nonmedical-use visits involving methylphenidate or amphetamine-dextroamphetamine (Table 2). Alcohol was present in 20 percent of visits, illicit drugs in 26 percent, and other pharmaceuticals in 57 percent.

1. Robison, L.M., Sclar, D.A., Skaer, T.L., & Galin. R.S. (1999). National trends in the prevalence of attention-deficit/hyperactivity disorder and the prescribing of methylphenidate among school-age children: 1990-1995. Clinical Pediatrics, 38(4), 209-218.
2. Wender, P. H. (1998). Pharmacotherapy of attention-deficit/hyperactivity disorder in adults. Journal of Clinical Psychiatry, 59 (supp. 7), 76-79.
3. Kessler, R.C., Adler, L., Barkley, R., Biederman, J., Conners, C.K., Demler, O., Faraone, S.V., Greenhill, L.L., Howes, M.J., Secnik, K., Spencer, T., Ustun, T.B., Walters, E.E., & Zaslavsky, A.M. (2006). The prevalence and correlates of adult ADHD in the United States: Results from the National Comorbidity Survey Replication. American Journal of Psychiatry, 163, 716-723.
4. Cohen, A. L., Jhung, M.A., & Budnitz, D.S. (2006, May 25). Stimulant medications and attention deficit-hyperactivity disorder. New England Journal of Medicine, 354(21), 2294-2295.
5. U.S. Department of Health and Human Services, Food and Drug Administration. (2006, January 6). Drug Safety and Risk Management Advisory Committee; Notice of Meeting. Washington, DC: Federal Register, 71(4), 942.
6. McCabe, S.E., & Boyd, C.J. (2005). Sources of prescription drugs for illicit use. Addictive Behaviors, 30(7), 1342-1350.
7. Kroutil, L.A., Van Brunt, D.L., Stahl, M.H., Heller, D.C., Bray, R. M., & Penne, M. A. (in press). Nonmedical use of prescription stimulants in the United States. Research Triangle Park, NC: RTI International.
8. Specialty hospitals, including children's hospitals, are excluded from the DAWN sample.
9. AHA Annual Survey Database, Fiscal Year 2003. Health Forum LLC, Copyright 2004, One North Franklin Street, Chicago, IL 60606.
10. DAWN does not collect data on preexisting conditions, so it is not possible to know whether a specific drug or a preexisting condition, such as depression, contributed to the suicide attempt.