Do Warning Labels Work?

While illicit drug use in the United States is certainly a public health concern, the increasing use of legal, over-the-counter (OTC) drugs for non-medical use is alarming. The most recent data available from the 2006 National Survey on Drug Use and Health reports that 3.1 million people aged 12 to 25 years had used an OTC drug to get high. Dextromethorphan (DXM) — a cough suppressant available in nearly 150 OTC products — is the biggest target of misuse. Now, the Consumer Healthcare Products Association (CHPA) is voluntarily placing warning labels on DXM-containing products to caution buyers about teen medicine abuse.

DXM is readily available, easily accessible, and inexpensive; it is safe and effective at clinical doses. However, when ingested in large quantities — usually greater than 2 mg/kg of body weight — the drug can display physical and psychological effects similar to ketamine and phencyclidine (PCP). Massive doses of DXM can cause increased heart rate, extreme high blood pressure, and respiratory depression. DXM can also cause the dissociative effects seen with hallucinogens. Treatment of DXM overdoses is primarily supportive, and antidotes to DXM have limited success in reversing the effects of an overdose.

The CHPA is responding to increased public awareness and concern for the issue of teen medicine abuse, but the effectiveness of the campaign remains to be determined. In addition to labeling all brand name and generic products containing DXM with the warning logo, which will begin appearing on pharmacy shelves later this year, the CHPA has also established a website ( to educate consumers and parents about the risks of DXM abuse. The website offers handbooks and drug abuse resources, links to other organizations, access to newsletters, and connections to social networking sites. But, will allowing parents to download widgets and icons onto their Facebook or Twitter accounts really stop teens from misusing drugs?

The goal of the CHPA — to increase awareness and education about a growing public health concern — is admirable, but may be misdirected. Research concerning the effectiveness of warning labels is mixed, and some data suggests that people who read warning labels are already health conscious and attentive to health warnings. Factors influencing the effectiveness of warning labels include characteristics of the icon itself (font, color, size, etc.), consumer familiarity with the product, and the age of the consumer. And, even if warning labels reach teenagers, they may not influence the behavior, because younger audiences may not fully appreciate the risks associated with DXM abuse or be influenced to change their attitude or behavior. Other research has shown that the effects of health warnings on packaging labels cannot be differentiated from concurrent community education programs.

Warning labels are everywhere — cigarettes, alcohol, music, television; they have been put in place due to changing regulations, public safety concerns, and mounting lawsuits. Now, will another warning label be eye-catching and effective, or just another image to glance over in a society in which we are constantly overloaded with stimuli?


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Jennifer Gibson, PharmD

Jennifer Gibson, PharmD, is a practicing clinical pharmacist and medical writer/editor with experience in researching and preparing scientific publications, developing public relations materials, creating educational resources and presentations, and editing technical manuscripts. She is the owner of Excalibur Scientific, LLC.
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