Doctors, schools and law enforcement have been concerned about young people abusing the active ingredient in many over-the-counter cough remedies -- but the medicines will likely remain available without a prescription.
A U.S. Food and Drug Administration advisory panel voted today against requiring prescriptions for dextromethorphan (DXM), which was responsible for an estimated 7,988 emergency department visits in 2008, up from 4,634 in 2004, according to FDA documents. The panel opposed regulating it under the Controlled Substances Act.
The FDA usually follows advisory panel suggestions, but is not bound by them. Congress still could move to limit sales to anyone under the age of 18.
The Consumer Healthcare Products Association, which represents over-the-counter drug makers, applauded the panel's decision.
"Today's FDA advisory committee decision not to recommend scheduling OTC cough medicines containing dextromethorphan as a controlled substance reflects a sound balancing of the benefits of over-the-counter medicines containing dextromethorphan," the group said in a statement.
"We do, however, recognize the need for continued education to keep any abuse levels low."
More than 120 cough preparations contain DXM, which received FDA approval in 1958 as a non-addictive replacement for codeine and has undergone multiple safety reviews. Considered safe and effective at recommended doses with minimal adverse effects, DXM has become the most widely used cough suppressant in the United States.
Among the best-known brands containing DXM is Robitussin. Some teens and tweens have told of going "Robo tripping," swallowing large doses of Robitussin in search of a cheap high.
Other nicknames for DXM-containing pills, tablets, gel capsules or powders include "robo," "tussin," "dex," "rojo" and "red velvet." Coricidin HBP Cough & Cold, sometimes called "Triple C" for the three C's imprinted on the red tablets, contains some of the highest DXM doses of any non-prescription cough product.
DXM doesn't make for a very pretty high. At recommended doses of up to 30 milligrams for coughs, it can produce nausea, digestive disturbances, drowsiness and dizziness. At doses of 250 to 1,500 mg, typically taken by abusers, it can produce blurred vision, itching, rash, sweating, fever, and shallow breathing as well as increased blood pressure, heart rate and body temperature. It also can produce hallucinations, loss of motor control and in some cases, death, according to the American Society of Anesthesiologists (ASA), which released guidelines in July to help parents recognize signs that their children might be Robo tripping.
Dr. Michael H. Entrup, an ASA board member and an anesthesiologist in Providence, R.I., said in an interview that he's been warning parents for years about the abuse of DXM. The father of three college-age children, he said he's become particularly worried about DXM because many youngsters today combine it with prescribed stimulants for ADHD.
"You have a larger portion of high school and college kids taking stimulants," Entrup said. "The combination with the dextromethorphan is actually more deadly." Entrup also voiced concern about combining DXM with energy drinks like Red Bull. "All these stimulants have not just additive effects, but some have synergistic effects."
The combinations at first give them a quicker high, but then can suppress their breathing and heart function, which is very dangerous.
Speaking only for himself and not the ASA, Entrup said he wouldn't support making DXM a prescription-only cough remedy because it's generally safe. But he would support restrictions keeping it out of the hands of those under 18: "I personally feel that it should be [restricted], just as any other type of medication. I think there should be warnings about combining these types of things."
Death from DXM abuse is rare, because high doses often induce vomiting, but most deaths are caused by taking DXM in combination with other medications. Health officials worry about combining it not only with stimulants, but also with some classes of antidepressants, which can cause life-threatening serotonin syndrome, which requires hospital treatment.
These dangers have been on the radar screen of the American Association of Poison Control Centers, which published guidelines on out-of-hospital management of DXM poisoning in the journal Clinical Toxicology in September 2007; emergency room doctors say DXM poisoning can come from a single overdose, or chronic usage.
In hundreds of pages of briefing materials posted by the FDA in advance of Tuesday's Drug Safety and Risk Management Advisory Committee hearing, agency scientists analyzed sales and abuse of products containing DXM.
"Although DXM abuse has been recognized since the 1960s, the drug's misuse has become more common. The drug is abused by individuals of all ages, but its abuse by teenagers and young adults is of particular concern," scientists wrote. They said its "perceived safety, ease of availability, and desired psychoactive effects" make it an easy means of getting high.
In an August 2010 fact sheet included in the hearing briefing materials, the Drug Enforcement Administration warned that DXM abuse is fueled by easy access and "extensive 'how-to' abuse information on various websites."
Even former users said it was easy to find the levels at which DXM produces mind-altering effects: 100-200 mg for mild stimulation, 200-400 mg for euphoria and hallucinations. In May 2005, writer Jennifer Henley Daniel offered her own reflections on Robo-tripping when she was 16.
In that piece, posted on the now-defunct Arriviste Press website, Daniel said the website of the National Drug Intelligence Center tells you "everything you need to know about procuring DXM and abusing the hell out of it." Daniel said she found particularly helpful photos of "all the DXM-containing products, along with other possibilities to be found on the streets -- like the tablets containing a mixture of ketamine and DXM." She said the website, however, had "no images of dead 14-year-olds or after-school-special testimonies from hospital patients bleeding from their eyeballs after eating too much Coricidin HPB."
The Consumer Healthcare Products Association, which represents manufacturers, opposes any restrictions on sales to adults. In the CHPA Briefing Book filed with the FDA before Tuesday's hearing, CHPA said non-prescription dextromethorphan gives millions of Americans relief from coughing.
"The accessibility of dextromethorphan OTC allows individuals and family caregivers to quickly and effectively counter the negative impact of cough on their own and their family's life, thereby enabling them to continue with their work and private duties." The organization said that limiting sales under the Controlled Substances Act "would restrict its legitimate medical use as a self-treatment for cough," and predicted that eliminating the option to self-medicate with dextromethorphan "would probably have substantial public health consequences in terms of an increased utilization of healthcare system resources for acute cough and cold conditions and an increased use of non-equivalent alternative treatments."
However, the CHPA called age restrictions to curb teen access "a reasonable and potentially effective approach given the highest prevalence of abuse is among teens."