by Kate Lu and Donald M. Pizzi

The rates of emergency department (ED) visits involving nonmedical use of prescription drugs—particularly opioid analgesics and benzodiazepines—increased dramatically from 2004 to 2008, with the inappropriate use of prescription and over-the-counter medications accounting for all of the growth of overall drug misuse and abuse rates for those years. This is according to a new study done by the Centers for Disease Control and Prevention (CDC) and the Substance Abuse and Mental Health Services Administration (SAMHSA).

As a result of the study report—published in Morbidity and Mortality Weekly Report (2010; 59:705-709)—the CDC has acknowledged that efforts to prevent misuse of these drugs have not been effective, calling for “stronger measures to reduce the diversion of prescription drugs to nonmedical purposes.”

Investigators from the CDC used data from SAMHSA’s Drug Abuse Warning Network (DAWN), which tracks the use (as well as misuse) of drugs by monitoring ED visits in the United States. Information was collected from approximately 220 hospitals covering 2004 to 2008, the most recent five years for which data were available. The DAWN review showed that the number of ED visits for the nonmedical use of opioid analgesics increased 111% during the five-year period; the number of ED visits for the nonmedical use of benzodiazepines rose 89% during that period.

An estimated 1.6 million ED visits for the misuse and abuse of drugs occurred in 2004, according to DAWN; by 2008, that number had increased to 2 million. Illicit drugs were involved in 1 million cases in both 2004 and 2008, but prescription and over-the-counter drugs used nonmedically accounted for 500,000 visits in 2004 but rose to 1 million visits in 2008.

The number of cases involving the nonmedical use of opioid analgesics increased from 144,600 in 2004 to 305,900 in 2008 (P<0.001), with the highest number of ED visits recorded for oxycodone, hydrocodone and methadone (Figure). Cases involving the nonmedical use of benzodiazepines increased from 143,500 in 2004 to 271,700 in 2007 (P=0.01), with alprazolam, clonazepam, diazepam, lorazepam and zolpidem the most common agents in this class involved. The researchers further found that 26% of ED visits involving opioid misuse also involved benzodiazepines. What’s more, one in four ED patients misusing opioids and/or benzodiazepines was ultimately admitted to the hospital.

Over the five years studied, the largest increases in misuse or abuse rates of prescription drugs occurred in people aged 21 to 29 years—reflecting a shift away from the 35- to 54-year-old group. In 2008, the misuse rates for both opioid analgesics and benzodiazepines increased sharply after age 17 years and peaked in the 21- to 24-year age group before declining after age 54.

The dramatic increase in opioid- and benzodiazepine-related ED visits seen in this study are in part due to tremendous jumps in the prescribing of these drug classes during the five-year period—CDC estimates put the number of pain patients in the United States using opioids long-term to manage their conditions at 8 million, a marked increase from just a decade ago. In an editor’s note accompanying the CDC report, it was theorized that some of the increase in ED visits must be attributed to recent spikes in the rate of nonmedical use of opioids per 1,000 prescriptions.

Potential liabilities of the study, according to the report, were as follows:

• Whereas documentation and identification of specific misused drugs have no doubt improved in the ED setting, there was no assurance that the specific drug had been accurately identified in all cases in the study.
• It is impossible to definitively know the reason behind each ED visit, with some of visits potentially resulting from suicide attempts.
• Population-based rates cannot be used to gauge risk for individual patients.

It is not always possible to know, beyond a reasonable doubt, whether a drug is being used for medical or nonmedical purposes.

Results Unacceptable

The editor’s note was critical of current efforts to curb abuse of prescription medications, describing them as failing in their intended purpose.

“These increases in nonmedical use of pharmaceuticals suggest that previous prevention measures, such as provider and patient education and restrictions on use of specific formulations, have not been adequate,” the CDC maintained. The report suggests that additional, stronger intervention measures are needed to reduce the abuse of prescription medications, including:

• increased and “systematic” provider education;
• universal use by providers of state prescription drug monitoring programs;
• routine monitoring of insurance claims “for signs of inappropriate use”; and
• interventions on the part of provider and insurers in cases of inappropriate prescription drug use.

“This report also reinforces the value of timely, population-based national surveillance for nonmedical use of drugs,” wrote the CDC, “which can be used to assess the effects of such interventions.”