Most Utah residents receiving prescriptions for opioid painkillers did not immediately use all the medication they were given and, against recommendations, kept the leftovers, researchers said.

Of 5,330 Utah citizens participating in the annual Behavioral Risk Factor Surveillance System survey in 2008, 20.8% (95% CI 19.2% to 22.3%) reported having used opioid pain medications prescribed by a physician, Christy Porucznik, PhD, MSPH, of the University of Utah, and colleagues, wrote in the Feb. 19 Morbidity and Mortality Weekly Report.

Some 72% (95% CI 68.3% to 75.7%) indicated that they didn't use all the medication they had received, and of these, only 25.2% (95% CI 21.0% to 29.5%) reported that they had followed recommendations to dispose of the unused drug.

The FDA and state authorities recommend that patients with unused opioid medications should flush them down the sink or toilet.

More than two-thirds of the survey respondents with unused opioids -- 71.0% (95% CI 66.4% to 75.6%) -- said they had kept the leftovers.

Other types of misuse were much less common, the survey results suggested:

    * 2% gave leftover opioids to someone else
    * 3.2% used the medications more frequently or in higher doses than prescribed
    * 1.8% used opioids not prescribed to them

Hydrocodone and oxycodone accounted for nearly all the legitimate opioid use in the survey, with 69.3% and 27.5% of prescriptions, respectively.

Most respondents, 71%, said the prescriptions were for short-term pain.

Of those using opioids not prescribed to them, about three-quarters reported using the drugs for pain. Only 15% said their use was recreational. About 10% indicated they had stolen the medications, and 4% said they had bought it illicitly.

In an accompanying unsigned commentary, MMWR's editors said the reported prevalence of opioid use in Utah was consistent with national survey results: some 18.4% of insured adults in 2002 indicated they had received an opioid prescription. They also noted earlier findings that Utah -- despite its reputation for abstemiousness with regard to caffeine and alcohol -- has had the nation's highest rates of nonmedical use of painkillers.

The editors added that the new survey results may indicate how Utah and other states can fight a recent upswing in poisonings from prescription pain drugs. In Utah, the number of overdose deaths increased seven-fold from 1999 to 2007.

"Although the extent to which leftover medications contribute to overdose deaths is unknown, the 1.8% of respondents who reported using prescription opioids that had not been prescribed to them extrapolates to approximately 35,000 adults in Utah engaged in illegal and risky behavior," the MMWR editors pointed out.

The very existence of leftover medications suggests that physicians are prescribing more doses than patients need, the editors wrote.