There is no solid research showing that long-term opioid use is an effective treatment for chronic pain, a National Institutes of Health panel has determined.

The findings could undermine arguments from long-term care providers, who protested recent regulatory changes that restricted opioid access. Providers said that many residents rely on timely access to these drugs, such as Vicodin, to manage their ongoing pain.

Existing scholarly literature does not show that these potentially addictive drugs are especially good at treating chronic pain for periods of a year or more, the seven-member NIH panel found. The group’s report is based on a two-day hearing with an independent agency that reviewed available English-language studies on this topic.

Skyrocketing prescriptions for opioids are hard to understand in light of the existing research, stated panelist David Steffens, M.D., a University of Connecticut geriatric psychiatrist. He acknowledged that opioids do seem to work well for certain patients, but he argued that best practices for opioid prescribing need to be more firmly established.

Steffens called opioid reliance a “peculiarly American problem,” because the United States consumes 80% of the world’s opioid drug supply. Opioid overdose deaths exceeded 16,000 in 2012, and the Centers for Disease Control and Prevention has said prescription opioid abuse is epidemic.

The situation prompted the recent reclassification of the drug. The change is likely to be permanent, and providers already are adjusting their medication management to ensure that residents have necessary pain relief, long-term care pharmacy experts recently told McKnight’s.

Complete findings appear in the online version of the Annals of Internal Medicine.