By Lisa Girion, Los Angeles Times

Fatal overdoses involving prescription painkillers have increased every year for more than a decade, but a government study has found for the first time that the rate is slowing.

Before 2006, the age-adjusted rate of painkiller-involved deaths grew by 18 percent per year, according to a report issued Tuesday by the National Center for Health Statistics. Since then, however, the death rate increased by 3 percent per year, the study found.

But the encouraging trend was not uniform. The number of deaths involving OxyContin, Vicodin, and other widely prescribed opioid painkillers continued their steady and steep climb through 2011, the last year included in the analysis.

The slowdown was driven largely by a decrease in overdoses involving methadone, the study said. Methadone is an opioid that is both prescribed by doctors for pain relief and dispensed at clinics to help recovering addicts stay off heroin and other narcotics.

Over the 12-year period from 1999 to 2011, the age-adjusted rate of painkiller deaths nearly quadrupled, reaching 5.4 per 100,000, according to the report. That translated to 16,917 deaths in 2011.

The greatest increases occurred among people aged 55 to 64 and non-Latino whites.

The study also highlighted the growing role of anti-anxiety drugs, known as benzodiazepines. Xanax, Valium, and other benzodiazepines were involved in 31 percent of the painkiller deaths, up from 13 percent in 1999.

The National Center for Health Statistics is part of the Centers for Disease Control and Prevention.

Photo: epSos.de via Flickr

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