Seeking to expand access to one of the few drug treatments for opioid addiction, Minnesota Attorney General Lori Swanson took several steps Thursday to increase production of the drug, reduce prices and remove insurance barriers.

Joining attorneys general from 34 other states, Swanson sued Indivior, a Virginia-based drug manufacturer, to halt practices that have prevented the development of a generic version of its drug Suboxone.

Separately, Swanson wrote to Minnesota’s major health insurers, asking them to eliminate prior authorization rules that prevent some addicts from getting the drug.

“I am concerned about any barriers that make it more difficult for people to access this potentially lifesaving drug and escape opioid dependence,” Swanson said in a statement released Thursday afternoon.

Suboxone reduces cravings for prescription opioids and illegal versions such as heroin, which have been increasingly abused in the United States over the past 20 years. Minnesota reported 336 deaths last year linked to excessive or abusive use of opioids — a sixfold rise since 2000.

In Minnesota, access to Suboxone has been limited by the relatively small number of doctors who have completed the required federal certification training, in part because they haven’t been eager to become regional treatment providers for opioid addicts.

But access has expanded. Even Minnesota’s Hazelden Betty Ford Foundation, which generally promotes abstinence to treat addiction, added Suboxone to its opioid treatment program recently due to the challenging nature of such addictions.