Thirty-five states and Washington, D.C., are accusing opioid drugmaker Indivior of trying to keep generic versions of Suboxone off the market, reports Reuters.
The drug, made by Indivior, is used to treat pain as well as addiction to narcotic pain relievers.
In a lawsuit filed by the entities Thursday, they allege British company Indivior made efforts to get patients to switch to a dissolvable oral strip version of Suboxone.
The lawsuit alleged that when Indivior's exclusive right to sell the drug was about to expire in 2009, it took steps to block generic versions from entering the market and that another company, MonoSol Rx, helped Indivior reach that goal, according to the report.
Indivior said in a statement cited by Reuters that it would continue to "vigorously defend" its position.