NORMAN, Okla.  — The nation’s first state trial against drugmakers blamed for contributing to the opioid crisis started Tuesday in Oklahoma in a case that could shape negotiations to resolve the roughly 1,500 other opioid lawsuits consolidated before a federal judge.

Oklahoma Attorney General Mike Hunter started opening statements by saying powerful painkillers have led to the “worst manmade public health crisis” in U.S. history. The state alleges drugmakers extensively marketed highly addictive opioids for years in a way that overstated their effectiveness and underplayed the risk of addiction.

“This crisis is devastating Oklahoma,” Hunter said, adding that opioid overdoses killed 4,653 people in the state from 2007 to 2017.

Drugmakers deny Oklahoma’s claims. The companies maintain that they are part of a lawful and heavily regulated industry that is subject to strict federal oversight, and that doctors are the ones who prescribe the drugs. Much of the opioid crisis, they argue, is the result of illegal activity, such as drugs being stolen or obtained fraudulently.