The pharmaceutical giant Johnson & Johnson ran a “false and dangerous” sales campaign that caused addiction and death as it drove America’s opioid epidemic, an Oklahoma court has ruled in the first judgement of its kind against the drug industry.

In a damning 42-page decision, Judge Thad Balkman ruled that the company bore a wide responsibility for helping to create the worst drug epidemic in US history. He said it not only aggressively pushed false claims about the safety and effectiveness of its own narcotic painkillers, but that it changed medical practice with “deceptive” claims intended to break down caution among doctors about prescribing opioids. That included using its huge resources to fund organisations and research to promote narcotics.

Balkman ordered the company to pay $572m in compensation initially with additional payments to be negotiated to cover treatment, overdose prevention and other costs of abating the epidemic in Oklahoma in the coming years. The state had asked for $17bn.

Johnson & Johnson said it will appeal.

The verdict is a blow to a raft of other opioid makers, distributors and pharmacy chains facing more than 2,000 other lawsuits by communities across the country, as it will undercut their attempts to pin blame for an epidemic that has claimed more than 400,000 lives over the past two decades on doctors who prescribed opioids or those who used them.

Oklahoma’s attorney general, Mike Hunter, said the ruling confirmed his claim that “Johnson & Johnson maliciously and diabolically created the opioid epidemic in our state”, contributing to 6,000 deaths in Oklahoma alone since 2000.

“Today is a major victory for the state of Oklahoma, the nation and everyone who has lost a loved one because of an opioid overdose,” he said. “Our evidence convincingly showed that this company did not just lie and mislead, they colluded with other companies en route to the deadliest man-made epidemic our nation has ever seen.”

Purdue Pharma is also under fire over its powerful opioid, OxyContin. Photograph: Patrick Semansky/AP

Hunter also sued Purdue Pharma, which played a leading part in kickstarting the opioid epidemic in the 1990s with its high-strength opioid, OxyContin. Purdue settled out of court for $270m before the trial but is facing hundreds of other legal actions.

Sabrina Strong, one of the trial lawyers for Johnson & Johnson, said the ruling was flawed. The company argued that the drugs it sold were approved by federal regulators and that they could not be tied directly to any deaths in Oklahoma.

“We have sympathy for all who suffer from substance abuse. But Johnson & Johnson did not cause the opioid abuse crisis here in Oklahoma or anywhere in this country,” she said.

But Balkman’s ruling looked at a bigger picture that dismissed the company’s attempt to portray the victims of the epidemic only as drug abusers.

The judge found that the opioid maker acted in concert with other companies to escalate prescriptions by pushing the false narrative that there was a desperate need for painkillers and “there was a low risk of abuse and a low danger of prescribing opioids”.

“A key element in (Johnson & Johnson’s) opioid marketing strategy to overcome barriers to liberal opioid prescribing was its promotion of the concept that chronic pain was under-treated (creating a problem) and increased opioid prescribing was the solution,” Balkman wrote.

“Among other things, they sent sales representatives into Oklahoma doctors’ offices to deliver misleading messages, they disseminated misleading pamphlets, coupons, and other printed materials for patients and doctors, and they misleadingly advertised their drugs over the internet”.

Opioid prescribing escalated for more than a decade until it reached a peak in 2012 of about 250m prescriptions, one for every American adult. About 18m opioid prescriptions were written in Oklahoma, a state of less than 4m people, in the three years to 2018.

At its height, opioid prescriptions reached 250m, one for every American adult. Photograph: Alex Wong/Getty Images

The judge said Johnson & Johnson also sought to influence medical practice with “substantial payments of money to a variety of different pain advocacy groups and organizations that influenced prescribing physicians and other health care professionals”. He said the company used academic findings “in deceptive ways” to downplay addiction risks.

Balkman also ruled that Johnson & Johnson ignored warnings from the Food and Drug Administration and its own advisory board over its marketing methods for its high strength fentanyl drug, Duragesic, and that no data existed to back up some of the claims the company was making.

The judgement said the company’s sales reps were trained to allay doctors’ concerns about addiction without requisite information on the risks.

In one company memo presented in evidence at the trial, a rep said she dismissed a doctor’s fears that patients might become addicted by telling him that those who didn’t die probably wouldn’t get hooked.

It was also revealed that Johnson & Johnson hired the consultants McKinsey, which recommended the company’s sales force should focus on doctors already prescribing large amounts of Purdue’s OxyContin. Among a list of “opportunities” to increase sales was a proposal to “target high abuse-risk patients (eg males under 40)”.