The opioid epidemic in the United States has claimed many victims, and a major pharmaceutical company was told Monday that it will be paying a hefty price for its involvement.

An Oklahoma judge determined that Johnson & Johnson was liable for fueling an opioid epidemic in the south central US state by deceptively marketing addictive painkillers and ordered the New Jersey-based drugmaker to pay $572.1 million.

Opioids were involved in almost 400,000 overdose deaths from 1999 to 2017, according to the US Centers for Disease Control and Prevention.

Since 2000, some 6,000 Oklahomans have died from opioid overdoses, according to the state's lawyers.

The trial came about after Oklahoma had resolved claims against OxyContin maker Purdue Pharma LP in March for $270 million and against Teva in May for $85 million, leaving J&J as the lone defendant.

Lawyers for Oklahoma argued that J&J— the first opioid maker to face trial — carried out a years-long marketing campaign that minimized the painkillers' addiction risks and promoted their benefits.

The state's witnesses cited statistics showing that enough opioids were dispensed in 2017 for every adult in Oklahoma to be given the equivalent of 156 hydrocodone 10 milligram tablets, according to The Oklahoman website.

Still, the award was well below what some investors and analysts feared, in what had been a $17 billion lawsuit viewed as a bellwether for other litigation nationwide over the opioid crisis.

"The expectation was this was going to be a $1.5 billion to $2 billion fine," said Jared Holz, healthcare strategist for Jefferies, adding that the $572 million "is a much lower number than had been feared".

As a result, J&J shares rose in after-hours trading.

J&J, the No. 37 company in the Fortune 500, said it would appeal to the Oklahoma Supreme Court and will look to put the award payment on hold.

"Janssen (a subsidiary of J&J) did not cause the opioid crisis in Oklahoma, and neither the facts nor the law support this outcome," Michael Ullmann, J&J's general counsel, said in a statement.

The decision by Judge Thad Balkman of Cleveland County District Court in Norman, Oklahoma, followed a seven-week non-jury trial.

The case brought by Oklahoma Attorney General Mike Hunter was the first to go to trial out of thousands of lawsuits filed by state and local governments against opioid manufacturers and distributors.

Oklahoma argued that J&J's marketing practices helped fuel the opioid epidemic by flooding the market with painkillers.

"Johnson & Johnson will finally be held accountable for thousands of deaths and addictions caused by their actions," Hunter said.

The attorney general has said that between 2015 and 2018, 18 million opioid prescriptions were written in Oklahoma, a state with around 4 million people.

Hunter said J&J "embarked on a cynical, deceitful, multibillion-dollar brainwashing campaign to establish opioid analgesics as the magic drug."

J&J has denied wrongdoing, saying its marketing claims had scientific support and that its painkillers, Duragesic and Nucynta, accounted for a small fraction of opioids prescribed in Oklahoma.

Ullmann faulted Oklahoma for attempting a "misapplication of public nuisance law" that judges in other states had already rejected.

Oklahoma sued J&J to help it address the epidemic for the next 30 years through treatment and prevention programs.

But the judge said the figure he awarded covered only one year, saying Oklahoma did not offer enough evidence of the time and costs to address the opioid crisis beyond that.

The litigation has been closely watched by plaintiffs in about 2,000 opioid lawsuits pending before a federal judge in Ohio.

Reuters contributed to this story.