An investigative journalist looking into how Purdue Pharmaceutical marketed prescription drugs told Fox Nation's "Tucker Carlson Today." that some patients were told their addiction-like side effects from OxyContin and feelings were actually, though falsely, pseudoaddiction.

Gerald Posner told host Tucker Carlson in a new episode called, ‘Fueling an Epidemic’ that not only did OxyContin users experience addictive side effects, but that they also often moved on to harder, illegal drugs to get their fix without having to fill a prescription.

"If a doctor went to them and said, 'by the way, I think you say the odds of addiction are very low and you can't get addicted if you're giving it just for pain -- but some of my patients seem as though they… behave like they're addicts,'" he said. "'They want more and more. They're calling me in the middle of the night. They're hitting on the door. They had a thing called pseudoaddiction…'"

"They [pharma] would say, 'no, no, no. That's not really addiction,'" he continued. "'It looks like addiction. It has all the behavior characteristics of addiction --- but you're not giving them enough OxyContin. To cure that, you need to give them more OxyContin.'"

Posner said that, in turn, Purdue would make more money because the strength of the dose was more concentrated and therefore contained more product.

OXYCONTIN MAKER PURDUE PHARMA PLEADS GUILTY IN CRIMINAL CASE 

He added that the main ingredient in the drug is very cheap to manufacture, but that the company made large sums off the pharmaceutical.

"The ingredient inside oxycodone is pennies to make. But if somebody took, let's say, a 20-milligram tablet twice a week, Purdue would make like $40. That was their profit. If they took an 80-milligram tablet, Purdue would make $600," he said.

"So they liked doctors giving ever-stronger prescriptions. They marketed it that way all the time. And [so] the side effects began."

Posner also told Carlson about the nefarious "gateway" characteristic of OxyContin:

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"People became OxyContin users. Then they often they left OxyContin to move to street drugs like heroin or fentanyl, especially heroin because it was cheaper," he said.

"It was cheaper than filling the pills for 80-milligram pills every time. And so they would actually move to street drugs. It was like-- you wanted the perfect gateway drug, they used to talk about how cannabis leads you to hard drugs," he continued. "OxyContin could lead you to heroin. It was the chemical equivalent of heroin in terms of OxyContin."

Last year, Purdue Pharma pleaded guilty to three criminal charges relating to their acknowledgement of responsibility for their part in the opioid epidemic that has contributed to hundreds of thousands of deaths.

Before a Newark, N.J. federal judge, the OxyContin-maker admitted impeding the U.S. Drug Enforcement Administration’s efforts to combat the addiction crisis.

Purdue acknowledged that it had not maintained an effective program to prevent prescription drugs from being diverted to the black market - even though it had told the DEA it did have such a program - and that it provided misleading information to the agency as a way to boost company manufacturing quotas.

The Associated Press contributed to this report.

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