> They were touted as not being addictive in the same way as opium
Oxycotin was never touted as "not being addictive".
Hell they had (and still have) a big "WARNING: OxyContin is an opioid agonist and a Schedule II controlled substance with an abuse liability similar to morphine." in their label.
It was a confluence of medical professionals being taught "pain is the 5th vital sign", "pain is routinely undertreated" and "controlled release opioids have a reduced abuse potential".
This was not necessarily bad because many of those things were true and the pendulum had swung back from "just tough it out", "Tylenol is enough for most people", "just one dose of opioids will make you an addict".
Then layer on top pill mill clinics popping up where doctors were dispensing scripts for 120 sixty milligram Oxycotin without so much as a physical examination, the DEA doing nothing despite having ample data in front of them that some doctors were dispensing milions of pills each year and the massive amounts of money doctors made writing the scripts by charging addicts cash.