But amid the marketing blitz, concerns about addiction in patients appear to have faded from the medical profession.
The FDA, which must approve drug labels, allowed Purdue to say on its label: “The development of addiction to opioid analgesics in properly managed patients with pain has been reported to be rare.”
The agency warned that drug abusers and addicts might try to obtain the drugs, but it indicated that the risks seemed minor for patients: “We do not know how often patients with continuing (chronic) pain become addicted to narcotics, but the risk has been reported to be small.”
The agency, however, would later change its mind.
By 2008, the claims that the risks of addiction in patients were small were removed from the OxyContin label, after “extensive negotiations” with Purdue, an FDA spokeswoman said.
“The labeling information, including language regarding addiction, has evolved over time as data has become available,”Morgan Liscinsky said.
The FDA did not say what evidence led the agency to allow the previous claims or what new findings led it to ask for the removal of those claims.
Early on, however, the agency relied on industry experts for advice. In the 2002 FDA meeting, for example, eight of the 10 invited experts had connectionswith pharmaceutical companies. Of those, five had served as speakers, consultants or investigators for Purdue, including Portenoy and Kathy Foley, a neuro-oncologist at Memorial Sloan Kettering Cancer Center. Together, Portenoy and Foley had published a key study on opioids in 1986 that found that only two of 38 patients seemed to abuse the drugs and that both had histories of substance abuse.
“Their past work with industry should not preclude them from sharing their expertise with government agencies or their peers in the medical community,” Heins, the Purdue spokesman, said.
The FDA and doctors also could turn to a spate of other trials that seemed to suggest there was little reason to worry that chronic pain patients could get addicted to opioids.
Take, for example, a 2003 report in the New England Journal of Medicine, which reviewed the conclusions from several studies.
“The general finding is that patients with chronic pain . . . can achieve satisfactory analgesia . . . with a minimal risk of addiction,” it said, while questioning the use of high doses.
What may be most striking about the paper, though, is that its lead author has become one of the top critics of opioid prescribing habits. But Jane Ballantyne, a pain specialist at the University of Washington, said that at the time there were very few clinical trials that showed any sign of an addiction risk.