in 1996, purdue pharma "began a massive marketing campaign", based on a "unique claim" for oxycontin, with fda permission, that, "as a long-acting opioid, it might be less likely to cause abuse and addiction than shorter-acting painkillers like percocet." by 1998, purdue's audiotapes, brochures, videotapes, literature and its website "partners against pain", "claimed that the risk of addiction from oxycontin was extremely small."