U.S. regulators rejected Thursday a tamper-resistant painkiller from Pfizer(PFE) and Pain Therapeutics(PTIE), said U.S. Food and Drug Administration spokesperson Shelly Burgess Thursday night. The Pfizer-Pain Therapeutics drug, Remoxy, is a long-acting opioid consisting of the narcotic oxycodone mixed with ingredients aimed at making it resistant to abuse and misuse. Pfizer confirmed Remoxy’s rejection in a statement issued Friday morning but would not disclose the reasons for why FDA decided against approval.