Overview A Comparison of the Addiction Liability of Hydrocodone and Sustained Release Morphine Status: Completed Trial end date: 2008-04-01 Target enrollment: Participant gender: Summary Characterize the relative abuse liability of a short versus a long acting opioid in chronic pain patients. Phase: Phase 4 Details Lead Sponsor: University of California, DavisTreatments: AcetaminophenAmphetamineHydrocodoneMorphinePhenobarbital