A randomized, open-label, multicenter trial comparing once-a-day AVINZA® (morphine sulfate extended-release capsules) versus twice-a-day OxyContin® (oxycodone hydrochloride controlled-release tablets) for the treatment of chronic, moderate to severe low back pain: Improved physical functioning in the ACTION trial

Abstract

This multicenter trial compared the efficacy, safety, and effect on quality of life and work limitation of once-daily extended-release morphine sulfate capsules (AVINZA9, A-MQD) and twice-daily controlled-release oxycodone HCl tablets (OxyContin9, O-ER) in subjects with chronic, moderate to severe low back pain. After randomization and a period of opioid dose titration, subjects (n = 266) underwent an eight-week evaluation phase and an optional four-month extension phase (n = 174 in extension phase). Subjects were assessed using the 12-item Short-Form Health Survey9 (SF-12) and the Work Limitations Questionnaire9 (WLQ). In both groups, significant improvements were observed in the SF-12 mean scores for physical functioning (p < 0.001), role physical (p < 0.0001), bodily pain (p < 0.0001), physical summary (p < 0.001), and mental component summary (p < 0.005). At the end of the titration period, greater relative improvements from baseline were seen in the SF-12 section on physical components in the A-MQD group versus the O-ER group, with significant differences observed for physical functioning (p = 0.0374), role physical (p = 0.0341), bodily pain (p = 0.0001), and physical summary (p = 0.0022). In both groups, SF-12 mean scores improved significantly for mental health (p < 0.01), role emotional (p < 0.01), social functioning (p < 0.0005), vitality (p < 0.005), and the mental component summary (p < 0.005), but no significant differences were noted between the two groups. Both groups reported improvement from baseline in WLQ physical demands scores, with no significant differences noted between the two groups. At the end of the evaluation phase, fewer subjects were unable to work due to illness or treatment in the A-MQD group than in the OER group (8.5percent versus 19.4percent, respectively; p = 0.0149). In conclusion, compared to twice-daily OxyContin, once-daily AVINZA resulted in significantly better and earlier improvement of physical function and ability to work.