A randomized, open-label study of once-a-day AVINZA® (morphine sulfate extended-release capsules) versus twice-a-day OxyContin® (oxycodone hydrochloride controlled-release tablets) for chronic low back pain: The extension phase of the ACTION trial

Abstract

The ACTION trial, an open-label, randomized, multicenter, two-part study, compared the efficacy and safety of two sustained-release opioids (SROs), A VINZA (A-MQD), morphine sulfate extended-release capsules given once a day, and OxyContin (O-ER), oxycodone modified-release tablets given twice a day, in subjects with chronic, moderate to severe low back pain. The first part of the study, the evaluation phase, was followed by an optional four-month extension phase aimed at evaluating the long-term stability of pain control, SRO dose, and quality of sleep. Three hundred and ninety-two subjects were enrolled in the study; 220 completed the evaluation phase, and 174 entered the extensionphase. During the latterphase, subjects in the A-MQD group (n=79) continued to report lower pain scores, better quality of sleep, lower daily morphine-equivalent doses (means of 86 mg versus 119 mg), and a comparable usage of ibuprofen compared to subjects in the O-ER group (n=95). The incidence and severity of elicited opioid side effects were similar between the two groups. Both study drugs resulted in significant pain relief and improved sleep in SRO-naive patients with chronic low back pain, and this outcome was attained with a stable daily SRO dose. In patients who completed opioid dose titration, A VINZA performed significantly better than OxyContin in reducing pain scores and improving sleep-with a lower morphine-equivalent daily dose-during both the evaluation and extension phases.