Efficacy and safety of sustained-release oxycodone compared with immediate-release morphine for pain titration in cancer patients: A multicenter, open-label, randomized controlled trial (SOCIAL).

Background: The study aims to investigate the effect and safety of sustained-release oxycodone hydrochloride as background dose on pain titration in patients with moderate-to-severe cancer pain. Material and methods: Adult patients scheduled with a regular strong opioid for cancer-related pain were recruited and randomly assigned to sustained-release oxycodone group (tablets, 12 hourly) and immediate-release morphine group (5mg initially, hourly). All patients were hourly reassessed for efficacy and dose titration. Results: The primary end point was the number of titration cycles required to achieve adequate pain relief (numerical rating scale, NRS <= 3). Secondary end points included the proportion of patients achieving adequate pain relief during each cycle, potential predictive factors for titration performance, and side effects. Ninety (94.7%) patients in oxycodone group and 78 (86.7%) patients in morphine group achieved adequate pain control during 1 to 4 cycles of titration. Patients in oxycodone group reached adequate pain control within the first 2 cycles of titration, which was significantly shorter than morphine group wherein the number of titration cycles ranged from 1 to 4 (P=.034). Oxycodone prescription significantly increased the response rate of patients to morphine titration during the first cycle of titration (P=.010). The initial NRS score and oxycodone administration were significantly associated with titration performance. The mild or moderate adverse effects were similar in 2 groups, while severe adverse effects were only identified in morphine group (P=.001). Conclusion: Use of background sustained-release oxycodone is more efficient and better tolerated on dose titration than immediate-release morphine.