Analgesic Efficacy and Safety of Prolonged-Release Oxycodone/Naloxone in Korean Patients with Chronic Pain from Spinal Disorders

Background: A prolonged-release formulation of oxycodone/naloxone has been shown to be effective in European populations for the management of chronic moderate to severe pain. However, no clinical data exist for its use in Korean patients. The objective of this study was to assess efficacy and safety of prolonged-release oxycodone/naloxone in Korean patients for management of chronic moderate-to-severe pain. Methods: In this multicenter, single-arm, open-label, phase IV study, Korean adults with moderate-to-severe spinal disorder-related pain that was not satisfactorily controlled with weak opioids and nonsteroidal anti-inflammatory drugs received prolonged-release oral oxycodone/naloxone at a starting dose of 10/5 mg/day (maximum 80/40 mg/day) for 8 weeks. Changes in pain intensity and quality of life (QoL) were measured using a numeric rating scale (NRS, 0-10) and the Korean-language EuroQol-five dimensions questionnaire, respectively. Results: Among 209 patients assessed for efficacy, the mean NRS pain score was reduced by 25.9% between baseline and week 8 of treatment (p < 0.0001). There was also a significant improvement in QoL from baseline to week 8 (p < 0.0001). The incidence of adverse drug reactions was 27.7%, the most common being nausea, constipation, and dizziness; 77.9% of these adverse drug reactions had resolved or were resolving at the end of the study. Conclusions: Prolonged-release oxycodone/naloxone provided significant and clinically relevant reductions in pain intensity and improved QoL in Korean patients with chronic spinal disorders.