Objective: To evaluate the efficacy and safety of oxycodone hydrochloride control led-release (CR) tablets (Oxycontin(R), Mundipharma International Limited, Cambridge, UK), 5 mg, 10 mg, 20 mg, and 40 mg in relieving moderate to severe non-cancer pain. Method: Two multi-center, open-label, prospective, self-controlled clinical trial, used identical protocols. All the subjects were patients with moderate to severe non-cancer pain. The clinical data were collected in the natural course of clinical treatment. Results: Treatments with oxycodone CR tablets was associated with fast onset on pain relief; 85.2% of patients in study 1 and 91.8% of patients in study 2 achieved pain relief within I hour of drug administration. Clinical efficacy: Both studies demonstrated that oxycodone CR tablets showed good clinical efficacy for relieving both moderate and severe non-cancer pain. Patients experienced sustained pain relief from the first week of treatment. Patients in both study I and study 2 experienced a dramatic pain score reduction (as assessed by VAS) after the first week of treatment. Safety profile: During oxycodone CR treatment, use of concomitant medications decreased significantly. A few patients developed ADRs in the first week, which decreased significantly as the treatment continued. Constipation was the most common ADR in the first week, which decreased to 10% of patients from the second week of treatment. Conclusion: Oxycodone CR tablets demonstrated fast onset of pain control and superior efficacy for relieving both moderate and severe non-cancer pain, as well as significant reductions in the number of concomitant medications, demonstrating a good safety profile. (C) 2007 Elsevier Science Ltd.