Efficacy and safety of controlled-release versus immediate-release oxycodone: randomized, double-blind evaluation in patients with chronic back pain.

Objective: To compare the efficacy and safety of controlled-release oxycodone given every 12 hours with immediate-release oxycodone given four times daily in patients with persistent back pain.

Design: Randomized, double-blind, active-controlled, two-period crossover trial.

Patients: Fifty-seven adult outpatients with stable, chronic, moderate-to-severe low back pain despite analgesic therapy were enrolled; 47 were randomized; 11 discontinued for side effects, most commonly nausea and vomiting.

Interventions: Controlled-release oxycodone tablets given every 12 hours; immediate-release oxycodone tablets given four times daily; dose titration with controlled-release or immediate-release for up to 10 days; double-blind treatment for 4-7 days each.

Outcome Measures: Patients' pain scores (0 = none, 1 = slight, 2 = moderate, 3 = severe).

Results: Pain intensity decreased from moderate to severe at baseline to slight at the end of titration with both oxycodone formulations. The daily oxycodone dose was 40 mg or less in 68% of patients. During double-blind treatment, mean pain intensity was maintained at 1.2 (0.1 SE) with controlled-release and at 1.1 (0.1 SE) with immediate-release oxycodone. The most common adverse events were constipation, nausea, pruritus, somnolence, and dizziness.

Conclusions: Controlled-release oxycodone given every 12 hours was comparable with immediate-release oxycodone given four times daily in efficacy and safety, and it provides convenient, twice-daily, around-the-clock treatment for selected patients with persistent back pain that is inadequately controlled by nonopioids or as-needed opioid therapy.