Treatment of persistent pain associated with osteoarthritis with controlled-release oxycodone tablets in a randomized controlled clinical trial.

Objective: This study, lasting up to 90 days, was undertaken in patients with osteoarthritis with persistent moderate to severe pain uncontrolled by standard therapy (nonsteroidal anti-inflammatory drugs, acetaminophen, and/or short-acting opioids) to evaluate functional outcomes, as well as efficacy and safety, of controlled-release oxycodone versus placebo. Methods: One hundred seven patients received either controlled-release oxycodone or placebo every 12 hours in this double blind, randomized, placebo-controlled, parallel-group study. Stable previous regimens of acetaminophen or nonsteroidal anti-inflammatory agents were allowed to continue. Primary efficacy variables included Brief Pain Inventory average pain intensity scores at completion of initial titration, Western Ontario and McMaster Universities Osteoarthritis Index scores at days 30 and 60, and the percentage of patients discontinuing due to inadequate pain control. Results: Controlled-release oxycodone was significantly superior to placebo in decreasing average pain intensity and in reducing pain-induced interference with general activity, walking ability (except at day 30), and normal work, as well as mood, sleep, relations with people (at days 60 and 90), and enjoyment in life. Daily functioning, as measured by the Western Ontario and McMaster Universities Osteoarthritis Index, was also significantly improved in the controlled-release oxycodone group. In the placebo group, a significantly greater percentage of patients discontinued due to inadequate pain control. Adverse events were consistent with opioid adverse events, and no safety concerns were noted. Discussion: Treatment with controlled-release oxycodone of patients with osteoarthritis with persistent moderate to severe pain uncontrolled by standard therapy resulted in significant pain control and improvements in physical functioning.