Randomized, double-blind, cross-over trial comparing safety and efficacy of oral controlled-release oxycodone with controlled-release morphine in patients with cancer pain

Abstract

Purpose: Use of oxycodone for chronic cancer pain has been hampered by its short elimination half-life. This study was designed to compare the efficacy and safety of controlled-release formulations of oxycodone and morphine for cancer pain.

Patients and methods: Thirty-two adult patients with cancer pain and a > or = 3-day history of stable analgesia with oral opioids provided written informed consent and were randomized to controlled-release oxycodone or controlled-release morphine for 7 days. To blind the study using available tablet strengths, the dose ratio of oxycodone to morphine was set at 1:1.5. On day 8, patients were crossed over to the alternate drug for 7 days. Pain intensity was assessed using a visual analog scale (VAS 0 to 100 mm) and a categorical scale (CAT 0 to 4). Side effects were assessed using a checklist (four-point categorical severity) and a nondirected questionnaire. Patients and investigators made blinded global ratings of efficacy and treatment preference.

Results: Twenty-three patients completed the study (10 men, 13 women). The VAS and CAT scores were (mean+/-SD) 23+/-21 and 1.2+/-0.8 on controlled-release oxycodone, and 24+/-20 (P=.43) and 1.3+/-0.7 (P=.36) on controlled-release morphine. No period or carryover effect was detected. There were no significant differences in adverse effects (P=.40) or ratings of efficacy and preference. The median oxycodone/morphine dose ratio was 1.5 and the maximum was 2.3.

Conclusion: Controlled-release oxycodone is as safe and effective as controlled-release morphine in the treatment of cancer pain.