Opioid rotation versus combination for cancer patients with chronic uncontrolled pain: a randomized study

Background: For cancer patients with inadequate pain relief, a switch to an alternative opioid is the preferred option for symptomatic improvement. However, multiple opioids are often simultaneously administered for anecdotal reasons. This prospective study evaluated pain response to either opioid rotation or combination in patients with uncontrolled cancer pain. Methods: Patients suffering with uncontrolled cancer pain despite dose titration were randomly assigned to opioid rotation group or opioid combination group. Patients answered a questionnaire that included items on pain severity (0 to 10) and interferences at baseline and after one week. Results: Of the 50 patients registered, 39 patients answered the questionnaire after one week of treatment. After one week, the mean pain scores were significantly improved in both groups. Ten patients (42 %) in the rotation group and 16 patients (62 %) in the combination group reported that they achieved relief from pain (p = 0.08). The incidence of adverse events was similar in both groups, but fewer patients experienced constipation with opioid rotation than with combination (17 % vs. 42 %, respectively; p = 0.05). The frequency of rescue analgesics (50 % vs. 69 %; p = 0.17) and dose modification (29 % vs. 38 %; p = 0.49) were similar in the rotation and combination groups. Conclusions: For patients with chronic uncontrolled cancer pain, both opioid rotation and combination strategies appear to provide significant relief of pain and improved patient satisfaction.