Fentanyl skin patches achieve better pain relief and an enhanced quality of life than sustained release oral morphine, say patients with chronic non-cancer pain in a study in the British Medical Journal.
Patients with chronic non-cancer pain, requiring continuous treatment with potent opioids, were randomly assigned to two groups to assess their treatment preference, pain control, and quality of life. One group received four weeks of treatment with sustained release oral morphine followed by fentanyl patches for four weeks. The second group received the same treatments but in reverse order.
Of 212 patients, 138 (65%) preferred fentanyl patches, whereas 59 (28%) preferred sustained release oral morphine and 15 (7%) expressed no preference. The main reason given for preferring fentanyl was better pain relief, followed by greater convenience and fewer adverse events.
Patients receiving fentanyl also had higher overall quality of life scores than patients receiving morphine. Although the level of adverse events was similar in both treatment groups, more patients experienced constipation with morphine than with fentanyl. These findings confirm that potent opioids can provide satisfactory pain relief for the difficult clinical problem of chronic non-cancer pain, conclude the authors.
In an accompanying editorial, pain specialist Henry McQuay acknowledges that this is a welcome trial in a difficult area, but writes: “Unfortunately the design of the trial means that we have to question the results. Rule one of drug trials that compare different formulations and use subjective outcomes such as patient preference is that the comparison should be done double blind.”
However, the authors argue for simple clinical trials based in clinical practice, using outcomes of greater relevance to patients. The ethics of perfect design with placebos and blinding is questionable, especially when such complex trials fail to recruit patients or yield useful results. Treatment options for these patients are limited. As such, this comparative trial may herald a new approach for their care and in ethical clinical trial design.