How effective are opioid medications for cancer pain?

Researchers examining the data on opioids for pain caused by cancer have found surprisingly large gaps in evidence regarding the true benefits of these medicines for cancer pain. The review challenges the commonly held view that opioids are the most powerful pain relievers.

The University of Sydney-led review highlights there is no ‘one size fits all’ treatment approach for cancer pain, urging health professionals and patients to carefully weigh up the evidence when deciding on a suitable pain management plan.

However, the study found very few trials have compared commonly used opioid medicines such as morphine, oxycodone and methadone with placebo.

The study did not find convincing evidence that morphine was better or safer than other opioid medicines for background cancer pain outside of end-of-life care.

This is despite morphine being widely viewed as the ‘gold standard treatment’ for cancer care by physicians and recommended in many international clinical guidelines for moderate to severe cancer pain because of its low cost and accessibility.

The review also found non-steroidal anti-inflammatory drugs (NSAIDs) including aspirin and diclofenac may be at least as effective as some opioids for background cancer pain.

Reference: How effective are opioid medications for cancer pain?; CA A Cancer Journal for Clinicians, DOI:10.3322/caac.21823