Affiliation:
1. Faculty of Medicine and Health School of Public Health University of Sydney Sydney New South Wales Australia
2. Sydney Musculoskeletal Health University of Sydney and Sydney Local Health District Sydney Australia
3. College of Health Medicine, and Wellbeing University of Newcastle Newcastle New South Wales Australia
4. University of Washington School of Medicine Seattle Washington USA
5. Warwick Clinical Trials Unit University of Warwick Coventry United Kingdom
6. University Hospitals of Coventry and Warwickshire Coventry United Kingdom
7. Faculty of Medicine and Health Sydney Pharmacy School University of Sydney Sydney New South Wales Australia
8. Cancer Therapy Centre Liverpool Hospital Liverpool New South Wales Australia
9. South Western Clinical School University of New South Wales Sydney New South Wales Australia
Abstract
AbstractPain is one of the most burdensome symptoms in people with cancer, and opioid analgesics are considered the mainstay of cancer pain management. For this review, the authors evaluated the efficacy and toxicities of opioid analgesics compared with placebo, other opioids, nonopioid analgesics, and nonpharmacologic treatments for background cancer pain (continuous and relatively constant pain present at rest), and breakthrough cancer pain (transient exacerbation of pain despite stable and adequately controlled background pain). They found a paucity of placebo‐controlled trials for background cancer pain, although tapentadol or codeine may be more efficacious than placebo (moderate‐certainty to low‐certainty evidence). Nonsteroidal anti‐inflammatory drugs including aspirin, piroxicam, diclofenac, ketorolac, and the antidepressant medicine imipramine, may be at least as efficacious as opioids for moderate‐to‐severe background cancer pain. For breakthrough cancer pain, oral transmucosal, buccal, sublingual, or intranasal fentanyl preparations were identified as more efficacious than placebo but were more commonly associated with toxicities, including constipation and nausea. Despite being recommended worldwide for the treatment of cancer pain, morphine was generally not superior to other opioids, nor did it have a more favorable toxicity profile. The interpretation of study results, however, was complicated by the heterogeneity in the study populations evaluated. Given the limited quality and quantity of research, there is a need to reappraise the clinical utility of opioids in people with cancer pain, particularly those who are not at the end of life, and to further explore the effects of opioids on immune system function and quality of life in these individuals.