New Study: Opioids Not the Best Choice for Alleviating Chronic Noncancer Pain

By Lynn Hetzler via Multibriefs

Opioids are invaluable for treating chronic cancer pain, post-surgical pain and severe acute pain, but the results of a new study suggest that opioids may not be as good at reducing chronic noncancer pain.

With the rise of the opioid epidemic, using opioids to treat chronic pain is now under scrutiny. The dangers of opioid overprescribing are increasingly evident, as is the need to gain greater understanding of when opioids are likely to be effective.

In short, research found that opioids provided small improvements in pain, sleep quality and physical functioning compared to a placebo, but the differences between the two pain relievers did not meet minimally important difference standards and there are no differences between opioids and placebo in social, emotional or role functioning. A minimally important difference (MID) is the smallest change in treatment that an individual patient would say is significant enough to change treatment.

Most importantly, opioids did not reduce pain or improve physical functioning any better than did nonsteroidal anti-inflammatory drugs (NSAIDs) or tricyclic antidepressants. Furthermore, opioids were associated with a higher rate of vomiting and other side effects.

The results of the study suggest that opioids provide minimal benefit for chronic pain and that the pain-relieving benefits likely diminish with prescription length. Opioids do not outperform safer options for alleviating noncancer chronic pain.

A Systematic Review and Meta-analysis of Opioids for Noncancer Chronic Pain

Researchers performed a systematic review and meta-analysis of 96 trials that included a total of 26,169 patients with chronic noncancer pain. The median age was 58 years, and 61 percent of participants were female. The participants were randomly assigned to opioid versus nonopioid control and followed for four weeks or longer.

The team used Visual Analog Scales (VAS) to quantify pain intensity and sleep quality, and used the 36-item short form survey (SF-36) to assess physical, emotional and social functioning. Specifically, they converted pain intensity to the 10 cm VAS for pain, sleep quality to the 100 mm VAS for sleep, and physical, emotional, and social functioning to the 100-point SF-36. Participants started with a mean pain score of 6.54 cm on the VAS.

The researchers found that, while opioids improved pain, physical functioning and sleep quality, they did not reach MID. Moreover, studies with longer follow-ups showed that opioids provided less pain relief.

The scientists found no statistical differences for emotional, social or role functioning between the opioid group and the placebo groups. There were no statistical differences in pain improvement with opioids compared with NSAIDs and tricyclic antidepressants, although opioids did make a small difference as compared to anticonvulsants.

The study was limited in that it was restricted to patients who did not have co-morbid substance abuse or other mental health issues, so the results may not reflect the outcome in the general population. Furthermore, the longest follow-up of the surveyed studies was only six months, so the effects of long-term opioid use for chronic pain remain to be seen.

While all the trials included in the study were at risk for bias, 51 percent had adequate randomization, half had appropriately concealed allocation, and more than 85 percent were blinded study participants and clinicians.

Jason W. Busse, DC, Ph.D., led the study. The researchers published their results in JAMA.

Lynn Hetzler has been a freelance writer for more than 15 years. She has extensive experience in a variety of specialties, including transplantation, oncology, fertility, negligible senescence, laboratory science, addiction, general research and more. Lynn specializes in creating informative and engaging medical content for readers of all levels, from patients to researchers and everyone in between.