Are opioids effective in the treatment of chronic low-back pain?
Overall, in patients with chronic low-back pain, opioids are moderately more effective than placebo in the short term for pain relief and slightly more effective in the short term for improving function. However, data for long term use are pretty much nonexistent. The long-term use of opioids for patients with chronic low-back pain is controversial. Physicians are asked to provide comfort to patients, yet the regulatory and safety concerns of long-term use are a sobering counterpoint. (LOE = 1a-)
Chaparro LE, Furlan AD, Deshpande A, Mailis-Gagnon A, Atlas S, Turk DC. Opioids compared with placebo or other treatments for chronic low back pain: an update of the Cochrane review. Spine 2014;39(7):556-563.
|Study Design: Meta-analysis (randomized controlled trials)||Funding: Self-funded or unfunded|
|Setting: Various (meta-analysis)||Allocation: Unknown|
This is an update to a Cochrane Review published in 2007. The authors systematically searched several databases to identify randomized trials comparing opioids with placebo or other drugs. The studies had to have masked outcome assessments and evaluated at least one of the following: pain, function, global improvement, or the proportion of patients reporting 30% or 50% pain relief. Two authors independently assessed studies for inclusion, reconciling disagreements by discussion. Additionally, 3 authors independently extracted data from included studies. Finally, they used an explicit approach to assess the quality of each study and to assess the role of publication bias. Eventually, these authors included 15 trials with 5540 participants. For the most part, the reviewed trials had low to moderate quality, high drop-out rates, short duration, and limited interpretability of functional improvement. Six studies evaluated tramadol alone or in combination with acetaminophen (5 compared with placebo, 1 as an active comparator against a centrally acting nonopioid); 2 studies compared buprenorphine with placebo; and 7 studies assessed strong opioids (morphine, oxymorphone, hydromorphone, oxycodone). Of the 7 trials of strong opioids, 3 were not really designed to assess opioid efficacy. Twelve of the 15 total studies were at low risk of bias. The 5 studies comparing tramadol with placebo generally had more methodologic bias and showed greater overall pain relief than placebo and greater improvement in functional outcomes than placebo. In the 2 studies of buprenorphine, the authors found very-low-quality evidence that this agent reduces pain more than placebo and that it does anything for function. The studies of strong opioids found small reductions in pain and small improvements in function.
Henry C. Barry, MD, MS
Michigan State University
East Lansing, MI