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 virtually 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. (Level of Evidence = 1a–)
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, three 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 5,540 participants. For the most part, the reviewed trials had low to moderate quality, high dropout rates, short duration, and limited interpretability of functional improvement.
Six studies evaluated tramadol (Ultram) alone or in combination with acetaminophen (five compared with placebo, one as an active comparator against a centrally acting nonopioid); two studies compared buprenorphine with placebo; and seven studies assessed strong opioids (morphine, oxymorphone, hydromorphone [Dilaudid], oxycodone [Oxycontin]). Of the seven trials of strong opioids, three were not designed to assess opioid effectiveness. Twelve of the 15 total studies were at low risk of bias. The five 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 two studies of buprenorphine, the authors found very low-quality evidence that this agent reduces pain more than placebo and that it improves function. The studies of strong opioids found small reductions in pain and small improvements in function.
Study design: Meta-analysis (randomized controlled trials)
Funding source: Self-funded or unfunded
Setting: Various (meta-analysis)
Reference: ChaparroLEFurlanADDeshpandeAMailis-GagnonAAtlasSTurkDCOpioids compared with placebo or other treatments for chronic low back pain: an update of the Cochrane review. Spine (Phila Pa 1976).2014; 39( 7): 556– 563.