For the study, a team of Canadian researchers evaluated 30 patients with chronic low back pain of more than six months duration.
In the double-blinded, random-ordered, placebo-controlled trial, subjects performed a lifting test twice, once after receiving intravenous fentanyl and once after taking a placebo.
The objective of the study was to examine the impact of acute opioid administration on repetitive lifting and lowering exercise in workers with low-back pain.
The study showed that opioids improved lifting performance between 15 and 48 percent.
The researchers concluded that the performance improvement was due to reduced pain intensity.
Pain reduction, as measured by pain scales, was indicative of clinically relevant analgesia achieved by the medication.
However, the researchers suggest that longer trials are needed to measure the effectiveness of opioids as an adjunct to functional restoration programs for workers with low-back pain.
The study is published in The Journal of Pain, the peer review publication of the American Pain Society.