Clinical Question: Are antidepressants effective in the management of chronic low back pain?
Setting: Various (meta-analysis)
Study Design: Systematic review
Synopsis: The authors systematically reviewed several databases looking for randomized placebo-controlled trials of oral antidepressants in managing chronic low back pain. Studies designed to assess the treatment of multiple medical conditions were included if sufficient data were available to assess treatment effect on the subset of patients with back pain. Non–English-language publications were included in the review. Two reviewers extracted the data, but the way in which discrepancies were resolved or the degree of agreement between the reviewers was not reported. Additionally, they developed a 22-point methodologic quality-rating scale based on criteria from the Cochrane Collaboration Back Review Group and guidelines from the former Agency for Health Care Policy and Research (now the Agency for Healthcare Research and Quality). Disagreements on the assignment of quality were resolved through consensus.
The authors identified 22 trials, but excluded 15 of them. Nine trials lacked a placebo, three used parenteral antidepressants, two included neck and back pain without sufficient detail to extract the data on back pain, and one was reported so poorly that no baseline pain data and no denominator data were available.
The seven remaining trials included only patients with chronic low back pain. One was a placebo-controlled study of two antidepressants. The methodologic quality scores ranged from 11 to 19. Norepinephrine-reuptake inhibitors (i.e., amitriptyline, nortriptyline, maprotiline, imipramine) were evaluated in five trials. Using different assessment techniques, the results of four trials showed decreases in pain, although the decreases may not have been clinically important. Only one study showed any effect on function. The studies using antidepressants that do not inhibit norepinephrine reuptake (i.e., paroxetine, trazodone) had negligible effects on pain or functional status.
Bottom Line: Tricyclic and tetracyclic antidepressants that inhibit norepinephrine reuptake appear to produce moderate reductions in symptoms among patients with chronic low back pain. Selective serotonin reuptake inhibitors do not appear to benefit patients with chronic low back pain. None of the antidepressants appeared to have much effect on functional status. (Level of Evidence: 1a)