Advertisement

12/11/2003 By Jill Taylor

Antidepressants that inhibit norepinephrine reuptake (tricyclics and tetracyclics) may be mildly to moderately effective in reducing chronic low back pain, according to a new study.

Tricyclic antidepressants have been demonstrated to decrease pain associated with diabetic neuropathy, postherpetic neuralgia, as well as provide benefit in cases of fibromyalgia, migraines, and idiopathic pain.

Additionally, antidepressants are sometimes prescribed for analgesic purposes in patients with back pain. However, previous reviews have reached conflicting conclusions regarding the efficacy of antidepressants for treatment of back pain.

To assess efficacy of antidepressants for the treatment back pain and determine whether outcomes vary between antidepressant classes, Thomas O. Staiger, MD, and colleagues of the University of Washington, Seattle, United States performed a systematic literature review of randomised, placebo-controlled trials of oral antidepressive agents in patients with back pain.

Studies were identified through internet search of MEDLINE, PsycINFO, and the Cochrane Controlled Trials Registry. Independent reviewers extracted data, and assessed studies using a 22-point methodologic quality assessment scale based on the 19-point criteria list developed by the Cochrane Collaboration Back Review Group.

The reviewers identified 22 trials of antidepressants for the treatment of back pain, of which 7 studies of chronic low back pain met inclusion criteria. No adequate studies on the use of antidepressants for acute back pain were found.

Among studies using antidepressants that inhibit norepinephrine reuptake (tricyclic or tetracyclic antidepressants), 4 of 5 found significant improvement in at least 1 relevant outcome measure. Furthermore, evidence suggests that the effect of these antidepressants in chronic low back pain is independent of patient depression status.

Conversely, no analgesic benefit was observed in studies of antidepressants that do not inhibit norepinephrine reuptake (paroxetine and trazodone).

The impact of tricyclic medications on functional status in patients with low back pain was unclear. Among 4 studies of tricyclic antidepressants that included a functional measure, 1 found significant improvement, 1 found borderline significant improvements, and 2 found no significant improvement.

"More research could better-define the benefits and risks of antidepressants in the treatment of patients with chronic low back pain and whether antidepressants can improve the functional status of these patients," conclude the researchers.

Spine 2003 Nov 15;28:22:2540-5. "Systematic review of antidepressants in the treatment of chronic low back pain"