Objectives: To investigate the efficacy and safety of antidepressants in patients with back pain and osteoarthritis compared to placebo.
Methods: Systematic review with meta-analysis. We searched electronic databases and trial registries from their inception to May 12, 2020 for randomised trials investigating the efficacy of any antidepressant drug to placebo in participants with low back and neck pain, sciatica or hip and/or knee osteoarthritis. Pain (0-100) and disability (0-100) were primary outcomes. We assessed risk of bias with the Cochrane Collaboration’s tool and certainty of evidence with the GRADE framework. We calculated mean differences (MD) and 95% confidence intervals (CI) using a random effects model.
Results: We included 33 trials (n=5,110 participants). Moderate certainty evidence showed that serotonin–norepinephrine reuptake inhibitors (SNRI) reduce pain at the 3-13 weeks follow-up for participants with back pain (MD -5.3, 95% CI -7.31 to -3.30) and osteoarthritis (MD -9.7, 95% CI -12.75 to -6.69). Very low certainty evidence showed that SNRI antidepressants reduced sciatica pain at the ≤2 weeks (MD -18.6, 95% CI -31.87 to -5.33), but not in the 3-13 weeks follow-up. Low to very low certainty evidence showed that tricyclic antidepressants (TCA) did not reduce sciatica pain at the ≤2 weeks follow-up (MD -7.6, 95% CI -18.25 to 3.15), but did so in the 3-13 weeks and 3-12 months follow-ups. TCA and other antidepressants did not reduce pain or disability for back pain.
Conclusion: There is moderate certainty evidence that the effect of SNRI antidepressants on pain and disability scores is small and not clinically important for back pain, but a clinically important effect cannot be excluded for osteoarthritis. TCA and SNRI antidepressants may be effective for sciatica, but the certainty of evidence ranged from low to very low.