Background
Chronic pain is common and debilitating, impacting approximately one in five people globally. Musculoskeletal conditions like back pain are generally the most common conditions leading to chronic pain, followed by headache, visceral pain, and orofacial pain. Chronic pain can be difficult to treat and management is frequently suboptimal. Non-steroidal anti-inflammatory drugs may provide small benefits for pain reduction in some situations, but they need to be used with caution and for short periods because of the risk of serious adverse events. Antidepressants are often used in the treatment of chronic pain.
Objective
To provide a comprehensive summary of the efficacy, safety, and tolerability of antidepressants for pain according to condition.
Methods
- This review was prospectively registered and followed guidelines from the preferred reporting items for overviews of reviews (PRIOR) statements.
- We included systematic reviews with or without meta-analysis that examined the efficacy of any antidepressant drug compared with a placebo used for any pain conditions in adults.
- Two reviewers independently extracted data.
- The main outcome was pain; for headache diseases, it was the frequency of headaches.
- Continuous pain outcomes were converted into a scale of 0 (no pain) to 100 (worst pain) and were presented as mean differences (95% confidence intervals).
- Data were extracted from the time point closest to the end of the treatment.
- When the end of the treatment was too variable across trials in a review, data were extracted from the outcome or time point with the biggest number of trials and participants.
- The secondary outcomes were safety and tolerability.
- Findings were categorized from each comparison as efficacious, inconclusive, or not efficacious.
- Certainty of evidence was evaluated with the grading of recommendations assessment, development, and evaluation framework.
Results
- 26 reviews (156 unique and >25,000 participants) were included.
- These reviews reported on the efficacy of eight antidepressant classes covering 22 pain conditions.
- No review delivered high-certainty evidence on the efficacy of antidepressants for pain for any condition.
- 11 comparisons (nine conditions) were found where antidepressants were effectual, and four with moderate certainty evidence: serotonin-norepinephrine reuptake inhibitors (SNRIs) for back pain, postoperative pain, fibromyalgia, and neuropathic pain.
Conclusion
Evidence of the efficacy of antidepressants was found in 11 of the 42 comparisons included in this overview of systematic reviews- 7 of the 11 comparisons examined the efficacy of SNRIs. For the other 31 comparisons, antidepressants were either not effectual or the evidence was inconclusive. The results indicate that a more nuanced approach is required when prescribing antidepressants for pain conditions.