- The benefits of mirtazapine (Remeron) for fibromyalgia do not outweigh the harms, according to the findings of this Cochrane review.
- A small subset of patients might experience benefit without adverse events.
Why this matters
- Fibromyalgia remains elusive in terms of pathophysiology and treatment.
- Some studies have hinted at a benefit from the tricyclic antidepressant mirtazapine.
- Bias risk was high or unclear in 2 of the studies.
- Evidence was low or very low quality.
- Placebo and mirtazapine did not differ for any primary outcomes reported:
- Participant‐reported pain relief of 50% or greater.
- Patient Global Impression of Change (PGIC): no data available; and
- For some participant-reported secondary outcomes, mirtazapine bested placebo:
- Pain relief of ≥30% (47% vs 34%; risk difference, 0.13; 95% CI, 0.05-0.21);
- Pain intensity (standardized mean difference [SMD], −0.29; 95% CI, −0.46 to −0.13); and
- Sleep problems (SMD −0.23; 95% CI, −0.39 to −0.06).
- No improvements in other participant-reported measures (e.g., health-related QoL, fatigue, negative mood).
- Clinically relevant harm vs placebo for somnolence, weight gain, elevated liver enzymes.
- 3 randomized controlled trials, n=606, 7-13 weeks.
- Funding: National Institute for Health Research.
- Limitations of included studies, generally of low quality, according to the authors.