E1 ReplicatedModerate confidencePEM not requiredRCTPeer-reviewedReviewed
Standard · 3 min
Effect of Milnacipran Treatment on Ventricular Lactate in Fibromyalgia: A Randomized, Double-Blind, Placebo-Controlled Trial.
Natelson, Benjamin H, Vu, Diana, Mao, Xiangling et al. · The journal of pain · 2015 · DOI
Quick Summary
This study tested whether a medication called milnacipran could reduce brain inflammation and pain in fibromyalgia patients. Researchers measured a chemical called lactate in the brain using a special MRI scan and found that fibromyalgia patients had higher levels than healthy people. After 8 weeks of treatment, patients taking milnacipran showed lower lactate levels and less pain compared to those taking placebo, suggesting the medication may work by reducing brain inflammation.
Why It Matters
This study is significant because it identifies a potential biological marker (ventricular lactate) for central inflammation in chronic pain conditions and demonstrates that a currently-approved medication can reduce both this marker and symptoms. For ME/CFS patients and researchers, it supports the hypothesis that elevated lactate may indicate neuroinflammation in post-exertional malaise and other central nervous system symptoms, opening possibilities for targeting similar pathways.
Observed Findings
Fibromyalgia patients had significantly higher baseline ventricular lactate than healthy controls
Milnacipran treatment reduced ventricular lactate levels compared to both baseline and placebo group
Milnacipran reduced pain severity compared to placebo
A significantly larger proportion of milnacipran-treated patients showed concurrent decreases in both lactate and pain versus placebo
Milnacipran did not improve performance on cognitive attention and executive function tests
Inferred Conclusions
Ventricular lactate elevation may serve as a biomarker for therapeutic response in fibromyalgia
Milnacipran may work by reducing central neuroinflammation and glial activation
The mechanism of pain relief in fibromyalgia may involve reduction of brain lactate and associated inflammatory state
Cognitive deficits in fibromyalgia may not be directly linked to lactate-mediated inflammation or may require different treatment approaches
Remaining Questions
Why does milnacipran reduce lactate and pain in some patients but not others, and what predicts treatment response?
What This Study Does Not Prove
This study does not prove that milnacipran is effective for ME/CFS, as it examined only fibromyalgia patients—a different diagnosis with overlapping but distinct pathophysiology. It also does not establish that lactate reduction directly causes pain improvement (correlation does not prove causation), and the fact that lactate remained elevated after treatment raises questions about whether this biomarker fully explains therapeutic response. The lack of cognitive improvement despite lactate reduction suggests the mechanism may be more complex than initially hypothesized.
About the PEM badge: “PEM required” means post-exertional malaise was an explicit required diagnostic criterion for participant inclusion in this study — not that PEM was studied, observed, or discussed. Studies using criteria that do not require PEM (e.g. Fukuda, Oxford) are tagged “PEM not required”. How the atlas works →
Contribute
Private, reviewed by a human. Not a public comment thread.