Effect of Milnacipran on Pain in Fibromyalgia (Forest)
|Study Design:||Intervention Model: Single Group Assignment
Masking: None (Open Label)
Primary Purpose: Treatment
|Official Title:||Effects of a 12 Week Milnacipran 200 mg Treatment on Pain Perception and Pain Processing in Fibromyalgia - An Open Label Study|
- Concentration of norepinephrine in cerebrospinal fluid in response to experiemental pain before and after milnacipran treatment. [ Time Frame: 12 weeks ]The investigators will measure cerebrospinal fluid norepinephrine levels in response to painful heat stimuli before and after a 12 week course of milnacipran in fibromyalgia patients.
- Measure sensory thresholds for touch, pressure, and temperature pain [ Time Frame: 12 weeks ]Investigators will utilize quantitative sensory testing to assess changes in sensory thresholds among patients with fibromyalgia before and after a twelve (12) week course of milnacipran.
- Measure pain ratings and Fibromyalgia symptoms [ Time Frame: 12 weeks ]Fibromyalgia patients will be asked to keep a pain diary which assess spontaneous pain ratings daily, a subjective weekly assessment, as well as degree of improvement weekly during treatment period on a numeric rating scale.
- Measure concentrations of serotonin and substance P cerebrospinal fluid and plasma [ Time Frame: 12 weeks ]The investigators will measure cerebrospinal fluid and plasma concentrations of serotonin and substance P in CSF and plasma before and after twelve (12) weeks of treatment with milnacipran.
|Study Start Date:||February 2011|
|Study Completion Date:||January 2015|
|Primary Completion Date:||January 2015 (Final data collection date for primary outcome measure)|
Titrated Milnacipram doses
Titration to 200mg PO daily
Fibromyalgia (FM) is a chronic pain condition with significant morbidity. Current research suggests a primarily central mediation of the widespread pain including central sensitization at the spinal level and abnormal pain processing at the cerebral level. Findings in FM patients include abnormal neurotransmitter levels in cerebrospinal fluid (CSF), abnormal activation of cerebral pain processing areas and abnormal peripheral pain and sensory thresholds. Continuous low level spinal cord activation by primary nociceptive afferents (C and A delta fibers) is believed to significantly drive the central sensitization. One major spinal neurotransmitter released by these pain fibers is substance P (SP). Several studies have shown that FM patients have up to three times higher baseline SP levels in the CSF compared to controls. Since spinal neurotransmitter release and therefore nociceptive afferent activity is also regulated via a descending inhibitory pathway releasing norepinephrine (NE) and serotonin (5HT), decreased activity of this pain modulating system could also be involved in abnormal pain processing in FM. Indeed, there is support in the literature for decreased CSF levels of both NE and 5HT or their metabolites. Milnacipran, a NE and 5HT reuptake inhibitor, has been shown to potentially effectively reduce FM pain and symptoms of FM by affecting the above pathologies.
The investigators propose an open label clinical trial with milnacipran 200 mg over 12-weeks in order to investigate the pain pathway in FM patients at peripheral and spinal levels before and after treatment. In addition, the investigators will assess pain intensity and symptoms of FM before, during and after treatment. To determine if there are peripheral effects, the investigators will characterize the systemic neurotransmitter release and their metabolites in plasma. The investigators will also measure the heart rate variability using an electrocardiogram to look for effects on the sympathetic nervous system.
Please refer to this study by its ClinicalTrials.gov identifier: NCT01288807
|United States, California|
|UCSD Medical Center, La Jolla|
|San Diego, California, United States, 92037|
|Principal Investigator:||Tobias Moeller-Bertram, MD, PhD, MAS||University of California, San Diego|