Dextromethorphan in Fibromyalgia
Study Details
Study Description
Brief Summary
The objective of this protocol is to evaluate if Dextromethorphan (DXM) reduces Fibromyalgia (FM) pain. DXM is a drug found in several over-the-counter products, including cough suppressants. The drug may reduce FM pain by suppressing inflammation in the central nervous system. The investigators will be observing the effects of DXM on daily self-reported pain measures in people with FM. If DXM reduces FM pain, it will provide important information about the nature of FM pathophysiology.
| Condition or Disease | Intervention/Treatment | Phase |
|---|---|---|
|
Phase 2 |
Detailed Description
Fibromyalgia (FM) is a chronic, widespread pain syndrome. Individuals with FM frequently report body pain, fatigue, sleep issues, cognitive impairment, headaches, and other symptoms. The disease affects approximately 5% of women in the United States. Many of those patients suffer with decreased quality of life and loss of employment.
The precise pathological mechanism of FM is not yet understood, and there is no targeted treatment for the condition. One hypothesis of FM with prior scientific support is that pain is caused by abnormal inflammation of the brain. When microglia cells in the brain adopt an inflammatory state, they release chemicals that can cause neurons to increase the transmission of pain signals.
DXM has been used in previous research and demonstrated to suppress pain symptoms. When given at higher dosages (above 200mg), the medication acts as a dissociative agent. This dosage can reduce pain, but produces side-effects that can limit daily functioning. At lower dosages, however, DXM may reduce inflammatory aspects of chronic pain while not causing dissociative side effects.
In animal models, central inflammation can be reduced with intraperitoneal dosages of DXM of 0.1mg/kg. In an average U.S. woman, this dosage would translate to approximately 8mg. Because an oral versus intraperitoneal dosing route will be used, the dose will be raised to 10mg, administered twice a day (once in the morning and once at night). The investigator will examine the impact of 20mg total daily DXM on self-reported FM pain.
Study Design
Arms and Interventions
| Arm | Intervention/Treatment |
|---|---|
| Experimental: Dextromethorphan Participant will take one dextromethorphan 10mg capsule in the morning and at night. |
Drug: Dextromethorphan
(1)10 mg, by mouth, twice daily every 12 hours.
|
| Placebo Comparator: Placebo Participants will take one placebo capsule in the morning and at night. |
Drug: Placebo
1 capsule, by mouth, twice daily every 12 hours.
|
Outcome Measures
Primary Outcome Measures
- Daily self-reported pain severity [For the primary test of efficacy, average pain over the final 4 weeks of DXM condition contrasted with final 4 weeks of placebo condition.]
The primary outcome will be daily self-reported widespread pain severity, rated on a 0 - 100 scale (100 = worst pain possible).
Secondary Outcome Measures
- Daily self-reported physical activity [Test of efficacy will use average activity over the final 4 weeks of the DXM condition contrasted with final 4 weeks of placebo condition.]
Secondary outcome #1 is self-reported daily activity, rated from 0 - 100.
- Patient global impression of change [Over the 20-week placebo and DXM periods, we will contrast PGIC rating provided at the end of the placebo condition with PGIC rating provided at the end of the DXM condition.]
Secondary outcome #2 is the patient global impression of change (PGIC) measured in a seven point likert scale (from no change to a great deal better).
Eligibility Criteria
Criteria
Inclusion Criteria:
-
Severe chronic fatigue ≥6 consecutive months not due to ongoing exertion or other medical condition associated with fatigue;
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Daily self-reported pain of at least 4 out of 10;
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Meets American College of Rheumatology 2016 case definition criteria for FM;
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Able to attend UAB for all scheduled appointments;
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Can complete daily self-reports of pain and other symptoms for duration of project.
Exclusion Criteria:
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Blood draw contraindicated or otherwise not able to be performed;
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High-sensitivity C-reactive protein (HS-CRP) ≥ 10 mg/L;
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Erythrocyte sedimentation rate (ESR) >60 mm/hr;
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Positive rheumatoid factor;
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Positive anti-nuclear antibody (ANA);
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Abnormal thyroid stimulating hormone or free thyroxine;
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Diagnosed rheumatologic or auto-immune condition;
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Blood or clotting disorder;
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Use of blood thinning medication;
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Current use of MAOI
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Daily consumption of grapefruit juice
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Oral temperature >100˚F at baseline;
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Febrile illness or use of antibiotics in the 4 weeks before study commencement;
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Planned surgery or procedures during the study period, or operated on in the 4 weeks before study commencement;
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Pregnant or planning on becoming pregnant within 6 months, or currently breastfeeding
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Regular use of any anti-inflammatory medication (such as aspirin, ibuprofen, naproxen);
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Baseline HADS (Hospital Anxiety and Depression Scale) depression subscale score of ≥16;
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Current litigation or worker's compensation claim;
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Current participation in another treatment trial;
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Planned vaccination during the study period, or vaccinated in the 4 weeks before study commencement.
Contacts and Locations
Locations
| Site | City | State | Country | Postal Code | |
|---|---|---|---|---|---|
| 1 | University of Alabama of Birmingham | Birmingham | Alabama | United States | 35294 |
Sponsors and Collaborators
- University of Alabama at Birmingham
Investigators
- Principal Investigator: Jarred W Younger, PhD, University of Alabama at Birmingham
Study Documents (Full-Text)
None provided.More Information
Publications
None provided.- F161018005