Dextromethorphan in Fibromyalgia
Condition: Fibromyalgia
MeSH terms: Fibromyalgia; Myofascial Pain Syndromes
Intervention: Dextromethorphan; Placebo
Intervention description: (1)10 mg, by mouth, twice daily every 12 hours.; 1 capsule, by mouth, twice daily every 12 hours.
Intervention MeSH terms: Dextromethorphan
Phase: Phase 2
Study type: Interventional
Primary purpose: Other
Allocation: Non-Randomized
Intervention model: Crossover Assignment
Masking: Single (Participant)
Masking description: The participant will not know when they are taking placebo or the study medication.
Enrollment: 27.0
Sex: Female
Minimum age: 23 Years
Maximum age: 65 Years
Healthy volunteers: No
Keywords: Fibromyalgia

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.
    

Eligibility criteria:

        Inclusion Criteria:

          1. Severe chronic fatigue ≥6 consecutive months not due to ongoing exertion or other
             medical condition associated with fatigue;

          2. Daily self-reported pain of at least 4 out of 10;

        3. Meets American College of Rheumatology 2016 case definition criteria for FM;

        4. Able to attend UAB for all scheduled appointments;

        5. Can complete daily self-reports of pain and other symptoms for duration of project.

        Exclusion Criteria:

          1. Blood draw contraindicated or otherwise not able to be performed;

          2. High-sensitivity C-reactive protein (HS-CRP) ≥ 10 mg/L;

          3. Erythrocyte sedimentation rate (ESR) >60 mm/hr;

          4. Positive rheumatoid factor;

          5. Positive anti-nuclear antibody (ANA);

          6. Abnormal thyroid stimulating hormone or free thyroxine;

          7. Diagnosed rheumatologic or auto-immune condition;

          8. Blood or clotting disorder;

          9. Use of blood thinning medication;

         10. Current use of MAOI

         11. Daily consumption of grapefruit juice

         12. Oral temperature >100˚F at baseline;

         13. Febrile illness or use of antibiotics in the 4 weeks before study commencement;

         14. Planned surgery or procedures during the study period, or operated on in the 4 weeks
             before study commencement;

         15. Pregnant or planning on becoming pregnant within 6 months, or currently breastfeeding

         16. Regular use of any anti-inflammatory medication (such as aspirin, ibuprofen,
             naproxen);

         17. Baseline HADS (Hospital Anxiety and Depression Scale) depression subscale score of
             ≥16;

         18. Current litigation or worker's compensation claim;

         19. Current participation in another treatment trial;

         20. Planned vaccination during the study period, or vaccinated in the 4 weeks before study
             commencement.