Immune Effects of Low-dose Naltrexone in ME/CFS

The Immune Effects of Low-dose Naltrexone in People With Myalgic Encephalopathy/Chronic Fatigue Syndrome (ME/CFS)

The main objective of this study is to test if naltrexone, when taken in low doses, has an anti-inflammatory effect that may be associated with positive clinical outcomes in people with chronic fatigue syndrome (CFS). In part, the present study, is a continuation of prior work in which we showed that chronic fatigue symptoms are associated with immune activity, and that low-dose naltrexone might exert anti-inflammatory effects in fibromyalgia, which is thought to share some pathophysiological and clinical characteristics with CFS.

Inclusion Criteria:

1. Meet the 1994 Case Definition criteria for CFS (assessed through semi-structured interview and the DePaul University Fatigue Questionnaire):

• Criteria:

  • Severe chronic fatigue ≥6 consecutive months not due to ongoing exertion or other medical condition associated with fatigue;
  • Fatigue interferes with daily activities and work;
  • Reports ≥4 symptoms that started with or after the fatigue, from:

• Post-exertion malaise >24 hours

• Unrefreshing sleep

• Short-term memory or concentration impairment

• Muscle pain

• Joint pain without swelling or redness

• Headaches of a new type/pattern/severity

• Lymph node tenderness

• Frequent or recurring sore throat 3. CFS symptoms for ≥12 months 4. Participant completes daily self-report during the 4-week baseline period; 5. Able to attend UAB on all scheduled appointments

Exclusion Criteria:

1. Blood draw contraindicated or otherwise not able to be performed
2. High-sensitivity c-reactive protein (HS-CRP) ≥3 mg/L
3. Erythrocyte sedimentation rate (ESR) >60 mm/hr
4. Positive rheumatoid factor
5. Positive anti-nuclear antibody (ANA)
6. Levels of thyroid stimulating hormone or free thyroxine outside UAB lab reference values
7. Diagnosed rheumatological or auto-immune condition
8. Clotting disorder
9. Use of blood thinning medication
10. Oral temperature >100˚F at baseline
11. Febrile illness or use of antibiotics in the 4 weeks before study commencement;
12. Planned surgery or procedures during the study period, or operated on in the 4 weeks before study commencement
13. Pregnant or planning on becoming pregnant within 6 months
14. Regular use of any anti-inflammatory medication (such as aspirin, ibuprofen, naproxen)
15. Known allergy or adverse effects following naltrexone or naloxone administration
16. Opioid use (self-reported or positive on urine test)
17. Significant psychological comorbidity that in the discretion of the investigator compromises study integrity and/or a baseline HADS depression subscale score of ≥16
18. Current litigation or worker's compensation claim
19. Current participation in another treatment trial
20. Vaccinated in the 4 weeks before study commencement (vaccination during the study period is allowed as long as the drug is administered at least 4 weeks prior to a study blood draw).