Low Dose Naltrexone for Chronic Pain From Arthritis
Condition: Osteoarthritis; Arthritis, Rheumatoid; Arthritis, Psoriatic
MeSH terms: Arthritis; Osteoarthritis; Arthritis, Rheumatoid; Arthritis, Psoriatic; Chronic Pain
Intervention: Naltrexone; Placebo
Intervention description: One 4.5 mg capsule each evening; One capsule each evening
Intervention MeSH terms: Naltrexone
Phase: Phase 2
Study type: Interventional
Primary purpose: Treatment
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: Double (Participant, Investigator)
Enrollment: 29.0
Sex: All
Healthy volunteers: No
Keywords: Pain management; Naltrexone; Controlled clinical trials, randomized

Summary:

      Over 100 million Americans report chronic pain. Veterans are disproportionately affected for
      multiple reasons, including injuries and post-traumatic stress disorder. Treatment for
      chronic pain is a priority research area for the VA. One of the most common causes of chronic
      pain is osteoarthritis (OA). OA is attributable to "wear and tear," but reasons for pain are
      complex. Inflammatory arthritis (IA) includes multiple severe diseases that affect 2-3% of
      persons and require treatment with immune-suppressive drugs to prevent joint destruction.
      Pain often persists despite effective treatment. Pain in arthritis results from multiple
      sources: inflammation, perception of pain in the joint, and interpretation of pain by the
      brain. Unfortunately, management of pain in arthritis remains a challenge. Low dose
      naltrexone is a widely used but unproven "alternative" approach to chronic pain. It is
      attractive for study because it is safe and is proposed to work on all three pathways that
      contribute to pain. A small but high-quality clinical trial is needed to determine whether to
      invest in definitive studies.
    

Eligibility criteria:

        Inclusion Criteria:

        Patients must meet all of the following criteria in order to be eligible for enrollment:

          -  Veteran or otherwise eligible for VA benefits, able to travel to VA Boston

          -  One or more of the following chronic conditions:

               -  osteoarthritis

               -  rheumatoid arthritis

               -  non-axial spondyloarthritis

          -  Average daily pain interference with function (average of the 7 parts of question 9 on
             the Brief Pain Inventory) rated at least 4 on a scale of 0-10, and no higher than 9

          -  No change in medication in the past 8 weeks made with the expectation of improving
             pain

          -  No plan to start another medication or a non-pharmacologic treatment regimen likely to
             affect pain during the next 16 weeks

          -  Age at least 18

          -  Registered for medical care in the VA Boston Healthcare System

          -  Capable of informed consent, and willingness to comply with study procedures,
             including receipt of weekly phone calls from the study coordinator

        Exclusion Criteria:

        Any of the following requires exclusion from participation:

          -  Current use of opioids including tramadol

          -  Pregnant, breast feeding, or unwilling to engage in contraceptive practices if
             sexually active and capable of conceiving

          -  Schizophrenia, bipolar disorder, or poorly controlled depression or anxiety

          -  Previous use of low-dose naltrexone

          -  Back pain described by the patient as greater in severity than arthritic pain in a
             non-axial location

          -  Significant kidney disease, defined as glomerular filtration rate < 30 ml/min

          -  Liver cirrhosis. There is no specific screening procedure to exclude cirrhosis.

          -  Painful peripheral neuropathy. There is no specific screening procedure.

          -  Plan to have surgery during the next 16 weeks

          -  Inconsistency in self-reporting at the screening visit. BPI, PainDETECT, WOMAC, and
             PROMIS-29 all contain 0-10 scales of average pain intensity, although the times listed
             vary from 1-4 weeks. The severity reported on these three scales cannot differ by more
             than 1.

          -  Other qualitative circumstances that the investigator feels would make the patient a
             poor candidate for this clinical trial, such as an unstable social situation or
             unreliable transportation