Opioid Taper Study
Condition: Chronic Pain
MeSH terms: Chronic Pain
Study type: Observational

Summary: 
      The purpose of this study is to determine the effect of opioid taper on pain sensitivity in
      patients with chronic pain. In a well-characterized sample of men and women with chronic
      neuropathic pain on high-dose opioid therapy, experimental pain responses (cold-pressor,
      quantitative sensory testing) will be serially described over the course of and following an
      individualized opioid taper. In addition, functional improvements and subject-level
      predictors of response will be described.
    

Detailed description: 
      The overall Specific Aim of this proposal is to determine the effect of opioid taper on pain
      sensitivity in patients with chronic pain. Specifically, in a well-characterized sample of
      men and women with chronic neuropathic pain and receiving high-dose opioid therapy (>100mg
      morphine equivalents/day [MED]), experimental pain responses will be serially described over
      the course of an individualized opioid taper to a safer dose of 90mg MED for up to 12 months.
      Changes will be inspected within-subject over time, and pain perception will be measured with
      two valid and reliable experimental pain induction techniques commonly used to measure OIH
      (cold-pressor, quantitative sensory testing); in addition, related functional improvements
      and subject-level predictors of response will be described.

      Hypothesis 1. Subjects undergoing opioid taper will have improved pain responses over time
      compared to within-subject baseline as measured by cold-pressor and quantitative sensory pain
      testing.

      Hypothesis 2. Improvements in experimental pain responses will be positively related to
      improved functional outcomes compared to within-subject baseline as measured by the PROMIS
      physical, mental and social health measures.

      Hypothesis 3. Degree of improvement in experimental pain responses related to opioid taper
      will be predicted by demographic, pain, and opioid use history characteristics of the
      subject.

      Data showing that pain perception improves as opioids are withdrawn would provide an
      evidence-based, mechanistic rationale for opioid taper in patients with chronic pain and have
      the potential to support a sea-change in opioid prescription practices. In that ongoing
      opioid therapy brings with it significant health risks for the patient and the community, it
      is critical that empirical evidence of its efficacy be demonstrated to balance the benefits
      with the risks of adverse events, potential misuse and abuse, and patient safety.
    

Intervention name(s): Opioid Taper Pain perception
Intervention type(s): Other
Intervention description(s): Pain Responses: The primary dependent variable, pain, will be measured using two highly reliable and valid pain induction techniques, the CPT and QST, employing procedures consistent with those described in the literature. Order of pain testing will vary, and three aspects of the pain response will be captured at each study session: evoked pain; temporal summation; and conditioned pain modulation, which map on to the hypothesized peripheral, spinal and supra-spinal mechanisms of OIH. Protocols for each assay have been uploaded.
Intervention MeSH terms: Analgesics, Opioid
Observational model: Case-Only
Time perspective: Prospective
Sampling method: Probability Sample
Study population: 
        The sample will consist of 25 male and female adults with chronic neuropathic pain on
        opioid therapy and preparing to voluntarily undergo a prescribed opioid taper.