Reduced Opioid Analgesic Requirements Via Improved Endogenous Opioid Function

Chronic Pain Clinical Trial

Official title: Reduced Opioid Analgesic Requirements Via Improved Endogenous Opioid Function

Status Completed

Clinical Trial Summary

Chronic Pain (CP) management has increasingly utilized long-term opioid analgesic therapy, a change associated with increased opioid abuse (via greater exposure in vulnerable individuals), non-pain health consequences (hormone changes, falls), and a dramatic rise in opioid-related overdoses and deaths. Treatment strategies that minimize the need for chronic high-dose opioids are sorely needed. This project will test the novel hypothesis that effective pain relief can be achieved at lower opioid analgesic doses by increasing levels of endogenous opioids (EOs).

Clinical Trial Description

There are three separate goals of the study: 1) test the effects of the intervention (versus control) on clinical outcomes, 2) test for endogenous opioid mechanisms of the intervention (indexed by the difference in laboratory evoked pain response between placebo and naloxone drug conditions), and 3) test the effects of the intervention on morphine responses (indexed by the difference in evoked pain response between placebo and morphine laboratory drug conditions).

This project will determine whether enhancing endogenous opioids (via aerobic exercise training) permits achieving desired levels of analgesia with lower dosages of opioid analgesics, and fewer side effects and abuse-relevant drug effects. This 4 year project will test study hypotheses in a sample of 116 chronic low back pain patients. The study will have two key elements: 1) a randomized, controlled aerobic exercise manipulation in CP patients completing daily electronic pain diaries and 2) laboratory evoked thermal pain protocols pre- and post-exercise permitting direct examination of changes in both opioid analgesic effects (in response to a series of incremental morphine doses) and EO activity (indexed by comparing pain responses after placebo vs. opioid blockade).

The study will use a 6 week supervised aerobic exercise manipulation, with subjects randomly assigned to the exercise protocol or a no exercise control condition.

The study will employ a mixed between/within-subjects design using double-blind, counterbalanced, placebo-controlled administration of both an opioid antagonist (naloxone) and an opioid agonist (morphine). All participants will undergo three identical laboratory pain-induction sessions (each ≈5 days apart) prior to randomization to experimental condition, and again at the end of the 6 week exercise manipulation period (regardless of exercise group assignment) during which they will receive the 3 study drugs and participate in controlled laboratory evaluation of evoked thermal pain responsiveness. ;

Related Conditions & MeSH terms

• Chronic Pain

• NCT number: NCT02469077
• Study type: Interventional
• Source: Vanderbilt University Medical Center
• Status: Completed
• Phase: N/A
• Start date: August 2015
• Completion date: September 2019