Evaluating the Role of Endogenous Opioids in Pain Relief from Spine Injections

Antagonism of Endogenous Opioids: Use in Interpretation of Injections

Phase 4 Interventional Middle Tennessee Research Institute · NCT06666621

This study is testing how well lumbar spine injections relieve pain in people with low back pain and arthritis, while also seeing if the body's natural painkillers play a role in that relief.

Quick facts

PhasePhase 4
Study typeInterventional
Enrollment33 (estimated)
Ages18 Years and up
SexAll
SponsorMiddle Tennessee Research Institute Academic / other
Locations1 site (Nashville, Tennessee)
Trial IDNCT06666621 on ClinicalTrials.gov

What this trial studies

This study investigates the pain relief effects of lumbar medial branch blocks (LMBB) in patients with low back pain and zygapophyseal joint arthritis. It aims to differentiate between the physiological effects of the nerve block and the placebo response by using naloxone, an opioid receptor antagonist, to block the body's endogenous opioids. By measuring pain relief before and after the administration of naloxone, the study seeks to enhance understanding of how these injections guide pain management. The findings could lead to improved treatment protocols for patients suffering from chronic low back pain.

Who should consider this trial

Good fit: Ideal candidates are adults experiencing low back pain for at least three months with significant symptoms despite conventional treatments.

Not a fit: Patients currently using opioid medications or those with certain spinal conditions may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could lead to more accurate pain management strategies for patients with low back pain.

How similar studies have performed: While the use of naloxone to assess placebo responses is innovative, similar studies have shown promise in understanding pain management, though this specific approach is relatively novel.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Capable of understanding and providing consent in English and capable of complying with the outcome instruments used
* ≥3 months low back pain with persistent limiting symptoms despite conventional treatment (physical therapy and oral medications)
* Low back pain NRS ≥ 4/10 in intensity on 7-day average and at time of lumbar medial branch block

Exclusion Criteria:

* Daily use of opioid medications or recreational drugs, or if using opioids PRN, report of opioid use within the 3 days prior to participating in the protocol
* Positive urine drug screen for opioid medication on the day of naloxone administration
* Allergy to naloxone
* Refusal of or failure to place IV
* Previous LMBB or LMBRN
* Known spine condition that may affect the ability to diagnose or treat facet pain or lead to spine surgery (e.g. instability, severe spinal stenosis, radiculopathy, previous spine operation resulting in alteration of anatomy targeted by LMBB or LMBRFN)
* Active medical condition that would limit the safety of naloxone administration (e.g. severe kidney or liver failure, unstable cardiac disease, infection, severe coagulopathy)
* Psychiatric, medical, neurologic, or pain-related disorder that may compromise the ability of the patient to accurately report changes in low back pain
* Requirement for procedural sedation to tolerate LMBB

Where this trial is running

Nashville, Tennessee

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Low Back PainZygapophyseal Joint Arthritislow back painzygapophysial joint arthritisendogenous opioidslumbar medial branch block
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.