Trial reportRegional anesthesia and pain medicine
Endogenous opioid inhibition of chronic low-back pain influences degree of back pain relief after morphine administration.
Trial report in Regional anesthesia and pain medicine. The graph could read no effect estimate from its abstract, so it casts no vote on the map. It is linked to 3 registered trials, which are not on this map. Cited by 16 papers.
What it found
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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Reduced Opioid Analgesic Requirements Via Improved Endogenous Opioid Function
Evaluating Specific and Non-Specific Mechanisms in Two Distinct Complementary/Integrative Interventions for Chronic Pain
Stress and Opioid Misuse Risk: The Role of Endogenous Opioid and Endocannabinoid Mechanisms
Who cites it
16 citing papers in PubMed, 23 citations in OpenAlex.
- Trial
- Endogenous Opioid Function and Responses to Morphine: The Moderating Effects of Anger Expressiveness.The journal of pain · 2017Trial
- Trial
- Do Resting Plasma β-Endorphin Levels Predict Responses to Opioid Analgesics?The Clinical journal of pain · 2017Trial
- The Contribution of Differential Opioid Responsiveness to Identification of Opioid Risk in Chronic Pain Patients.The journal of pain · 2015Trial
- Prospective evaluation of cerebrospinal fluid concentrations of β-Endorphin as a predictor of opioid use after scheduled cesarean delivery.BMC pregnancy and childbirth · 2025Article
- Predicting Extent of Opioid Use Following Cardiac Surgery: A Pilot Study.Journal of cardiothoracic and vascular anesthesia · 2025Observational
- A Theoretical Endogenous Opioid Neurobiological Framework for Co-occurring Pain, Trauma, and Non-suicidal Self-injury.Current pain and headache reports · 2022Review
- Endogenous opioid systems alterations in pain and opioid use disorder.Frontiers in systems neuroscience · 2022Review
- β-endorphin at the intersection of pain and cancer progression: Preclinical evidence.Neuroscience letters · 2021Article
- [Diagnostic value of endogenous morphine in childhood sepsis].Zhongguo dang dai er ke za zhi = Chinese journal of contemporary pediatrics · 2018Article
- Ethnic Differences in the Effects of Naloxone on Sustained Evoked Pain: A Preliminary Study.Diversity and equality in health and care · 2017Article
- Building a Biopsychosocial Conceptual Framework to Explore Pressure Ulcer Pain for Hospitalized Patients.Healthcare (Basel, Switzerland) · 2016Article
- Personalized pain medicine: pipe dream or reality?Anesthesiology · 2015Article
- Article
- AAAPT Diagnostic Criteria for Acute Pain Following Breast Surgery.The journal of painArticle
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
7 authors at 3 institutions in 1 country.
Funding
Abstract
BACKGROUND AND
objectivesFactors underlying differential responsiveness to opioid analgesic medications used in chronic pain management are poorly understood. We tested whether individual differences in endogenous opioid inhibition of chronic low-back pain were associated with the magnitude of acute reductions in back pain ratings after morphine administration.
methodsIn randomized counterbalanced order over three sessions, 50 chronic low-back pain patients received intravenous naloxone (8 mg), morphine (0.08 mg/kg), or placebo. Back pain intensity was rated predrug and again after peak drug activity was achieved using the McGill Pain Questionnaire-Short Form (Sensory and Affective subscales, VAS Intensity measure). Opioid blockade effect measures to index degree of endogenous opioid inhibition of back pain intensity were derived as the difference between predrug to postdrug changes in pain intensity across placebo and naloxone conditions, with similar morphine responsiveness measures derived across placebo and morphine conditions.
resultsMorphine significantly reduced back pain compared with placebo (McGill Pain Questionnaire-Short Form Sensory, VAS; P < 0.01). There were no overall effects of opioid blockade on back pain intensity. However, individual differences in opioid blockade effects were significantly associated with the degree of acute morphine-related reductions in back pain on all measures, even after controlling for effects of age, sex, and chronic pain duration (P < 0.03). Individuals exhibiting greater endogenous opioid inhibition of chronic back pain intensity reported less acute relief of back pain with morphine.
conclusionsMorphine appears to provide better acute relief of chronic back pain in individuals with lower natural opioidergic inhibition of chronic pain intensity. Possible implications for personalized medicine are discussed.
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What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.