A dose-response study of the effects of intravenous midazolam on cold pressor-induced pain

Feasibility of Web-Based Single-Session Empowered Relief in Patients With Chronic Pain Taking Methadone or Buprenorphine: Protocol for a Single-Arm Trial

BACKGROUND

Chronic pain affects tens of millions of US adults and continues to rise in prevalence. Nonpharmacologic behavioral pain treatments are greatly needed and yet are often inaccessible, particularly in settings where medication prescribing is prioritized.

OBJECTIVE

This study aims to test the feasibility of a live-instructor, web-based 1-session pain relief skills class in an underserved and potentially at-risk population: people with chronic pain prescribed methadone or buprenorphine either solely for pain or for comorbid opioid use disorder (OUD).

METHODS

This is a national, prospective, single-arm, uncontrolled feasibility trial. The trial is untethered from medical care; to enhance participants' willingness to join the study, no medical records or drug-monitoring records are accessed. At least 45 participants will be recruited from outpatient pain clinics and from an existing research database of individuals who have chronic pain and are taking methadone or buprenorphine. Patient-reported measures will be collected at 6 time points (baseline, immediately post treatment, 2 weeks, and months 1-3) via a web-based platform, paper, or phone formats to include individuals with limited internet or computer access and low literacy skills. At baseline, participants complete demographic questions and 13 study measures (Treatment Expectations, Body Pain Map, Medication Use, Pain Catastrophizing Scale [PCS], Patient-Reported Outcomes Measurement Information System [PROMIS] Measures, and Opioid Craving Scale). Immediately post treatment, a treatment satisfaction and acceptability measure is administered on a 0 (very dissatisfied) to 10 (completely satisfied) scale, with 3 of these items being the primary outcome (perceived usefulness, participant satisfaction, and likelihood of using the skills). At each remaining time point, the participants complete all study measures minus treatment expectations and satisfaction. Participants who do not have current OUD will be assessed for historical OUD, with presence of OUD (yes or no), and history of OUD (yes or no) reported separately. Feasibility threshold is set as an overall group treatment satisfaction rating of 8 of 10. In-depth qualitative interviews will be conducted with about 10 participants to obtain additional data on patient perceptions, satisfactions, needs, and wants. To assess preliminary efficacy, we will examine changes in pain catastrophizing, pain intensity, pain bothersomeness, sleep disturbance, pain interference, depression, anxiety, physical function, global impression of change, and opioid craving at 1 month post treatment.

RESULTS

This project opened to enrollment in September 2021 and completed the recruitment in October 2023. The data collection was completed in February 2024. Results are expected to be published in late 2024.

CONCLUSIONS

Results from this trial will inform the feasibility and preliminary efficacy of Empowered Relief in this population and will inform the design of a future randomized controlled trial testing web-based Empowered Relief in chronic pain and comorbid OUD.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05057988; https://clinicaltrials.gov/study/NCT05057988.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/53784.

Low-dose fentanyl reduces pain perception, muscle sympathetic nerve activity responses, and blood pressure responses during the cold pressor test

Our knowledge about how low-dose (analgesic) fentanyl affects autonomic cardiovascular regulation is primarily limited to animal experiments. Notably, it is unknown if low-dose fentanyl influences human autonomic cardiovascular responses during painful stimuli in humans. Therefore, we tested the hypothesis that low-dose fentanyl reduces perceived pain and subsequent sympathetic and cardiovascular responses in humans during an experimental noxious stimulus. Twenty-three adults (10 females/13 males; 27 ± 7 yr; 26 ± 3 kg·m^-2, means ± SD) completed this randomized, crossover, placebo-controlled trial during two laboratory visits. During each visit, participants completed a cold pressor test (CPT; hand in ∼0.4°C ice bath for 2 min) before and 5 min after drug/placebo administration (75 μg fentanyl or saline). We compared pain perception (100-mm visual analog scale), muscle sympathetic nerve activity (MSNA; microneurography, 11 paired recordings), and beat-to-beat blood pressure (BP; photoplethysmography) between trials (at both pre- and postdrug/placebo timepoints) using paired, two-tailed t tests. Before drug/placebo administration, perceived pain (P = 0.8287), ΔMSNA burst frequency (P = 0.7587), and Δmean BP (P = 0.8649) during the CPT were not different between trials. After the drug/placebo administration, fentanyl attenuated perceived pain (36 vs. 66 mm, P < 0.0001), ΔMSNA burst frequency (9 vs. 17 bursts/min, P = 0.0054), and Δmean BP (7 vs. 13 mmHg, P = 0.0174) during the CPT compared with placebo. Fentanyl-induced reductions in pain perception and Δmean BP were moderately related (r = 0.40, P = 0.0641). These data provide valuable information regarding how low-dose fentanyl reduces autonomic cardiovascular responses during an experimental painful stimulus.

Abuse liability of oxycodone as a function of pain and drug use history

The relationship between pain and prescription opioid abuse is poorly understood. Determining whether a patient is seeking additional opioid medications in order to alleviate pain or to abuse the drugs can be difficult. The present study was designed to evaluate two variables that may influence the abuse liability of opioids: drug use history and the presence or absence of experimentally induced pain. Eighteen healthy participants completed this outpatient study. One group was abusing prescription opioids (N=9) and one group had used prescription opioids medically but did not abuse them (N=9). All participants completed twelve sessions during which the effects of orally delivered oxycodone (0, 15, 30mg/70kg, PO) were examined. One dose was tested per day under double-blind conditions and sessions were separated by at least 48h. During the first "sample" session each week, participants were given $10 and the dose that was available later that week. During the second "choice" session, participants could self-administer either money or the previously sampled dose. Six sessions involved repeated hand immersions in cold water (4 degrees C) and six sessions involved immersions in warm water (37 degrees C). Most of the positive subjective effects of oxycodone were similar between the groups, but oxycodone self-administration significantly differed between groups. Non-abusers self-administered active doses of oxycodone only when they were in pain while abusers self-administered oxycodone regardless of the pain condition. These data suggest that an assessment of the reinforcing effects of opioids may be a sensitive method for differentiating opioid abusers from non-abusers.