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Recruiting Phase 2 NCT04939623

NCT04939623 Novel Use of Probenecid to Alleviate Symptoms of Opioid Withdrawal

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Clinical Trial Summary
NCT ID NCT04939623
Status Recruiting
Phase Phase 2
Sponsor University of Calgary
Condition Chronic Pain
Study Type INTERVENTIONAL
Enrollment 40 participants
Start Date 2023-10-31
Primary Completion 2026-12-31

Eligibility & Interventions

Sex All sexes
Min Age 18 Years
Max Age 80 Years
Study Type INTERVENTIONAL
Interventions
Probenecid

Eligibility Fast-Check

Enter your details for a quick preliminary check. This does not replace medical advice.

What to Expect as a Participant

You will actively receive the study intervention — which may be a drug, biologic, device, or procedure.

In Phase 2, researchers evaluate early signs of effectiveness. You may be randomized to receive the active treatment or a comparator. Monitoring continues closely.

This trial targets 40 participants in total. It began in 2023-10-31 with a primary completion date of 2026-12-31.

⚠ This information is for research awareness only. Always consult your physician before joining any clinical trial. Participation is voluntary and you may withdraw at any time.

Brief Summary

The proposed clinical trial will address the problem of opioid withdrawal. Opioids are essential for pain-relief in the short term, but their continued use is associated with a host of adverse effects. People living with chronic pain who were initiated on opioid therapy now find themselves with a major life-changing problem - dependence on opioid medications. Opioid withdrawal symptoms are a key barrier to decreasing or stopping their opioid medication. Currently, there are few medications that ameliorate the symptoms of opioid withdrawal. This problem is a major part of the opioid crisis in Canada, and impacts people across all demographics and socioeconomic status. A misconception is that only individuals with opioid use disorder are susceptible to opioid withdrawal; on the contrary, appropriate use of prescription opioids to manage pain can lead to significant symptoms of opioid withdrawal when it is reduced or stopped. Patients in Alberta who are at risk for opioid withdrawal, either from prescribed use or misuse will be primarily impacted by this trial. The investigators have recently explored the underlying causes of opioid withdrawal and identified an important target in the spinal cord that is responsible for producing withdrawal symptoms in rats and mice. The target, a protein called pannexin-1 (Panx1), is located throughout the body, specifically in the brain and spinal cord. Using sophisticated biochemical, genetic, and pharmacological techniques, the investigators demonstrated how Panx1 on immune cells is implicated in the production of opioid withdrawal symptoms after cessation of fentanyl and morphine in opioid dependent rodents. The investigators then attenuated these symptoms of withdrawal using probenecid, a drug which inherently blocks Panx1 activity. Because probenecid is a safe and clinically available drug, the findings could be immediately translated into clinical therapy to support people who are struggling with the symptoms of opioid withdrawal and provide clinicians with a safe and effective option for caring for this population.

Eligibility Criteria

Inclusion Criteria: 1. Adults with chronic pain. Age greater than or equal to 18 years on the day of enrolment. 2. Subjects are currently taking a daily opioid pain medication and planning to taper the dose. 3. Participants complete at least one voluntary opioid dose reduction in the twelve-week study period. 4. Glomerular filtration rate (GFR) \> 50 mL/min 5. Capable of providing informed consent Exclusion Criteria: 1. Allergy to probenecid or related drugs 2. History of uric acid renal calculi, if known to be urate calculi. If unknown type, then any history of renal calculi. 3. Known G6PD deficiency 4. Active gout in any joint 5. Current use of drugs whose exposure may be prolonged, or risk of toxicity increased when used in combination with probenecid: 1. Penicillins, specifically ampicillin, penicillin G sodium, and piperacillin 2. Carbapenems, specifically doripenem and meropenem 3. Lorazepam, midazolam, nitrazepam 4. Ketorolac 5. Oseltamivir 6. Methotrexate 7. Mycophenolate 6. Current use of drugs which may mask symptoms of withdrawal: a. Clonidine, lofexidine, tizanidine 7. Current use of drugs which may diminish the effect of probenecid: a. High dose salicylates including greater than 325 mg PO daily of acetylsalicylic acid (ASA) 8. Pregnancy or breastfeeding 9. Any major comorbid medical condition which might impair follow-up or result in a safety risk to the participant 10. Participation in another clinical trial investigating a drug, medical device, or a medical procedure during the 30 days prior to enrolment. \-

Contact & Investigator

Central Contact

Tammy Eberle

✉ tammy.eberle@primarycarealberta.ca

📞 1-403-943-9900

Principal Investigator

Lori Montgomery, MD

PRINCIPAL INVESTIGATOR

University of Calgary

Frequently Asked Questions

Who can join the NCT04939623 clinical trial?

This trial is open to participants of all sexes, aged 18 Years or older, up to 80 Years, studying Chronic Pain. Full inclusion and exclusion criteria are listed in the Eligibility Criteria section. Always confirm your eligibility with the research team before applying.

What phase is the NCT04939623 trial and what does that mean for participants?

Phase 2 trials evaluate whether the treatment shows signs of effectiveness while continuing to monitor safety. More participants are enrolled than in Phase 1 to help refine the treatment protocol.

Is NCT04939623 currently recruiting?

Yes, NCT04939623 is actively recruiting participants. Contact the research team at tammy.eberle@primarycarealberta.ca for enrollment information.

Where is the NCT04939623 trial being conducted?

This trial is being conducted at Calgary, Canada.

Who is sponsoring the NCT04939623 clinical trial?

NCT04939623 is sponsored by University of Calgary. The principal investigator is Lori Montgomery, MD at University of Calgary. The trial plans to enroll 40 participants.

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ClinicalMetric — Independent clinical trial intelligence platform. Not affiliated with NIH, ClinicalTrials.gov, the U.S. FDA, or any pharmaceutical company, hospital, or clinical research organization. Trial data is sourced from ClinicalTrials.gov for informational purposes only and does not constitute medical advice. Do not make any treatment, enrollment, or health decisions based solely on information found here — always consult a qualified healthcare professional. Full Disclaimer  ·  Last Reviewed: July 2026  ·  Data Methodology