A Phase 2/3 interventional study of 24-IU oxytocin and 48-IU oxytocin in Chronic Pain, sponsored by Memorial University of Newfoundland. Active, not recruiting at 3 sites in Canada. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-02-18.
Sponsored by Memorial University of Newfoundland · Phase 2/3, Interventional, and Treatment
One in five Canadians live with chronic pain, defined as pain that lasts longer than 3-months. Living with chronic pain has a detrimental impact on physical health, emotional health, and quality of life. Current treatments rarely result in pain relief and often do not meaningfully improve physical or emotional function. Further, medication used to treat pain often causes unwanted symptoms. There is a need to develop new treatments to help manage chronic pain. The use of a nasal spray containing manufactured oxytocin may improve pain management. Oxytocin is produced in the human body and has been shown to impact the pain pathway in animals. Our project tests whether the use of a nasal spray containing oxytocin will improve pain and function in men and women who live with chronic pain. Men and women with chronic nerve, muscle, or pelvic pain will be recruited in Vancouver, Calgary, and St. John's. Each person will be assigned to complete three interventions in a random order. Each intervention involves using a nasal spray twice per day over a 2-week period. The nasal spray will contain a small dose of oxytocin during one intervention and a medium dose during the second intervention. The nasal spray during the final intervention will have no oxytocin. This final intervention is a control intervention that will allow us to measure the effect of simply taking a nasal spray (i.e., the impact of expectation). Participants and researchers will not know which interventions involve the use of oxytocin. Participants will rate their pain and function each day throughout each task. The investigators will calculate each person's score on pain and function. The investigators will test whether participants report less pain and better function when they use oxytocin compared to the control. The results of this project may improve pain, function, and quality of life among those who live with chronic pain.
Background and Importance: Chronic pain affects 1 in 5 Canadians and is associated with considerable burden, both individual (disability, reduced physical and emotional function) and economic ($43 billion annual cost to the economy). Available treatments for chronic pain rarely resolve symptoms, may be associated with addiction and often do not improve function. There is a need for analgesics that are non-addictive, have low adverse effect profiles, and offer effective relief.
Our work suggests that oxytocin (OT), a neuropeptide produced in the hypothalamus, may be a safe and effective adjuvant analgesic for a broad patient population. There are three mechanisms through which OT may decrease pain sensitivity: 1) a direct hypothalamo-spinal projection transports OT to the dorsal horn, reducing pain signaling from the periphery to the brain; 2) binding to opioid receptors and stimulating endogenous opioid release in the brain; and 3) improving mood, anxiety, and stress. Our team published a systematic review of the effect of OT on pain showing that 29/33 animal investigations report that OT decreases pain. It is difficult to draw firm conclusions about the effect of OT on pain in humans due to a paucity of methodologically rigorous trials.
Goals / Research Aim: To evaluate the efficacy of intranasal OT as an adjuvant treatment to improve pain and function among men and women with chronic pain.
Methods:
Design: Multi-site, dose-response, placebo-controlled, blinded, sequential, within-subjects crossover trial.
Outcomes: As recommended by the Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials, the primary outcome is change in pain-intensity assessed using the Brief Pain Inventory obtained from daily diaries.
Conditions: Experimental 1: 2-week course of 24-IU intranasal OT administered twice daily. Experimental 2: 2-week course of 48-IU intranasal OT administered twice daily. Control: 2-week course of intranasal placebo. Wash-Out: 2-week period occurring between each condition to allow OT to clear the system.
Recruitment: Patients with chronic neuropathic, musculoskeletal and pelvic pain will be recruited from 3 sites: Vancouver, Calgary, and St. John's. Patients will be randomized to one of 2 sequences (24-IU OT, placebo, 48-IU OT; placebo, 24-IU OT; 48-IU OT). Randomization will be centralized and stratified by site.
Blinding: Patients, researchers, and outcome assessors will be blind to condition.
Sample Size: 336 patients (112 per site) are required to detect a clinically significant (1-point; d = .50) change in pain using covariate adjusted repeated measures design with alpha = .05, power = .80, and one cluster (site).
Expected Outcomes: Provide a definitive answer regarding the efficacy of OT to improve pain and function in chronic pain in humans. An efficacy trial of this nature is a necessary prerequisite to conducting a translation trial which is aimed at improving the uptake and utilization of proven therapies in clinical practice and community settings.
3,227 studies on the registry are indexed under Chronic Pain; 729 are open to participants now.
This study's planned enrollment of 336 is above the median of 60 across 2,388 interventional studies indexed under Chronic Pain.
Browse Chronic Pain studies →Memorial University of Newfoundland is the lead sponsor of 49 studies on the registry; 5 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Inter-Site Inclusion Criteria:
Intra-Site Inclusion Criteria:
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
On an ECG, the QT interval is the time the heart’s lower chambers take to activate electrically and recover in each beat. QTc is that time adjusted for heart rate (QTcF by Fridericia’s formula, QTcB by Bazett’s). Some medicines lengthen it, and a long QTc can raise the risk of a dangerous heart rhythm.
The study may name a correction formula and a limit in milliseconds, often around 450–480.
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Contraception
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
QT and QTc
On an ECG, the QT interval is the time the heart’s lower chambers take to activate electrically and recover in each beat. QTc is that time adjusted for heart rate (QTcF by Fridericia’s formula, QTcB by Bazett’s). Some medicines lengthen it, and a long QTc can raise the risk of a dangerous heart rhythm.
The study may name a correction formula and a limit in milliseconds, often around 450–480.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hypersensitivity
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Patients receive 2-weeks courses of 24-IU oxytocin, placebo, 48-IU oxytocin.
Drug: 24-IU oxytocin · Drug: 48-IU oxytocin · Drug: Placebo
Patients receive 2-weeks courses of placebo, 24-IU oxytocin, 48-IU oxytocin.
Drug: 24-IU oxytocin · Drug: 48-IU oxytocin · Drug: Placebo
Patients will self-administer a 2-week course of 24-IU intranasal oxytocin \[4-IU per puff (12-IU delivered to each nostril); Syntocinon, Novartis, Switzerland\], twice per day (once in the morning and once in the evening).
Patients will self-administer a 2-week course of 48-IU intranasal oxytocin \[4-IU per puff (24-IU delivered to each nostril); Syntocinon, Novartis, Switzerland\], twice per day (once in the morning and once in the evening).
Patients will receive an intranasal placebo containing the same ingredients as the oxytocin nasal spray with the exception of active oxytocin. Administration schedule and procedure will be identical to that described in 24-IU oxytocin.
Pain intensity
Pain severity index on the Brief Pain Inventory - Short Form (BPI-SF). Mean scores range from 0 to 10 with higher scores indicating greater pain.
Time frame: Change from Day 1 to Day 14 of nasal spray administration.
Pain-related interference
Pain interference index on the Brief Pain Inventory - Short Form (BPI-SF). Mean scores range from 0 to 10 with higher scores indicating greater pain-related interference.
Time frame: Change from Day 1 to Day 14 of nasal spray administration.
Emotional function
Depression, Anxiety and Stress scale (DASS). Scores are calculated for 3 subscales that are each composed of 7-items (Depression, Anxiety and Stress). Scores on subscales range between 0 and 21 with higher scores reflecting greater reports of Depression, Anxiety or Stress.
Time frame: Change from Day 1 to Day 14 of nasal spray administration.
Sleep Disturbance
Sleep problems index on the Medical Outcomes Study Sleep Scale
Time frame: Change from Day 1 to Day 14 of nasal spray administration.
Global Impression of Change
Patient Global Impression of Change Scale (PGIC). Scores on this single item measure range between 1 and 7 with higher scores reflecting greater impression of beneficial change.
Time frame: Rated at Day 14 of nasal spray administration
Plan to share: Yes — Individual participant de-identified data (including data dictionaries) will be made available beginning 3-months after final follow-up data has been collected (anticipated September 2024) to researchers who provide a methodologically sound proposal for the purpose of achieving the aims of the approved proposal. Data sharing will be enacted with a data-transfer agreement between the sending and receiving institutions. Proposals should be directed to Joshua Rash (jarash@mun.ca)
Supporting information: Study protocol, Statistical analysis plan, Informed consent form
Time frame: 3-months after final follow-up (anticipated September 2024). Data will remain available for 25-years.
Started Apr 2022 (actual). Primary completion is estimated for Mar 2026, 47 months after the start.
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Memorial University of Newfoundland