Apply the PD Model of Peripheral Oxytocin Action to a Multimodal Stimulus

What Was Tested

This registered phase 2 trial tested Oxytocin for chronic pain: fibromyalgia & crps.

This is a study of participants that will receive an intravenous (IV) infusion of oxytocin (naturally occurring hormone that is made in the brain).

Each study participant will have an IV catheter placed.

It had two arms (groups): Oxytocin First, then Placebo (other) and Placebo, Then Oxytocin (other).

Oxytocin administered intravenously for the first half of the study and then will receive intravenous placebo for the second half.

Placebo administered intravenously for the first half of the study and then will receive intravenous oxytocin for the second half.

The registry classes the interventions as drug.

More on the Plan

This is the last of 4 studies to accomplish generation, validation, and application of a PK/PD model for oxytocin in the periphery.

As such, The investigators expect that the effect of oxytocin on pain from this mixed stimulus of heat and vibration will be much more pronounced than that seen with the purely painful stimulus used in previous studies in this series.

This is a double-blind, crossover study in which oxytocin or placebo is infused.

They will come to the Clinical Research Unit and one intravenous catheter (IV) inserted in the forearm for oxytocin or placebo infusion.

Who Took Part

It was open to people of any sex aged from 18 years up to 75 years.

Healthy volunteers could join, not only people with the condition.

Examples of who could join: Male or female \> 18 and \< 75 years of age, Body Mass Index (BMI) \<40.

The full record lists 4 inclusion and 4 exclusion criteria; among the exclusions: subjects with neuropathy, chronic pain, diabetes mellitus, or taking benzodiazepines or pain medications on a daily basis.

How the Study Was Run

The set-up was randomized, crossover and triple-blind.

Random assignment meant chance, not the researchers, decided who got Oxytocin and who got the comparison, which limits bias.

In the crossover set-up each of the chronic pain: fibromyalgia & crps participants took both Oxytocin and the comparison in turn, acting as their own control.

Blinding on both sides kept the chronic pain: fibromyalgia & crps participants and researchers unaware of who received Oxytocin.

Those kept unaware of assignments: participant, investigator and outcomes assessor.

It started in 2025-01 with completion listed for 2025-12.

It ran at 1 site in United States.

Its stated primary purpose is basic science.

What Was Measured

The main thing measured (primary outcome): Heat pain with vibration (time frame: Baseline before infusion). Heat pain with vibration (time frame: 5 minutes post infusion initiation). Heat pain with vibration (time frame: 15 minutes post infusion initiation).

It also tracked 4 secondary outcomes, for example Heat pain without vibration, Heat pain without vibration, Heat pain without vibration and Heat pain without vibration.

What This Means in Plain Language

Put simply, this is a phase 2, randomized trial of Oxytocin in people with chronic pain: fibromyalgia & crps.

It was withdrawn before enrolling anyone; no results are posted to the registry yet, so nothing here describes outcomes.

More context: the Oxytocin compound page, Chronic pain: fibromyalgia & CRPS research.