Efficacy of Spinal Oxytocin in Healthy Volunteers

What Was Tested

The trial (phase 2) is built around Oxytocin.

The purpose of this study is to determine the effect of intrathecal oxytocin on areas and intensity of hyperalgesia and allodynia induced by topical capsaicin.

It had three arms (groups): one (experimental), one (experimental) and Placebo (active comparator).

Preservative free normal saline injected spinally.

The registry classes the interventions as drug.

More on the Plan

Purpose: There is a strong experimental basis to support the study of oxytocin by the spinal route for analgesia in humans.

Oxytocin containing cells in the dorsal parvocellular division of the paraventricular nucleus (PVN) project to the spinal cord (1).

Noxious stimulation activates these cells via the A1 noradrenergic relay in the pons (2) and produces analgesia by spinal release of oxytocin, since intrathecal injection of an oxytocin receptor antagonist worsens pain behaviors from peripheral inflammation (3).

Objectives: Determine the effect of intrathecal oxytocin on areas and intensity of hyperalgesia and allodynia induced by topical capsaicin.

Who Took Part

20 actual participants took part.

It was open to people of any sex aged from 18 years up to 59 years.

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

Examples of who could join: Weight \< 240 pounds. American Society of Anesthesiology Category 1 or 2.

The full record lists 3 inclusion and 6 exclusion criteria; among the exclusions: allergy to oxytocin or lidocaine; allergy to chilli peppers; females: active gynecological disease such as uterine fibroids or ongoing bleeding.

How the Study Was Run

Design: randomized, parallel-group and triple-blind.

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

The Oxytocin group and the comparison group ran side by side rather than switching.

As a double-blind Oxytocin study, the assignments were hidden from both participants and investigators until the end.

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

It started in 2014-01-02 with completion listed for 2022-10-10.

It ran at 1 site in United States.

Its stated primary purpose is basic science.

What Was Measured

Primary outcome: Hyperalgesia (time frame: 105 minutes after study drug injection).

What This Means in Plain Language

Put simply, this is a phase 2, randomized trial of Oxytocin in 20 people.

Its size is small, so on its own it can only give an early look.

It ended early (terminated); results are posted on the registry, and this page does not restate them.

More context: the Oxytocin compound page, all human trials.