The Relaxant Effect of Nitroglycerin on Oxytocin Desensitized Human Myometrium

What Was Tested

The trial (not phased) is built around Oxytocin.

Oxytocin causes myometrial contraction via the oxytocin receptor (OTR).

It had four arms (groups): Control group (no intervention), Oxytocin desensitized - no nitroglycerin (active comparator), Oxytocin desensitized - plus nitroglycerin (active comparator) and Non oxytocin desensitized - plus nitroglycerin (active comparator).

No oxytocin desensitization (pretreatment), no nitroglycerin.

Pretreated with oxytocin, no nitroglycerin exposure.

Pretreated with oxytocin followed by nitroglycerin exposure.

The registry classes the interventions as drug.

More on the Plan

Oxytocin and nitroglycerin have opposing actions on the myometrium.

The situation where a difficult fetal extraction is encountered at cesarean section may be in two broad groups of patients.

Those pre-exposed to oxytocin and those with an oxytocin naïve myometrium.

Given the large observational variation in dosages of nitroglycerin usage seen in the literature the researchers feel it is vital to investigate whether pre-exposure to oxytocin impacts on the ability of nitroglycerin to relax uterine smooth muscle.

Who Took Part

The registry lists 17 actual participants took part.

It was open to women only aged from 16 years up to 40 years.

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

Examples of who could join: Patients who give written consent to participate in this study. Patients with gestational age 37-41 weeks. Non-laboring patients, not exposed to exogenous oxytocin. Patients requiring primary Cesarean delivery or first repeat Cesarean delivery under spinal anesthesia.

The full record lists 4 inclusion and 6 exclusion criteria; among the exclusions: patients who refuse to give written informed consent; patients who require general anesthesia; patients who had previous uterine surgery or more than one previous cesarean delivery.

How the Study Was Run

Design: non-randomized, parallel-group and open-label.

Groups ran in parallel: each of the participants stayed in one arm throughout.

Everyone knew when Oxytocin was being given (open label), which is simpler to run but leaves more room for expectations to affect what is reported.

It started in 2018-01-03 with completion listed for 2018-04-13.

It ran at 1 site in Canada.

Its stated primary purpose is treatment.

What Was Measured

The main thing measured (primary outcome): Motility Index (time frame: 8 hours).

It also tracked 3 secondary outcomes, for example Amplitude of contraction, Frequency of contraction and Integrated area under response curve (AUC).

What This Means in Plain Language

Put simply, this is a not phased, non-randomized trial of Oxytocin in 17 people.

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

The trial is marked completed; no results are posted to the registry yet, so nothing here describes outcomes.

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