RecruitingPhase 2

Oxytocin Pharmacokinetics and Pharmacodynamics

United States100 participantsStarted 2025-01-01

Plain-language summary

Oxytocin is the first-line drug to promote contraction of the uterus and prevent atony immediately after delivery. Nonetheless, unpredictable uterine atony refractory to oxytocin affects roughly 250,000 parturients annually in the U.S. and rates are increasing. This two-part study will measure the action of oxytocin at cesarean delivery. The first part will measure the pharmacokinetics of a single intravenous (IV) dose of deuterium-labeled oxytocin. The second part will measure the pharmacodynamics of all plasma oxytocin to see how concentrations correspond to the contractile effect on the uterus. After delivery of the fetus, study subjects will receive a bolus of IV deuterated oxytocin followed by an unlabeled oxytocin infusion. Venous blood samples drawn at multiple time points (within 1 hour after delivery) will be analyzed for plasma concentrations of labeled and unlabeled (endogenous + exogenous infused) oxytocin over time. Plasma concentrations will be compared with 0-10 uterine tone scores measuring uterine contraction strength, to describe the concentration-effect relationship. The goal of this study is to define both the pharmacokinetics and pharmacodynamics of oxytocin in parturients to help identify the cause(s) of failed first-line oxytocin therapy.

Who can participate

Age range

18 Years – 50 Years

Sex

FEMALE

See this in plain English?

AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.

Inclusion Criteria * 18-50 years old * intrauterine pregnancy * term (\>39 weeks gestation or 37-39 weeks gestation with fetal or maternal medical indication for delivery) pregnancy * non-emergent (scheduled or unscheduled) cesarean delivery Exclusion Criteria: * allergy or contraindication to oxytocin * inability to provide informed consent

Questions worth asking your doctor

Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.

1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?

Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.

Questions for the trial coordinator

The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.

1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?

A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.

What they're measuring

Baseline plasma concentrations of deuterated oxytocin

Timeframe: Intraoperatively (prior to delivery)

Plasma concentrations of deuterated oxytocin at 1 minute

Timeframe: Intraoperatively (1 minute following study drug administration)

Plasma concentrations of deuterated oxytocin at 2.5 minutes

Timeframe: Intraoperatively (2.5 minutes following study drug administration)

Plasma concentrations of deuterated oxytocin at 5 minutes

Timeframe: Intraoperatively (5 minutes following study drug administration)

Plasma concentrations of deuterated oxytocin at 10 minutes

Timeframe: Intraoperatively (10 minutes following study drug administration)

Plasma concentrations of deuterated oxytocin at 15 minutes

Timeframe: Intraoperatively (15 minutes following study drug administration)

Plasma concentrations of deuterated oxytocin at 20 minutes

Trial details

NCT IDNCT05488457

SponsorUniversity of Chicago

Sponsor typeOTHER

Study typeINTERVENTIONAL

Primary completion2026-09-30

Contact for this trial

Naida M Cole, MD

773-702-6700 nmcole@bsd.uchicago.edu

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