Clinical trial NCT03898882: Pharmacokinetics of Oxytocin at Cesarean Delivery
Official title: The Pharmacokinetics of Oxytocin in Pregnant Women Undergoing Cesarean Delivery - a Feasibility Pilot Study
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Postpartum Hemorrhage
Lead sponsor: Washington University School of Medicine
Sponsor class: OTHER
First posted: 2019-04-02
Enrollment: 30
Sex: FEMALE
Minimum age (years): 18
Maximum age (years): 45
Standard ages: ADULT
Accepts healthy volunteers: yes
Observational model: COHORT
Time perspective: PROSPECTIVE
Sampling method: NON_PROBABILITY_SAMPLE
Study population: Pregnant women scheduled for cesarean delivery of their babies at term

Brief summary: The primary objective is to obtain data to inform the design of a population pharmacokinetic study of oxytocin after administration at CD as per standard institutional practice.

Detailed description: In this pilot study the investigators will compare plasma oxytocin concentrations measured in arterial and venous blood, after oxytocin administration at cesarean delivery, in order to assess the validity of venous samples. They will also measure oxytocinase to explore how levels vary around the time of delivery of the placenta and to assess the effect that this may have on the metabolism of oxytocin.

Eligibility criteria: Inclusion Criteria:

* Term singleton pregnancy
* Age 18-45 years of age
* ASA classification 2 or 3
* Scheduled cesarean delivery under neuraxial anaesthesia

Exclusion Criteria:

* Age or ASA classification outside of inclusion criteria
* Need for general anaesthesia
* Absence of consent
* Inability to communicate in English or other barrier to providing informed consent

Primary outcomes:
measure: Arterial [OXT]
timeFrame: Scheduled samples during the first 30 minutes after oxytocin administration
measure: Venous [OXT]
timeFrame: Scheduled samples during the first 30 minutes after oxytocin administration
Secondary outcomes:
measure: Arterial [OXTase]
timeFrame: Scheduled samples during the first 30 minutes after oxytocin administration
measure: Uterine tone
timeFrame: Scheduled measurements during the first 30 minutes after oxytocin administration
measure: Hypotension
timeFrame: Measured intraoperatively
measure: Nausea & Vomiting
timeFrame: Recorded intraoperatively
measure: EBL
timeFrame: Estimated at the end of surgery
Other outcomes:
Locations:
city: Saint Louis
country: United States
facility: Washington University in St. Louis
state: Missouri
Study officials:
affiliation: Washington University School of Medicine
name: David T Monks, MBChB
role: PRINCIPAL_INVESTIGATOR
References:
citation: Say L, Chou D, Gemmill A, Tuncalp O, Moller AB, Daniels J, Gulmezoglu AM, Temmerman M, Alkema L. Global causes of maternal death: a WHO systematic analysis. Lancet Glob Health. 2014 Jun;2(6):e323-33. doi: 10.1016/S2214-109X(14)70227-X. Epub 2014 May 5.
citation: Attilakos G, Psaroudakis D, Ash J, Buchanan R, Winter C, Donald F, Hunt LP, Draycott T. Carbetocin versus oxytocin for the prevention of postpartum haemorrhage following caesarean section: the results of a double-blind randomised trial. BJOG. 2010 Jul;117(8):929-36. doi: 10.1111/j.1471-0528.2010.02585.x. Epub 2010 May 19.
citation: Chiou WL. The phenomenon and rationale of marked dependence of drug concentration on blood sampling site. Implications in pharmacokinetics, pharmacodynamics, toxicology and therapeutics (Part II). Clin Pharmacokinet. 1989 Oct;17(4):275-90. doi: 10.2165/00003088-198917040-00005. No abstract available.
citation: Chiou WL. The phenomenon and rationale of marked dependence of drug concentration on blood sampling site. Implications in pharmacokinetics, pharmacodynamics, toxicology and therapeutics (Part I). Clin Pharmacokinet. 1989 Sep;17(3):175-99. doi: 10.2165/00003088-198917030-00004.