Magnesium Sulfate in Obese Preeclamptics

Randomized Trial of Magnesium Sulfate in Obese Preeclamptic Women

The purpose of this study is to learn how medications participant will receive in the course of their delivery are metabolized (broken down by the body). The investigators hope to learn more about the way drugs are metabolized by pregnant women, and how those drugs are distributed in the blood and body compartments and cleared in the urine, and how maternal body weight affects the metabolism. With this information the investigators will be able to develop a treatment regimen considering factors in the body that affect magnesium levels so that the investigators can improve treatment of pregnant women. The goal of the study is to understand how different dosing of magnesium sulfate affects blood levels of the magnesium in larger women.

Study Overview

• Status: Completed
• Conditions: Preeclampsia
• Intervention / Treatment: Drug: Magnesium sulfate 4g loading dose, 1g/hr infusion; Drug: Magnesium sulfate 6g loading dose, 2g/hr infusion

Detailed Description

The purpose of this study is to learn how medications participant will receive in the course of their delivery are metabolized (broken down by the body). The investigators hope to learn more about the way drugs are metabolized by pregnant women, and how those drugs are distributed in the blood and body compartments and cleared in the urine, and how maternal body weight affects the metabolism. With this information the investigators will be able to develop a treatment regimen considering factors in the body that affect magnesium levels so that the investigators can improve treatment of pregnant women. The goal of the study is to understand how different dosing of magnesium sulfate affects blood levels of the magnesium in larger women.

Magnesium sulfate is generally given to patients to protect the mother against seizures in the case of preeclampsia. Different hospitals in the United States use different doses of magnesium sulfate. Participants will receive one of two accepted doses of magnesium sulfate for preeclampsia. The dose is usually 4g - 6g at the start, with another dose of 2-3 g every hour until 24 hours after delivery. Participants will be assigned to either a dose of 4 g at the start, followed by 1g every hour; or a dose of 6 g at the start, followed by 2g every hour until treatment for preeclampsia is complete. Participants will receive magnesium sulfate in the course of their normal clinical care whether or not they participate in this study.

• Study Type: Interventional
• Enrollment (Actual): 66
• Phase: Phase 4

Contacts and Locations

Study Locations

• United States
  • Oregon
    • Portland, Oregon, United States, 97239
      • Oregon Health & Science Univerity

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 45 years (Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: Female

Description

Inclusion Criteria:

• Pregnant women who are ages 18-45
• 32-42 weeks' pregnant
• Prescribed magnesium sulfate for preeclampsia
• BMI ≥35 kg/m2

Exclusion Criteria:

• Pregnant women < 32 weeks' pregnant
• Women who are on dialysis

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: MgSO4 4g load, 1g/hr infusion; Once their obstetrician prescribes magnesium sulfate, participant will be assigned by 50/50 chance to one of two treatment regimens. Participant will be assigned to either a dose of 4 g at the start, followed by 1g every hour; or a dose of 6 g at the start, followed by 2g every hour until treatment for preeclampsia is complete.	Drug: Magnesium sulfate 4g loading dose, 1g/hr infusion
Experimental: MgSO4 6g load, 2g/hr infusion; Once their obstetrician prescribes magnesium sulfate, participant will be assigned by 50/50 chance to one of two treatment regimens. Participant will be assigned to either a dose of 4 g at the start, followed by 1g every hour; or a dose of 6 g at the start, followed by 2g every hour until treatment for preeclampsia is complete.	Drug: Magnesium sulfate 6g loading dose, 2g/hr infusion

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Maternal Serum Magnesium Level at 4 Hours After Administration	magnesium level in mg/dL	4 hours

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Maternal Serum Magnesium Level at Time of Delivery	magnesium level in mg/dL	Within 20 minutes of delivery
Maternal Side Effects	Presence or absence of the following: flushing, lethargy, palpitations, pain at IV site, respiratory depression	4 hours

Collaborators and Investigators

• Sponsor: Oregon Health and Science University
• Investigators: Principal Investigator: Kathleen Brookfield, M.D., PhD, Oregon Health and Science University

Publications and helpful links

General Publications

• Brookfield KF, Tuel K, Rincon M, Vinson A, Caughey AB, Carvalho B. Alternate Dosing Protocol for Magnesium Sulfate in Obese Women With Preeclampsia: A Randomized Controlled Trial. Obstet Gynecol. 2020 Dec;136(6):1190-1194. doi: 10.1097/AOG.0000000000004137.

Study record dates

Study Major Dates

• Study Start (Actual): July 12, 2016
• Primary Completion (Actual): June 30, 2019
• Study Completion (Actual): June 30, 2019

Study Registration Dates

• First Submitted: July 7, 2016
• First Submitted That Met QC Criteria: July 13, 2016
• First Posted (Estimate): July 18, 2016

Study Record Updates

• Last Update Posted (Actual): May 13, 2020
• Last Update Submitted That Met QC Criteria: May 4, 2020
• Last Verified: May 1, 2020

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Pregnancy Complications; Hypertension, Pregnancy-Induced; Pre-Eclampsia; Physiological Effects of Drugs; Molecular Mechanisms of Pharmacological Action; Anti-Arrhythmia Agents; Central Nervous System Depressants; Peripheral Nervous System Agents; Analgesics; Sensory System Agents; Anesthetics; Membrane Transport Modulators; Anticonvulsants; Calcium-Regulating Hormones and Agents; Reproductive Control Agents; Calcium Channel Blockers; Tocolytic Agents; Magnesium Sulfate
• Other Study ID Numbers: OHSU IRB 15809

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: No

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No