Dexamethasone Versus Ondansetron for Preventing Post-Spinal Hypotension in Preeclampsia

August 26, 2026 updated by: Mohamed Amin Abdelhamid Aboughadir, Assiut University

Intravenous Dexamethasone Versus Ondansetron in the Prevention of Post-Spinal Hypotension in Preeclampsia Patients Undergoing Caesarean Delivery: A Prospective Randomized Clinical Trial

This study compares the efficacy and safety of intravenous dexamethasone versus intravenous ondansetron in preventing low blood pressure (hypotension) following spinal anesthesia in pregnant women with preeclampsia undergoing scheduled cesarean delivery.

Spinal anesthesia is the preferred anesthetic method for cesarean delivery, but it frequently causes a sudden drop in maternal blood pressure. In patients with preeclampsia, post-spinal hypotension can compromise blood flow to the placenta and vital organs. While traditional vasopressor medications are used to restore blood pressure, non-adrenergic prophylactic agents such as dexamethasone and ondansetron may help maintain hemodynamic stability through different physiological pathways.

Participants will be randomly assigned to receive either intravenous dexamethasone (8 mg) or intravenous ondansetron (4 mg) 15 minutes prior to the initiation of spinal anesthesia. Blood pressure, heart rate, vasopressor requirements, optic nerve sheath diameter, and maternal and neonatal outcomes will be monitored throughout the surgery and during the immediate postoperative period.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

110

Phase

  • Phase 4

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Pregnant women aged 18 to 40 years.
  • American Society of Anesthesiologists (ASA) physical status III.
  • Diagnosed with preeclampsia (new onset of hypertension ≥140/90 mmHg with proteinuria occurring after 20 weeks of gestation according to ACOG and ISSHP guidelines).
  • Scheduled for elective cesarean delivery under spinal anesthesia.

Exclusion Criteria:

  • Peripartum bleeding.
  • Obesity (body mass index ≥40 kg/m²).
  • Coagulation disorders (platelet count < 75,000/μL).
  • Neurological disorders.
  • Previous or current systemic corticosteroid therapy.
  • Known cardiac disease.
  • History of diabetes mellitus.
  • Renal dysfunction (serum creatinine > 2 mg/dL).
  • Hepatic dysfunction (serum liver enzymes > 2 times the upper limit of normal).
  • Known hypersensitivity to dexamethasone, ondansetron, or any component of the study medications.
  • Emergency cesarean delivery.
  • Known fetal congenital anomalies.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Prevention
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Quadruple

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Group D: Dexamethasone
Patients in Group D will receive intravenous dexamethasone 8 mg diluted with 0.9% normal saline to a total volume of 10 mL, administered slowly over approximately one minute, 15 minutes before the induction of spinal anaesthesia.
Drug: Dexamethasone
Intravenous dexamethasone 8 mg diluted with 0.9% normal saline to a total volume of 10 mL, administered slowly over approximately one minute, 15 minutes before the induction of spinal anesthesia.
Active Comparator: Group O: Ondansetron
Patients in Group O will receive intravenous ondansetron 4 mg diluted with 0.9% normal saline to a total volume of 10 mL, administered slowly over approximately one minute, 15 minutes before the induction of spinal anaesthesia.
Drug: Ondansetron
Intravenous ondansetron 4 mg diluted with 0.9% normal saline to a total volume of 10 mL, administered slowly over approximately one minute, 15 minutes before the induction of spinal anesthesia.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Incidence of post-spinal hypotension
Time Frame: 1 hour
Number of participants with a decrease in systolic blood pressure below 80% of baseline.
1 hour

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Assiut University

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

October 1, 2026

Primary Completion (Estimated)

October 1, 2027

Study Completion (Estimated)

November 1, 2027

Study Registration Dates

First Submitted

August 26, 2026

First Submitted That Met QC Criteria

August 26, 2026

First Posted (Actual)

August 31, 2026

Study Record Updates

Last Update Posted (Actual)

August 31, 2026

Last Update Submitted That Met QC Criteria

August 26, 2026

Last Verified

August 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • Dex vs Ondan: Spinal BP in PE

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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