Effect of Prophylactic Intravenous Ondansetron 4 mg on Maternal Hypotension, Bradycardia and Atropine Requirement During Spinal Anesthesia for Elective Cesarean Section: a Randomized, Double-blind, Placebo-controlled Trial
Sponsor study identifier
Secondary identifiers
REGISTRY · Aydin Adnan Menderes University Faculty of Medicine Clinical Research Ethics Committee
interventional
66
1 country
1
Study Start
April 16, 2021
Actual (reported)Primary Completion
April 16, 2022
Actual (reported)Study Completion
April 16, 2022
Actual (reported)Spinal anesthesia is the preferred technique for elective cesarean section, but it is frequently complicated by maternal hypotension and bradycardia. Activation of serotonin type 3 (5-hydroxytryptamine type 3; 5-HT3) receptors on cardiac vagal afferent nerves has been proposed as one mechanism of the Bezold-Jarisch reflex, which may contribute to sudden bradycardia and vasodilation after spinal anesthesia. Ondansetron is a selective 5-HT3 receptor antagonist. This randomized, double-blind, placebo-controlled trial evaluated whether a single intravenous (IV) dose of ondansetron 4 mg given 5 minutes before spinal anesthesia reduces maternal hypotension, bradycardia and the need for rescue medications (ephedrine and atropine) in women undergoing elective cesarean section. Hemodynamic variables and the pulse oximetry-derived perfusion index (PI) and pleth variability index (PVI) were recorded at predefined time points, including during a passive leg raising (PLR) maneuver before spinal anesthesia.
Registry-reported information. Elapsed time and enrollment totals alone do not measure study progress or recruitment pace.
April 16, 2022
Actual (reported)Click on a node to explore related trials.
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Dates and qualifiers reported by the registry. Estimated dates do not confirm that a milestone has occurred.
April 16, 2021
Actual (reported)April 16, 2022
Actual (reported)April 16, 2022
Actual (reported)October 13, 2026
Actual (reported)October 20, 2026
Actual (reported)Incidence of maternal hypotension
Number of participants with hypotension, defined as a decrease in systolic blood pressure to less than 80% of the baseline value.
From spinal anaesthesia to 15 minutes after spinal anaesthesia
Atropine requirement
From spinal anaesthesia to the end of surgery
Incidence of bradycardia
From spinal anaesthesia to 15 minutes after spinal anaesthesia
Participants received 2 milliliters (mL) of 0.9% sodium chloride intravenously (IV) 5 minutes before spinal anesthesia.
Participants received ondansetron 4 milligrams (mg) in 2 milliliters (mL) intravenously (IV) 5 minutes before spinal anesthesia.
A single intravenous (IV) dose of ondansetron 4 milligrams (mg) in 2 milliliters (mL), administered 5 minutes before spinal anesthesia.
A single intravenous (IV) dose of 2 milliliters (mL) of 0.9% sodium chloride, administered 5 minutes before spinal anesthesia in a syringe identical in appearance to the active drug.
Aydin Adnan Menderes University Hospital, Department of Anaesthesiology and Reanimation
Aydin, EFELER, 09004, Turkey (Türkiye)
Sahoo T, SenDasgupta C, Goswami A, Hazra A. Reduction in spinal-induced hypotension with ondansetron in parturients undergoing caesarean section: a double-blind randomised, placebo-controlled study. Int J Obstet Anesth. 2012 Jan;21(1):24-8. doi: 10.1016/j.ijoa.2011.08.002. Epub 2011 Nov 18.
66 participants (actual enrollment reported by the registry).
First Submitted
October 13, 2026
First Posted
October 20, 2026
Total ephedrine dose
From spinal anaesthesia to the end of surgery
Systolic blood pressure
Baseline, during passive leg raising, 1, 5, 8, 12 and 15 minutes after spinal anaesthesia, and after delivery
Heart rate
Baseline, during passive leg raising, 1, 5, 8, 12 and 15 minutes after spinal anaesthesia, and after delivery
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Study Start
April 16, 2021
Actual (reported)Primary Completion
April 16, 2022
Actual (reported)Study Completion
April 16, 2022
Actual (reported)Last Updated
October 23, 2026
Record last verified: 2026-10
De-identified individual participant data underlying the results reported in the published article (baseline characteristics, hemodynamic measurements, rescue medication use and neonatal Apgar scores) will be shared.
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Source: ClinicalTrials.gov.
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