Actively Recruiting
A Proof of Principle Study of Ondansetron for the Prevention of Vasovagal Syncope: The Eleventh Prevention of Syncope Trial (POST11)
Led by University of Calgary · Updated on 2024-05-10
70
Participants Needed
1
Research Sites
52 weeks
Total Duration
On this page
AI-Summary
What this Trial Is About
About 20% of adults experience recurrent fainting, leading to significant symptoms, difficulties with work and driving, injuries, and reduced quality of life. Because few treatments have been proven effective in randomized trials, researchers are conducting a phase 2, randomized, double-blind study to test if blocking serotonin 5HT3 receptors with ondansetron can prevent fainting or near fainting caused by tilt-induced vasovagal syncope (VVS). This study aims to provide preliminary data for future larger trials. Participants will be randomly assigned to receive either two doses of ondansetron 8 mg by mouth (one the evening before and one the morning of the study) or matching placebo doses on separate days. After dosing, participants undergo a tilt table test where their heart rhythm, blood pressure, and blood samples will be monitored continuously for up to 60 minutes or until fainting occurs. Additional measurements include bioelectrical impedance to assess fluid shifts in the body during posture changes and questionnaires to evaluate quality of life, anxiety, and depression. During the study, participants will have ECG electrodes and a blood pressure cuff applied, along with an intravenous line for blood sampling. Blood samples will be collected at baseline and during the tilt test to measure catecholamine levels. Participants will also complete online surveys assessing health-related quality of life and mood symptoms. The main outcome is the time until fainting or near fainting within one hour. Secondary outcomes include stroke volume, cardiac output, vascular resistance, and psychological measures monitored during the study and within 12 months. The study lasts about one day for the tilt test and includes follow-up assessments up to one year.
CONDITIONS
Brief Title
A Proof of Principle Study of Ondansetron for the Prevention of Vasovagal Syncope: The Eleventh Prevention of Syncope Trial (POST11)
Who Can Participate
Eligibility Criteria
You may qualify if you...
- At least 1 fainting spell in the year before enrollment
- Score of 2 or more on the Calgary Syncope Symptom Score for vasovagal syncope diagnosis
- Age 18 years or older and able to give informed consent
You will not qualify if you...
- Other causes of fainting such as ventricular tachycardia, complete heart block, orthostatic hypotension, or carotid sinus syndrome
- Unable to provide informed consent
- Significant heart valve, coronary, muscle, conduction problems, or arrhythmia
- Hypertrophic cardiomyopathy
- Having a permanent pacemaker
- Seizure disorder
- High blood pressure over 160/90 mm Hg
- Pregnancy or breastfeeding
- Glaucoma
- Taking medications affecting blood pressure
- Known allergy to ondansetron or related drugs
- Any condition that would prevent completing the study as judged by the investigator
AI-Screening
AI-Powered Screening
Complete this quick 3-step screening to check your eligibility
Your Study Journey
Duration - 2 to 4 weeks
Participants are screened for eligibility to participate in the trial.
1 screening and enrollment visit (in-person)
Duration - 1 day
Participants receive two doses of either ondansetron or a matching placebo, followed by a tilt table test with continuous monitoring and blood sampling to assess the prevention of vasovagal syncope.
1 in-person study visit with multiple assessments including ECG, blood sampling, and questionnaire completion
Duration - Up to 12 months
Participants complete online questionnaires assessing health-related quality of life and anxiety and depression symptoms within 12 months after treatment.
Online questionnaire completion
Trial Site Locations
Total: 1 location
1
University of Calgary
Calgary, Alberta, Canada, T2N 4Z6
Actively Recruiting
How is the study designed?
Study Type
INTERVENTIONAL
Masking
QUADRUPLE
Allocation
RANDOMIZED
Model
PARALLEL
Primary Purpose
TREATMENT
Number of Arms
2
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