← Eichor
Study identifier: NCT05755737 Synced from ClinicalTrials.gov · July 28, 2026
● Recruiting

A Proof of Principle Study of Ondansetron for the Prevention of Vasovagal Syncope: The Eleventh Prevention of Syncope Trial (POST11)

Condition: Vasovagal Syncope (VVS) · Syncope  ·  Sponsor: University of Calgary

PhasePhase 2
Planned participants70
Who can joinAll sexes, 18 Years to 100 Years
Healthy volunteersNo

About this study

About 20% of adults faint recurrently. These patients are often highly symptomatic, have problems with employment and driving, can be injured, and have poor quality of life. There are few therapies that have withstood the test of randomized clinical trials. the investigators will conduct a prospective, randomized, parallel, double-blind, proof-of-concept study that tests the hypothesis that serotonin 5HT3 receptor inhibition with ondansetron prevents tilt-induced vasovagal syncope (VVS) and pre-syncope in patients with clinical VVS. A total of 70 patients with quantitative clinical diagnostic criteria for VVS and at least 1 syncopal spell in the preceding year will be randomized in a double-blind acute phase 2 study to ondansetron 8 mg PO BID x 2 doses or matching placebo. The endpoint will be presyncope or syncope associated with diagnostic hemodynamic changes. These data should provide useful preliminary data as a foundation on which to conduct a subsequent randomized clinical trial.

This description comes directly from the study's public registry record.

Talk to the study team

Contact details are listed per location below or on the registry record.

Always discuss trial participation with your own doctor first.

Locations (1)

University of CalgaryCalgary, Alberta, CanadaRecruiting

Follow this study

Get one email when the public record changes — results posted, or the study's status changes. Nothing else, ever.

We email about this public record only. Unsubscribe anytime with one click. Never medical advice.

Is this your study? This page was generated automatically from the public registry record. Sponsors can claim it — free — to add branding and verified contact routing. Claim this page →

This page is independently generated by Eichor from the public ClinicalTrials.gov record and re-synced daily. It is not the sponsor's official website unless claimed. Nothing here is medical advice; eligibility is always determined by the study team — talk to your own doctor first.

Source record: clinicaltrials.gov/study/NCT05755737