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

Recruiting now · Phase 2 · Has a placebo group

Conditions studied: Vasovagal Syncope (VVS), Syncope

In brief

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.

Key facts

Study ID

NCT05755737

Run by

University of Calgary

People needed

70

Starts

2023-06-01

Expected to finish

2026-12-31

Last updated by the study team

2024-05-10

Who can join

Age: 18 and older, up to 100. Sex: any. Healthy volunteers: not accepted.

You may qualify if…

• (A) ≥1 syncopal spells in the year preceding enrolment (B) ≥-2 points on the Calgary Syncope Symptom Score( Accurate Calculation for Diagnosis of Vasovagal Syncope) (C) Age ≥18 years with informed consent

You may not qualify if…

• other causes of syncope, such as ventricular tachycardia, complete heart block, orthostatic hypotension or hypersensitive carotid sinus syndrome
• an inability to give informed consent
• important valvular, coronary, myocardial or conduction abnormality or significant arrhythmia
• hypertrophic cardiomyopathy
• a permanent pacemaker
• a seizure disorder
• hypertension defined as >160/90 mm Hg
• pregnancy
• lactating women
• glaucoma
• medications with known effects on BP
• Known hypersensitivity to ondansetron and related medications
• other factors which, in the investigator's opinion, would prevent the subject from completing the protocol.

Where it is running

• University of Calgary — Calgary, Alberta, Canada (enrolling)

Full record on ClinicalTrials.gov

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