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

NCT05755737 | Recruiting Phase 2

• 1 other identifier: POST 11
• Study Type: interventional
• Target: 70
• Locations: 1 country
• Sites: 1

Brief Summary

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.

Conditions

Vasovagal Syncope (VVS); Syncope

Keywords

Ondansetron

Outcome Measures

Primary Outcomes (1)

• Time to syncope or presyncope

  1 hour

Secondary Outcomes (6)

• stroke volume

  1 hour

• cardiac output

  1 hour

• catecholamine levels

  1 hour

• Hospital Anxiety and Depression Scale (HADS)

  Within 12 months period of the study

• RAND-36

  Within 12 months period of the study

Study Arms (2)

Ondansetron

ACTIVE COMPARATOR

2 doses of Ondansetron 8mg PO (evening before and morning of study)

Drug: Ondansetron

Placebo

ACTIVE COMPARATOR

2 doses of matching placebo 8 mg PO (evening before and morning of study)

Drug: Placebo

Interventions

Ondansetron DRUG

Serotonin antagonists (5-HT3 antagonists) (Carbazole Derivative)

Ondansetron

Placebo DRUG

Matching placebo identical in appearance.

Placebo

Eligibility Criteria

• Age: 18 Years - 100 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

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.

Sponsors & Collaborators

• University of Calgary: lead

Study Sites (1)

University of Calgary

Calgary, Alberta, T2N 4Z6, Canada

RECRUITING

MeSH Terms

Conditions

Syncope, Vasovagal; Syncope

Interventions

Ondansetron

Condition Hierarchy (Ancestors)

Orthostatic Intolerance; Primary Dysautonomias; Autonomic Nervous System Diseases; Nervous System Diseases; Unconsciousness; Consciousness Disorders; Neurobehavioral Manifestations; Neurologic Manifestations; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Intervention Hierarchy (Ancestors)

Imidazoles; Azoles; Heterocyclic Compounds, 1-Ring; Heterocyclic Compounds; Carbazoles; Indoles; Heterocyclic Compounds, 2-Ring; Heterocyclic Compounds, Fused-Ring; Heterocyclic Compounds, 3-Ring

Study Design

• Study Type: interventional
• Phase: phase 2
• Allocation: RANDOMIZED
• Masking: QUADRUPLE
• Who Masked: PARTICIPANT, CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: February 9, 2023
• First Posted: March 6, 2023
• Study Start: June 1, 2023
• Primary Completion: December 31, 2025
• Study Completion (Estimated): December 31, 2026
• Last Updated: May 10, 2024

Record last verified: 2024-05

Data Sharing

• IPD Sharing: Will not share

Locations

CA (1)