Recruiting
Phase 2

Ondansetron

Sponsor:

University of Calgary

Code:

NCT05755737

Conditions

Vasovagal Syncope (VVS)

Syncope

Eligibility Criteria

Sex: All

Age: 18 - 70+

Healthy Volunteers: Not accepted

Interventions

Ondansetron

Placebo

Study Details

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

Study ID

NCT05755737

Start date

Jun 1, 2023

Status verified date

May, 2024

Completion date

Dec 31, 2026

Anticipated

Primary completion date

Dec 31, 2025

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18 - 70+

Healthy Volunteers: Not accepted

Inclusion Criteria:

(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

Exclusion Criteria:

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

Study Design

Enrollment

70 participants

Anticipated

Allocation

Randomized

Intervention Model

Parallel Assignment

Primary purpose

Treatment

Interventions and Outcome Measures

Arms

active comparator: Ondansetron

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

active comparator: Placebo

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

Interventions

Ondansetron

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

Placebo

Matching placebo identical in appearance.

Primary outcome measure

  • Time to syncope or presyncope [ Time Frame: 1 hour ]

Central Contacts and Locations

Locations

University of Calgary

Recruiting

Calgary, Alberta, Canada, T2N 4Z6

Contacts

Robert S Sheldon, MD, PhD

403-220-8191sheldon@ucalgary.ca

Principal Investigator:

Robert Sheldon, MD

More Information

Sponsor

University of Calgary

Last update posted

May 10, 2024

Last verified

May, 2024

Keywords

  • Ondansetron

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by University of Calgary on 2024-05-10.