A Phase 2 interventional study of Ondansetron and Placebo in Vasovagal Syncope (VVS) and Syncope, sponsored by University of Calgary. Recruiting at 1 site in Canada. Open to participants aged 18 Years to 100 Years. Per ClinicalTrials.gov, last updated 2024-05-10.
Sponsored by University of Calgary · Phase 2, Interventional, and Treatment
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 will be a randomized, double-blind, parallel-arm study in which the subjects will undergo a tilt table test following 2 doses of ondansetron 8 mg PO (evening before and morning of study) or after 2 doses of matching placebo (on separate days). On the morning of the study, the fasting subject (except for medications) will be instrumented, on an empty bladder. ECG electrodes will be applied to monitor continuous heart rhythm. BP will be monitored continuously using a finger volume clamp method using one or more of several extant devices, and calibrated with intermittent brachial cuff measurements. One intravenous cannula will be placed in the contralateral arm (to the BP cuff) for blood sampling.
3.9. Tilt Table Protocol: Following the insertion of the venous cannulae, a period of at least 20 minutes will be allowed to elapse before a 10-minute basal control (baseline) period. Baseline data will be digitally recorded in this time. In the last 5 minutes of this period, blood will be drawn for fractionated plasma catecholamines. The table will be rapidly raised to 80 degrees for up to 60 minutes. The Investigators are avoiding tilt test methods with provocative medications to avoid the issue of multiple causal factors. At 10 minutes and 30 minutes following onset of tilt (or at the onset of severe presyncope or hypotension [systolic BP \<70 mmHg]), venous fractionated catecholamines will be sampled. The study will be terminated if the subject develops syncope or at the completion of the protocol.
3.10. Assessment of Central Volume Changes with Upright Posture: Segmental bioelectrical impedance (BEI) will measure fluid shifts through the study to determine central volume changes with upright posture and in response to changing levels of CO2. The fluid content in the upper torso (chest), the lower torso (abdominal), thigh, and calf will be assessed. BEI is measured by passing a small current between electrodes and measuring the impedance with voltage-sensing electrodes to determine fluid content in four regions of the body . Body segment volume is inversely proportional to electrical resistance (V\~1/R), so an increase in resistance reflects a loss of body fluid.
3.11. Questionnaires: A brief online questionnaire will be administered to the patients to get a metric of their health-related quality of life (RAND-36), and anxiety and depression symptoms (HADS). This will be administered through RedCap Survey.
88 studies on the registry are indexed under Syncope, Vasovagal; 28 are open to participants now.
This study's planned enrollment of 70 is above the median of 59 across 58 interventional studies indexed under Syncope, Vasovagal.
Browse Syncope, Vasovagal studies →University of Calgary is the lead sponsor of 703 studies on the registry; 196 are open to participants now.
Of its 10 completed or terminated interventional studies of FDA-regulated products, 2 (20%) have results posted.
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Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
(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
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hypersensitivity
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
2 doses of Ondansetron 8mg PO (evening before and morning of study)
Drug: Ondansetron
2 doses of matching placebo 8 mg PO (evening before and morning of study)
Drug: Placebo
Serotonin antagonists (5-HT3 antagonists) (Carbazole Derivative)
Matching placebo identical in appearance.
Time to syncope or presyncope
Time frame: 1 hour
stroke volume
Time frame: 1 hour
cardiac output
Heart Rate \* Stroke volume, and it will be measured using Beat -To Beat BP measurement and HR measurement
Time frame: 1 hour
catecholamine levels
Time frame: 1 hour
Hospital Anxiety and Depression Scale (HADS)
The total score is out of 42, (21 per subscale). Scores are derived by summing responses for each of the two subscales or for the scale as a whole Higher scores indicate greater levels of anxiety or depression. The total HADS score may be regarded as a global measure of psychological distress
Time frame: Within 12 months period of the study
RAND-36
The RAND 36-Item Health Survey (Version 1.0) taps eight health concepts: physical functioning, bodily pain, role limitations due to physical health problems, role limitations due to personal or emotional problems, emotional well-being, social functioning, energy/fatigue, and general health perceptions. All questions are scored on a scale from 0 to 100, with 100 representing the highest level of functioning possible. Aggregate scores are compiled as a percentage of the total points possible, using the RAND scoring table
Time frame: Within 12 months period of the study
systemic vascular resistance
it will be measured using Beat -To Beat BP measurement
Time frame: 1 hour
Plan to share: No
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Studies of the drug tested here: Ondansetron