A Proof of Principle Study of Ondansetron for the Prevention of Vasovagal Syncope: The Eleventh Prevention of Syncope Trial (POST11)
This study, called POST11, is exploring if a medication called ondansetron can help prevent fainting in people who experience vasovagal syncope (VVS). VVS causes frequent fainting, which can stop people from working or driving, and sometimes cause injuries. Current treatments don't always work well. Researchers will give either ondansetron or a dummy drug (placebo) to 70 participants. They will then observe how these individuals respond to a 'tilt table test', which is a way to safely bring on fainting symptoms in a controlled environment. The main goal is to see if ondansetron reduces the likelihood of feeling faint or actually fainting during this test. The findings could lead to larger studies and potentially a new treatment option for VVS.
At a glance
What is this study about?
Many people regularly experience fainting spells, known as vasovagal syncope (VVS). These fainting episodes can be very disruptive. They might make it difficult to work, drive, or enjoy daily activities, and sometimes even lead to injuries. Because there aren't many really effective treatments for VVS right now, researchers are always looking for new and better ways to help.
This particular study is like a detective trying to solve a puzzle. The researchers believe that a common anti-sickness medication called ondansetron might be able to stop these fainting spells. They're testing this idea because ondansetron works by blocking a specific chemical in the body that they suspect plays a role in VVS.
By carefully comparing ondansetron to a dummy drug (placebo) in a small group of people, they hope to gather important early information. This is called a 'proof-of-concept' study. If ondansetron shows promise in this early stage, it could pave the way for bigger studies in the future, eventually leading to a new and effective treatment option for those living with VVS.
Key takeaways
- Exploring if an anti-sickness drug can prevent fainting.
- Aims to help people with frequent fainting spells (vasovagal syncope).
- Uses a 'tilt table test' to safely check for fainting responses.
- Compares the study drug to a dummy pill (placebo).
- Results could lead to new treatments for fainting.
Who may be eligible?
To be considered for this study, you must be 18 years or older and have experienced at least one fainting spell (syncope) in the last year. You also need to meet specific criteria from a diagnostic score for vasovagal syncope.
However, there are several reasons why you might not be able to join. For example, if your fainting is caused by other heart problems, like an irregular heartbeat or a problem with your heart valves, then this study wouldn't be right for you. People with very high blood pressure, certain eye conditions like glaucoma, or those who are pregnant or breastfeeding also cannot take part.
Additionally, if you're taking medications that could affect your blood pressure, or if you've had an allergic reaction to ondansetron or similar drugs in the past, you likely wouldn't be eligible. The important thing is that the research team wants to make sure the study is safe and appropriate for everyone involved, and that the results are clear.
Could this study suit you?
Answer these quick questions to see if you may be eligible. This is a guide only — the research team makes the final call.
- Are you 18 years old or older?
- Have you fainted at least once in the past year?
- Is your fainting believed to be vasovagal syncope and not another heart problem?
- Are you NOT pregnant or breastfeeding?
- Do you NOT have very high blood pressure or glaucoma?
- Are you NOT allergic to ondansetron or similar medications?
What does participation involve?
If you join this study, you will be randomly assigned to receive either the study drug, ondansetron, or a dummy pill (placebo). You won't know which one you're taking, and neither will the doctors. You'll take two doses: one the evening before your study visit and one on the morning of your visit.
On the morning of your study visit, you'll need to fast (not eat) beforehand, though you can still take your usual medications. The team will attach small devices to you to constantly monitor your heart rhythm and blood pressure, including a cuff on your arm and a special device on your finger. A small needle will be placed in your arm to allow blood samples to be taken throughout the study.
The main part of the study involves a 'tilt table test'. You'll lie flat on a special table, and after a short rest, the table will gently move you to an upright position (about 80 degrees) for up to 60 minutes. During this time, the team will carefully monitor your body's responses, including changes in your blood pressure and heart rate, and collect more blood samples. They will also measure how fluid moves around your body. The study will end if you feel very faint or actually faint, or when the full time has passed. The entire process takes place over one main study day.
Potential risks and benefits
Locations (1)
- University of CalgaryVerified postcodeCalgary, Canada· Recruiting
Common questions
What is vasovagal syncope?
It's a common type of fainting that happens when your body overreacts to certain triggers, causing your heart rate and blood pressure to drop suddenly.
What is ondansetron normally used for?
Ondansetron is a medication commonly used to prevent nausea and vomiting, for example, after surgery or chemotherapy.
What is a 'tilt table test'?
It's a medical test where you lie flat on a table that then slowly tilts you upright. It helps doctors see how your blood pressure and heart rate react to standing up, often to diagnose fainting conditions.
Will I know if I'm getting the real drug or a placebo?
No, this is a 'double-blind' study, meaning neither you nor the research team will know if you're receiving ondansetron or the placebo. This helps make the study fair and scientific.
How long will the study participation last?
Your direct participation will primarily involve one main study day after taking two doses of the study medication.
How to find out more
Always speak to your GP or specialist before deciding to take part in a study.
Interested in taking part?
Discussion
Community discussion
Powered by our forum at community.patient.info. Please be respectful — this is not medical advice.