SYNERGY OSA - EFFICACY, SAFETY and TOLERABILITY OF COMBINED THERAPY WITH A SOMNOMED ORAL APPLIANCE AND THE CARBONIC ANHYDRASE INHIBITOR SULTHIAME IN PATIENTS WITH OBSTRUCTIVE SLEEP APNEA. A Randomized, Double-Blind, Placebo Controlled, Proof-of-Concept Trial
Obstructive sleep apnoea is a common condition where the airway narrows or closes during sleep, causing snoring and frequent breathing pauses. Many people use a custom-made mouthguard (oral appliance) to hold their jaw forward at night. However, for some, this splint does not completely stop breathing pauses. This clinical trial looks at whether adding a medicine called sulthiame can help. Sulthiame works by gently stimulating normal breathing reflexes during sleep. Adults taking part will continue wearing their mouth splint while testing both sulthiame tablets and dummy tablets (placebos) for two weeks each in a random order. Doctors will measure overnight oxygen levels, sleep quality, and daytime alertness to see if the combined treatment works better than the splint alone. The goal is to discover new, effective options for people who need extra support managing their sleep apnoea.
At a glance
What is this study about?
Obstructive sleep apnoea (OSA) happens when the muscles in the throat relax too much during sleep. This blocks the airway, causing breathing to stop and start repeatedly through the night. Over time, poor sleep can lead to severe tiredness, low mood, and higher risks of heart problems. While continuous positive airway pressure (CPAP) machines are widely used, many people prefer wearing a custom mouthguard (an oral appliance) that keeps the lower jaw forward to keep the throat open.
For some people, a mouthguard helps but does not completely solve the problem. They may still experience interrupted sleep and low oxygen levels. This trial is investigating whether adding a medication called sulthiame to an oral appliance can provide better relief. Sulthiame is a tablet that targets specific chemical signals in the body, helping the brain regulate breathing more steadily during sleep.
In this study, researchers want to see if combining the mouth splint with sulthiame lowers the number of breathing pauses more effectively than using the splint with a dummy pill (placebo). Because this is a 'proof-of-concept' trial, it aims to show whether this combination is safe, comfortable, and genuinely helpful before larger studies begin.
Key takeaways
- Tests a combined approach using a mouth splint and a tablet called sulthiame for sleep apnoea.
- Aimed at adults whose sleep apnoea is not fully controlled by a dental device alone.
- Uses a cross-over design, meaning all participants receive both the medicine and a dummy pill at different times.
- Involves overnight sleep studies to measure breathing, oxygen levels, and sleep quality.
- Participation is voluntary and closely supervised by medical specialists.
Who may be eligible?
This trial is open to adults aged 18 and over who have been diagnosed with obstructive sleep apnoea. To take part, you must already be using an oral appliance (a custom dental splint) to treat your condition.
You may be suitable if your mouthguard is not fully controlling your symptoms. In medical terms, this means you still have at least 15 breathing pauses or shallow breaths per hour of sleep while wearing your splint.
People with certain medical conditions, those who are pregnant or breastfeeding, or anyone taking medicines that interact with sulthiame may not be able to join. The study team will run simple health checks to make sure the trial is safe for you.
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.
- I am aged 18 or older.
- I have been diagnosed with obstructive sleep apnoea.
- I currently use a custom mouthguard (oral appliance) for sleep apnoea.
- My sleep apnoea symptoms (such as snoring or waking up tired) persist despite using my device.
- I am willing to attend overnight sleep tests and take study tablets as instructed.
What does participation involve?
Taking part involves several visits to a hospital or sleep clinic over a few weeks. Because this is a 'cross-over' trial, every participant gets to try both the active medicine (sulthiame) and the dummy pill (placebo) at different times for two weeks each, with a short break in between. Neither you nor the study team will know which tablets you are taking first.
You will continue to wear your oral appliance every night. During the trial, you will have detailed overnight sleep studies (polysomnography) where small sensors track your breathing, heart rate, and brain waves while you rest. You will also be asked to complete questionnaires about your daytime sleepiness, energy levels, and overall quality of life, alongside standard blood and health checks.
Potential risks and benefits
Locations (2)
- —UnverifiedDenmark
- —UnverifiedSweden
Common questions
Do I have to stop using my mouthguard during the trial?
No. You will continue to use your custom dental splint every night throughout the study. The trial is testing the tablet in addition to your mouthguard, not instead of it.
What is a placebo?
A placebo is a dummy pill that looks and tastes identical to the real medication but contains no active ingredient. It helps researchers prove whether any improvements are truly caused by the medicine.
Will I definitely receive the real medicine?
Yes. In this 'cross-over' design, all participants take the active medicine for two weeks and the placebo for two weeks, just in a randomised (random) order.
Are overnight sleep studies uncomfortable?
Sleep studies are completely painless. They involve sticking small sensors to your skin and scalp to measure your sleep and breathing overnight in a clinic.
Can I leave the study if I feel unwell?
Yes. You can withdraw from the study at any point, for any reason, without giving an explanation and without affecting your normal healthcare.
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
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