CompletedPhase II/IIIInterventional

Decongestants in Obstructive Sleep Apnoea (DOSA)

Obstructive sleep apnoea (OSA) happens when the throat muscles relax and block your airway during sleep, leading to broken rest and daytime tiredness. The most effective treatment is a Continuous Positive Airway Pressure (CPAP) machine, which blows air through a mask to keep the airway open. While CPAP works well, the machines are bulky and difficult to pack for holidays or short breaks. This study explores whether an over-the-counter decongestant spray (xylometazoline) can temporarily keep the airway clear. Volunteers with mild to moderate OSA stop using their CPAP machine for up to 28 days. Each night, they use either the decongestant spray or an inactive dummy spray in their nose and throat, while wearing a simple finger monitor in bed. If daytime tiredness or symptoms return, participants restart CPAP immediately. The goal is to see if decongestants could allow safe, temporary breaks from CPAP.

At a glance

Status

Completed

Phase

Phase II/III

Sponsor

University of Oxford

Enrolment target

232

Start

01 Feb 2019

Estimated completion

01 Feb 2021

Obstructive sleep apnoea

What is this study about?

Obstructive sleep apnoea (OSA) is a common condition affecting around 1 in 20 adults. During sleep, throat muscles relax and can fully or partly block the airway. This causes repeated pauses in breathing, drops in blood oxygen levels, and brief awakenings throughout the night. People with OSA often wake up feeling unrefreshed, struggle with daytime exhaustion, and may snore loudly.

The most reliable treatment for OSA is a CPAP machine, which delivers steady air pressure through a bedtime mask to keep the airway open. While CPAP transforms sleep quality and health for many, taking a large machine away on trips, weekends away, or camping can be awkward. Many patients ask if it is safe to pause their CPAP treatment for a few days at a time.

Snoring and airway blockages are often worse when the nose is blocked or the throat tissues are swollen. Nasal decongestants help shrink swollen tissues and ease breathing. Researchers at the Oxford Respiratory Trials Unit are running this study to test whether a decongestant spray applied to the nose and throat can keep breathing stable without a CPAP machine. By comparing the decongestant against a dummy spray, researchers hope to discover whether people can safely leave their CPAP machines at home for short holidays in the future.

Key takeaways

Tests whether a decongestant spray can allow safe, temporary breaks from CPAP machines.
Open to adults with mild to moderate sleep apnoea who have used CPAP regularly for at least six months.
Involves stopping CPAP for up to 28 days while using a spray and wearing a nightly sleep monitor.
Professional drivers and those with a history of sleep-related driving incidents cannot join.
If tiredness returns, participants restart their CPAP machine immediately.

Who may be eligible?

This study is designed for adults aged 18 to 85 who have been diagnosed with mild to moderate obstructive sleep apnoea. To be considered, you must have been using a CPAP machine regularly for at least six months, averaging at least four hours of use per night. Because the study relies on home tracking tools, you will also need good mobile phone reception and home Wi-Fi.

For safety reasons, some people cannot take part. You cannot participate if your job involves professional driving or other tasks where falling asleep could cause serious harm, or if you have ever had an accident caused by tiredness. People with severe lung conditions, low daytime oxygen levels, significant kidney or liver disease, or central sleep apnoea are also excluded. Finally, the study is not suitable for anyone who is pregnant, breastfeeding, or has an intolerance to fructose.

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 between 18 and 85 years old.
I have mild to moderate obstructive sleep apnoea.
I have used my CPAP machine for at least 4 hours a night over the past 6 months.
I am willing to pause my CPAP treatment for up to 28 days.
I have reliable Wi-Fi and mobile phone signal at home.
I do not drive professionally or do safety-critical work.

Answer every question to see your result.

What does participation involve?

Taking part lasts up to 28 days, during which you will pause your CPAP treatment. You will visit a local sleep clinic (in Oxford or Taunton) twice for routine health checks, nose and throat examinations, and simple lifestyle questionnaires.

Each night at bedtime, you will spray an allocated treatment into both nostrils and each side of your throat. You will be randomly assigned (like tossing a coin) to receive either the active decongestant spray or a dummy placebo spray. Every night, you will wear a small finger monitor that tracks your oxygen levels while you sleep, and you will fill in a quick electronic diary each day. If your sleep apnoea symptoms return, or if researchers notice changes on your monitor, you will restart your CPAP machine immediately. Otherwise, you will return to your CPAP machine after 28 days.

Potential risks and benefits

Taking part may not help you personally, but you will be contributing to research that could give people with sleep apnoea more freedom when travelling. The main risk is that your apnoea symptoms—especially daytime sleepiness—might return while you are not using your CPAP machine. The decongestant spray may also cause temporary side effects such as nasal dryness, irritation, or a stinging sensation in the throat. Your safety is monitored closely throughout, and you can stop the study and restart CPAP at any time without affecting your normal NHS care.

Locations (2)

Some site locations are approximate. We're improving this — please verify with the trial team before travelling.

Taunton and Somerset NHS Foundation Trust
City only
Taunton, England
Oxford Respiratory Trials Unit
City only
Oxford, England

Common questions

Will I definitely receive the active decongestant spray?

No. You will be randomly assigned to receive either the decongestant spray or a matching dummy (placebo) spray. Neither you nor the study team can choose which one you receive.

What happens if I start feeling tired during the day?

If you notice your sleepiness returning, you must report it right away. The study team will advise you to restart your CPAP machine immediately for your safety.

Can I drive while taking part in this trial?

Professional drivers cannot join the study. If you drive socially, you must not drive if you feel tired or drowsy at any point during your time off CPAP.

Is this spray meant to replace my CPAP machine forever?

No. The spray is only being tested as a temporary option for short breaks, such as a holiday, and is not a permanent replacement for CPAP therapy.

How many hospital visits are required?

You will only need to attend two clinic visits at the sleep centre. The rest of the study takes place in the comfort of your own home.

How to find out more

Emma Hedley

emma.hedley@ouh.nhs.uk +44 (0)1865 225205 Official trial record

Always speak to your GP or specialist before deciding to take part in a study.