Condition category
Date applied
Date assigned
Last edited
Retrospectively registered
Overall trial status
Recruitment status

Plain English Summary

Background and study aims
Wheezing is a whistling sound caused by breathing through narrowed airways. It is a common problem in young children. Many preschool children have repeated wheezy episodes, and share characteristics with older children who have asthma. Like them, they are often treated with inhaled salbutamol. However, in the preschool years it is difficult to make a definite diagnosis of asthma, and there is much less consensus about treatment. The correct dose of inhaled salbutamol has been determined in adults and older children by studying their response to a range of doses. This has not been possible in children below 7 years of age who are unable to cooperate with the tests. Doctors commonly ask parents to use any dose between 200 to 1000 micrograms of salbutamol to help their child's wheezy spells. Recently, however, a lung function test that could be used for this purpose has been validated in young children. This study proposes to use this test (Rint) to find the correct dose range that produces an adequate response in most young children. Recent work also suggests that even large doses of salbutamol may not be effective in relieving symptoms in some children. We will define the extent of this problem, as there are alternative 'relievers' that could then be used to help these children. We will also explore whether a simple genetic test that could predict this lack of response.

Who can participate?
Children aged 2 years 6 months to 6 years 11 months, with recurrent wheeze (at least 3 episodes of wheezing over the previous 12 months)

What does the study involve?
Participants are randomly allocated to inhale one of four different doses of salbutamol. Lung function is tested before and 20 minutes after inhaling salbutamol. Saliva and urine samples are also collected. The one-off study visit lasts for around two and half hours and there is no follow up.

What are the possible benefits and risks of participating?
Involvement in the study and the resulting discussions may provide the parent/carer and child with a greater understanding of the processes causing wheeze. This study does not have any risk of physical or psychological harm, and there are no painful procedures. Some young children are bothered by the clicking sounds during the breathing test, so we spend a little time beforehand getting them used to the equipment. The researchers work with the parents to distract them during the measurements. The collection of the urine and saliva samples does not involve any risks to the child. Travel expenses to the hospital (up to £20) for the research study visit can be reimbursed.

Where is the study run from?
Royal Sussex County Hospital (UK)

When is the study starting and how long is it expected to run for?
January 2014 to June 2017

Who is funding the study?
National Institute for Health Research (UK)

Who is the main contact?
Gemma Earl

Trial website

Contact information



Primary contact

Mrs Gemma Earl


Contact details

Clinical Investigation and Research Unit
Royal Sussex County Hospital
Eastern Road
United Kingdom

Additional identifiers

EudraCT number

2014-001978-33 number

Protocol/serial number


Study information

Scientific title

How can we optimise inhaled beta2 agonist dose as 'reliever' medicine for wheezy preschool children?



Study hypothesis

The study will help develop the evidence for the correct dose of salbutamol in younger children with recurrent wheeze who have been prescribed salbutamol by their doctor. It is possible that a small dose of salbutamol, such as 2 puffs (200 μg) is adequate for most of these children. If this is the case, larger doses such as 1000 μg, should not be prescribed (as is current practice) as they may be inducing side-effects in these children. Secondly, some younger children who currently prescribed larger doses of salbutamol may in fact be 'poor‘ or 'non-responders' to salbutamol due to their genetic constitution. Such children may benefit from alternative 'reliever' medicines, such as ipratropium or montelukast. We intend to investigate whether an effective marker can be identified for poor salbutamol efficacy in these younger children.

Ethics approval

East of Scotland Research Ethics Service REC 2 , 21/07/2014, ref: 14/ES/0072

Study design

Randomised; Interventional; Design type: Treatment

Primary study design


Secondary study design

Randomised controlled trial

Trial setting


Trial type


Patient information sheet

Not available in web format, please use contact details to request a patient information sheet


Topic: Children; Subtopic: All Diagnoses; Disease: All Diseases


1. Collection of DNA sample using non-invasive Oragene DNA Collection kits
2. Collection of urine sample after each of the two doses of salbutamol will be attempted
3. Data Collection
4. Rint Measurements: At baseline and 20 minutes after each of the two doses of salbutamol
5. Salbutamol Doses: No control group. Participants are randomised to 1 of 4 dosage schedules:
5.1. 100 μg Salbutamol →+300 μg = 400 μg Salbutamol
5.2. 100 μg Salbutamol →+500 μg = 600 μg Salbutamol
5.3. 200 μg Salbutamol →+600 μg = 800 μg Salbutamol
5.4. 200 μg Salbutamol →+200 μg = 400 μg Salbutamol
The one off study visit lasts for around two and half hours. No follow up.

Intervention type



Not Applicable

Drug names


Primary outcome measures

Bronchodilator response to salbutamol using lung function test (interrupter resistance Rint) at baseline and 30 minutes after each dose of salbutamol.

Secondary outcome measures


Overall trial start date


Overall trial end date


Reason abandoned


Participant inclusion criteria

1. Age 2 years 6 months to 6 years 11 months
2. Recurrent wheeze, defined as at least 3 episodes of wheeze over the previous 12 months by the parent

Participant type


Age group




Target number of participants

Planned Sample Size: 155; UK Sample Size: 155

Participant exclusion criteria

1. Other major airway or lung disease, e.g. chronic lung disease of prematurity, cystic fibrosis, and abnormal airway anatomy
2. Recent (within 2 weeks) treatment with systemic corticosteroids or leukotriene inhibitors
3. Participants involved in other research currently or recently

Recruitment start date


Recruitment end date



Countries of recruitment

United Kingdom

Trial participating centre

Royal Sussex County Hospital
Clinical Investigation and Research Unit, Eastern Road
United Kingdom

Sponsor information


Brighton and Sussex University Hospitals NHS Trust

Sponsor details

Royal Sussex County Hospital
Eastern Road
United Kingdom

Sponsor type

Hospital/treatment centre



Funder type


Funder name

National Institute for Health Research

Alternative name(s)


Funding Body Type

government organisation

Funding Body Subtype

Federal/National Government


United Kingdom

Results and Publications

Publication and dissemination plan

A research summary will be provided to participants if they request to be made aware of this. Trial results will be communicated to healthcare professionals, the public and other relevant groups at conferences, press releases, through published papers and via parent groups. The full protocol will be published on the online journal

Intention to publish date

Participant level data

Not expected to be available

Results - basic reporting

Publication summary

Publication citations

Additional files

Editorial Notes

09/06/2016: Plain English summary added.