Skip to content

Salbutamol, Pharmacogenetics and Breathing Mechanics

The Pharmacogenetic Effects of Inhaled Salbutamol on Breathing Mechanics and Cycling Performance

Status
Completed
Phases
Phase 4
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT01903785
Enrollment
94
Registered
2013-07-19
Start date
2013-05-31
Completion date
2016-08-31
Last updated
2016-11-02

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Bronchoconstriction, Cycling Performance, Inhaled Salbutamol

Keywords

exercise-induced bronchoconstriction (EIB), inhaled salbutamol, performance enhancing, cycling

Brief summary

Athletes using asthma medications called β2-agonists win a disproportionately high number of medals at Olympic Games. Due to a large variety in the genes that affect how individuals respond to β2-agonists, the investigators will look at variations in the genetic response to these medications by dividing athletes into high-responders and low-responders. The investigators will then compare athletic performance after the inhalation of β2-agonists to placebo. Furthermore, the investigators will analyze the effect of β2-agonists on breathing mechanics. Due to differences in their anatomy females may decrease the energy needed for breathing during high-intensity exercise to a greater extent compared to male athletes after the inhalation of β2-agonists.

Interventions

DRUGSalbutamol

60 minutes prior to the start of a 10km cycling time trial on a bike ergometer, subjects will inhale either 400ug of salbutamol 1600ug of salbutamol or 400ug of placebo in a randomly assigned manner in a single dose.

DRUGPlacebo

Sponsors

World Anti-Doping Agency
CollaboratorOTHER
University of British Columbia
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
BASIC_SCIENCE
Masking
DOUBLE (Subject, Investigator)

Eligibility

Sex/Gender
ALL
Age
19 Years to 45 Years
Healthy volunteers
Yes

Inclusion criteria

* trained, experienced cyclists * maximal oxygen consumption of at least 50ml/kg/min or 4l/min for women; and 60ml/kg/min or 5l/min for men * athletes with and without exercise-induced bronchoconstriction

Exclusion criteria

* any uncontrolled heart or lung condition * maximal oxygen consumption of less than 50ml/kg/min or 4L/min for women; and less than 60ml/kg/min or 5L/min for men * pregnancy * smoking

Design outcomes

Primary

MeasureTime frameDescription
The effect of inhaled salbutamol on mean power output during cycling performance in female and male athletesMean power output is assessed over the duration of a 10km time trial (start of time trial until completion of time trial) on a bike ergometer.Athletes perform a two time trials, each on a separate day. The time trials are performed 60min after the inhalation of salbutamol or placebo.
The effect of inhaled salbutamol on work of breathing (WOB) and expiratory flow limitation (EFL) in female and male athletesWOB and EFL will be assessed during an incremental exercise test. Exercise will start at 0 Watts and will then be increased every 2.5min by 30 Watts until maximal exertion.EFL and WOB will be assessed with the help of an esophageal balloon and mouth pressure.

Secondary

MeasureTime frame
The effect of inhaled salbutamol on minute ventilation in asthmatic and non-asthmatic trained, female and male cyclistsMinute ventilation will be assessed during two 10km time trials (one time trial will be started 60min after the inhalation of salbutamol, the second time trial will be started 60min after the inhalation of placebo).

Countries

Canada

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026