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Salbutamol, Pharmacogenetics and Breathing Mechanics

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ClinicalTrials.gov Identifier: NCT01903785
Recruitment Status : Completed
First Posted : July 19, 2013
Last Update Posted : November 2, 2016
World Anti-doping Agency
Information provided by (Responsible Party):
University of British Columbia

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.

Condition or disease Intervention/treatment Phase
Bronchoconstriction Inhaled Salbutamol Cycling Performance Drug: Salbutamol Drug: Placebo Phase 4

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 94 participants
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double (Participant, Investigator)
Primary Purpose: Basic Science
Official Title: The Pharmacogenetic Effects of Inhaled Salbutamol on Breathing Mechanics and Cycling Performance
Study Start Date : May 2013
Actual Primary Completion Date : December 2014
Actual Study Completion Date : August 2016

Resource links provided by the National Library of Medicine

Arm Intervention/treatment
Experimental: Salbutamol
400ug of salbutamol (one single inhalation) will be inhaled 60min prior to the begin of a time trial. Mean power output during the following 10km time trial will be described to 1600ug salbutamol and placebo.
Drug: Salbutamol
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.
Other Name: ventolin

Placebo Comparator: Placebo
400ug of placebo (one single inhalation) will be inhaled 60min prior to the begin of a time trial. Mean power output during the following 10km time trial will be described to 400ug and 1600ug salbutamol.
Drug: Placebo

Primary Outcome Measures :
  1. The effect of inhaled salbutamol on mean power output during cycling performance in female and male athletes [ Time Frame: Mean 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.

  2. The effect of inhaled salbutamol on work of breathing (WOB) and expiratory flow limitation (EFL) in female and male athletes [ Time Frame: WOB 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 Outcome Measures :
  1. The effect of inhaled salbutamol on minute ventilation in asthmatic and non-asthmatic trained, female and male cyclists [ Time Frame: Minute 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). ]

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Ages Eligible for Study:   19 Years to 45 Years   (Adult)
Sexes Eligible for Study:   All
Accepts 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

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT01903785

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Canada, British Columbia
Environmental Physiology Laboratory, University of British Columbia
Vancouver, British Columbia, Canada, V6T 1Z1
Sponsors and Collaborators
University of British Columbia
World Anti-doping Agency
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Principal Investigator: Michael S Koehle, MD, PhD University of British Columbia
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Responsible Party: University of British Columbia
ClinicalTrials.gov Identifier: NCT01903785    
Other Study ID Numbers: H09-01154-A009
First Posted: July 19, 2013    Key Record Dates
Last Update Posted: November 2, 2016
Last Verified: October 2016
Keywords provided by University of British Columbia:
exercise-induced bronchoconstriction (EIB)
inhaled salbutamol
performance enhancing
Additional relevant MeSH terms:
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Respiratory Aspiration
Respiration Disorders
Respiratory Tract Diseases
Pathologic Processes
Bronchodilator Agents
Autonomic Agents
Peripheral Nervous System Agents
Physiological Effects of Drugs
Anti-Asthmatic Agents
Respiratory System Agents
Tocolytic Agents
Reproductive Control Agents
Adrenergic beta-2 Receptor Agonists
Adrenergic beta-Agonists
Adrenergic Agonists
Adrenergic Agents
Neurotransmitter Agents
Molecular Mechanisms of Pharmacological Action