Salbutamol, Pharmacogenetics and Breathing Mechanics

University of British Columbia

Status and phase: Completed; Phase 4

Conditions: Cycling Performance; Inhaled Salbutamol; Bronchoconstriction

Treatments: Drug: Placebo; Drug: Salbutamol

Study type: Interventional

Funder types: Other

Identifiers

NCT01903785

H09-01154-A009

Details and patient eligibility

About

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.

Enrollment: 94 patients

Sex: All

Ages: 19 to 45 years old

Volunteers: Accepts Healthy Volunteers

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

Trial design

Primary purpose: Basic Science

Allocation: Randomized

Interventional model: Crossover Assignment

Masking: Double Blind

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94 participants in 2 patient groups, including a placebo group

Salbutamol

Experimental group

Description:

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.

Treatment:

Drug: Salbutamol

Placebo

Placebo Comparator group

Description:

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.

Treatment:

Drug: Placebo