Introduction: The prevalence of asthma and exercise-induced bronchoconstriction is high in the athletic population. In endurance sport, the prevalence has been reported to be as high as 30-50% compared to the general population prevalence of approximately 5-10% in Western countries. First-line treatment in asthma is reliever medication and inhaled corticosteroids (ICS). Therefore, β2-adrenoceptor agonists and ICS are commonly prescribed drugs to athletes. Although long-acting β2-agonists (LABA) are the most commonly used β2-agonists in asthma management, development of ultra-long acting β2-agonists (U-LABA) as vilanterol may change this. U-LABA has a long duration of action (24 hours) compared with LABA (12 hours). The accumulated number of inhalations per day for elite athletes may thus be reduced when prescribed with U-LABA as compared to LABA. Use of β2-agonists are restricted by the World Anti-Doping Agency (WADA). As of 2018, β2-agonists salbutamol, formoterol and salmeterol are allowed by inhalation in therapeutic doses, whereas other β2-agonists, such as terbutaline and vilanterol still require the athlete to obtain a therapeutic use exemption (TUE). To discriminate therapeutic use from supra-therapeutic misuse, WADA has established urinary thresholds and decision limits based on urine concentrations of salbutamol, salmeterol and formoterol. However, while data on urine concentrations of these three β2-agonists are well-described in studies that simulate sport-specific situations that are applicable for doping control, no such data exist for the novel U-LABA vilanterol. For instance, asthmatic athletes using β2-agonists usually inhale the drug before training or competition as prophylaxis for bronchoconstriction. Thus, studies are needed to investigate the urine concentrations of vilanterol after inhaled administration in set-ups that are applicable to doping control which this study aims to investigate. Method: The study is divided in two phases. The first phase consists of a pharmacokinetic pilot trial (EXP1). Depending on the analytical outcome of the pilot study, the study proceeds into the second phase, which is a larger pharmacokinetic trial (EXP2). Both EXP1 and EXP 2 are open label studies. EXP1: 6 healthy, well trained individuals are recruited to perform two trial days. First trial day consists of inhalation of the study drug in 4 times therapeutic dose followed by an exercise session. Before second trial day subjects inhales 4 times the therapeutic dose at home and on day 7 perform a training session. Urine and blood are collected in the following 72 hours both days. EXP2: 20 healthy, well trained individuals are recruited to perform four trial days in the same way as EXP1. But here both normal use and four times normal dose is investigated.
See this in plain English?
AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.
Vilanterol and its metabolites
Timeframe: 72 hours post drug administration
Vilanterol and its metabolites
Timeframe: 0-10 hours post drug administration