Asthma
Conditions
Keywords
methacholine, airway hyperresponsiveness
Brief summary
The study will assess the degree of bronchoprotection provided by the ultra long-acting beta2 agonist vilanterol against methacholine-induced bronchoconstriction.
Detailed description
This will be a double-blind, three-way crossover study comparing combination vilanterol+fluticasone with fluticasone monotherapy and a placebo (vilanterol is not available as a monotherapy). The order in which the treatments are given will be randomized and each treatment will be separated by a minimum one-week washout. Fifteen asthmatic participants will be recruited from the local community. Methacholine challenge testing (MCT) with the two-minute tidal breathing protocol will be used to quantify the bronchoprotective effects (if any) of each treatment against methacholine-induced bronchoconstriction. Each participant will undergo a total of nine methacholine challenges. After a baseline methacholine challenge, the randomized treatment (identity unknown to investigator or participant) will be administered through an Ellipta® (multi-dose dry powder inhaler). Thirty minutes following treatment administration, a second methacholine challenge will be performed. At 24 hours post-treatment, each participant must re-visit the lab for one methacholine challenge. The same process will be followed for each treatment.
Interventions
Same as vilanterol arm description
DRUGFluticasone Furoate
Same as fluticasone arm description
DRUGPlacebos
Same as placebo arm description
Sponsors
University of Saskatchewan
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
TREATMENT
Masking
TRIPLE (Subject, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* men and women aged 18 or older * stable mild-to-moderate asthma * baseline methacholine PC20 less than or equal to 8mg/mL * FEV1 greater than or equal to 65% of predicted
Exclusion criteria
* Use of long-acting anticholinergic or long-acting beta2 agonist within 30 days of study * pregnant or nursing * diabetes * hypokalemia * cardiovascular, prostate, kidney, or urinary retention problems * lactose-intolerant * allergy-induced asthma symptoms or upper respiratory tract infection within four weeks of study * current smokers * past smokers with smoking history \>10 pack years
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change from baseline methacholine PC20 (bronchoprotection) at 30 min post-treatment | baseline versus 30 min post-treatment | assessed by dose shift of geometric mean methacholine PC20 data |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Change from baseline methacholine PC20 (bronchoprotection) at 24 hours post-treatment | baseline versus 24 hours post-treatment | assessed by dose shift of geometric mean methacholine PC20 data |
Countries
Canada
Outcome results
None listed