Reversal of Acute β-Blocker Induced Bronchoconstriction

Current therapies for the management of asthma include inhalers. Types of these medications (beta agonists), improve asthma symptoms by stimulating areas (receptors) within the human airway resulting in dilation of the human airway. Whilst these drugs are highly effectively in the immediate setting their longterm use, constantly stimulation of receptors within the airway has been associated with increased asthma exacerbations and rare cases of death. Conversely medications that block receptors within the human airway (betablockers)have been avoided in asthma. The main reason for this is because of the possible acute airway narrowing that can occur after soon after administration. However chronic use of betablockers in asthma has recently been shown to be of benefit in reducing airway inflammation which is of great importance in improving asthma control and reducing symptoms. Despite this early evidence supporting chronic use of beta blockers in asthma, there is concern in 2 major regards:their potential to cause acute airway narrowing (irrespective of longterm benefit) and the possibility that they could block the reliever action of beta agonists. The objective of this study is to establish how best to reverse the short term effects of a single dose of beta blocker. This study is designed as a single centre study, with participants attending the department on approximately 3 separate visits (including a screening visit) at approximately 1 weekly intervals.