Beta 2 (b2) agonists are the most common type of bronchodilator used to treat asthma. Beta 2 (b2) agonists are agents that bind to b2 receptors and cause muscle relaxation of the airways. There are different variants of the gene (genotypes) that influence how b2 agonists perform among the population.
A recent study demonstrated that patients with mild asthma and the Arg/Arg variant at the 16th amino acid position have improved lung function and asthma control when albuterol (Proventil-HFA), a short acting b2 agonist, is replaced with a different class of bronchodilator. The investigators plan to study asthma patients with distinct genetic makeups of the b2 receptor; specifically Arg/Arg and Gly/Gly.
Throughout the treatment period, patients will be instructed to use ipratropium bromide (Atrovent-HFA), a bronchodilator which works through a different mechanism for rescue therapy; albuterol will be available for use if necessary.
The goal of this study is to determine if the withdrawal of a beta 2 agonist leads to improved asthma control in those asthmatic patients with the Arg/Arg genotype compared with those with the Gly/Gly genotype.
