In the treatment of asthma, what is the main therapeutic action of beta-agonists?

In the treatment of asthma, beta-agonists primarily function as bronchodilators, meaning their main therapeutic action is to relieve bronchospasm. When asthma is triggered, the smooth muscles surrounding the airways constrict, leading to difficulty in breathing. Beta-agonists stimulate beta-adrenergic receptors in these muscles, resulting in relaxation and dilation of the airways. This effect helps to alleviate symptoms such as wheezing, shortness of breath, and chest tightness, enabling better airflow and improved breathing for individuals experiencing an asthma attack or chronic symptoms.

While other options may have some relevance to asthma treatment—such as decreasing mucus production or lowering airway inflammation—the immediate and significant effect of beta-agonists is their ability to relax the bronchial muscles and deflate the airways, which is essential for immediate symptom relief in asthma management.