bronkodilator

Bronchodilators are medications that relax the smooth muscle surrounding the airways, leading to dilation of the bronchial passages and improved airflow. They are primarily used to treat conditions characterized by reversible airway obstruction, such as asthma and chronic obstructive pulmonary disease (COPD), as well as acute bronchospasm from various triggers.

The main classes of bronchodilators include beta-adrenergic agonists, anticholinergics, and methylxanthines. Beta-adrenergic agonists stimulate beta-2 receptors on airway smooth muscle to induce relaxation. They are divided into short-acting (SABA), such as albuterol (salbutamol) and terbutaline, used for quick relief, and long-acting (LABA), such as salmeterol and formoterol, used for maintenance in combination therapies. Anticholinergics block muscarinic receptors to prevent bronchoconstriction; short-acting ipratropium and long-acting tiotropium are common examples. Methylxanthines, with theophylline as a representative agent, increase intracellular cyclic AMP and have a broader, less selective bronchodilating effect, but are limited by narrow therapeutic windows and interactions.

Inhalation is the preferred route for most bronchodilators because it delivers the drug directly to the airways with rapid onset and fewer systemic effects. Other routes include oral or intravenous administration, used in certain acute or severe situations. Combination therapies, such as LABA with inhaled corticosteroids or long-acting muscarinic antagonists (LAMA), are common in chronic disease management.

Common considerations include potential side effects (tachycardia, tremor with beta-agonists; dry mouth with anticholinergics), and the need for appropriate use to control symptoms and reduce exacerbations.