Bronchodilators work by targeting specific receptors in the respiratory system. Beta-agonists stimulate beta-2 adrenergic receptors, leading to relaxation of bronchial muscles. Anticholinergics block the action of acetylcholine, preventing bronchoconstriction. Methylxanthines, such as theophylline, inhibit phosphodiesterase, increasing cyclic AMP levels and promoting bronchodilation.
