Salbutamol is a highly selective, short-acting beta-2 (β₂) adrenergic receptor agonist engineered for immediate respiratory relief. It functions by targeting and binding to the β₂-adrenergic receptors located predominantly on airway smooth muscle cells. This binding activates the Gs-protein-coupled adenylyl cyclase pathway, causing a rapid increase in intracellular cyclic adenosine monophosphate (cAMP). The surge in cAMP activates protein kinase A, which decreases intracellular calcium levels and triggers prompt, high-potency relaxation of the bronchial smooth muscles. This mechanism physically opens narrowed airways within minutes, reduces respiratory resistance, and keeps the pulmonary channels systemically clear during acute asthmatic or wheezing episodes.