Which statement best describes the mechanism of action of albuterol?

Which statement best describes the mechanism of action of albuterol?

• A. It is a leukotriene receptor antagonist
• B. It is a mast cell stabilizer
• C. It is a systemic antibiotic
• D. It is a beta-2 adrenergic receptor agonist causing bronchodilation

Answer: (D)

Albuterol works by stimulating beta-2 adrenergic receptors on the smooth muscles of the airways. This activates a Gs protein–coupled pathway that increases adenylyl cyclase activity and raises cyclic AMP levels. Higher cAMP in airway smooth muscle leads to relaxation of the muscles, causing bronchodilation and relief of bronchospasm. It’s a fast-acting inhaled medication used as a rescue therapy for acute asthma symptoms or bronchoconstriction. This mechanism is distinct from other drug actions: a leukotriene receptor antagonist blocks inflammatory mediators, a mast cell stabilizer prevents release of mediators from mast cells, and a systemic antibiotic treats infections. Side effects like tremor and palpitations can occur due to systemic beta stimulation, especially at higher doses.

Albuterol works by stimulating beta-2 adrenergic receptors on the smooth muscles of the airways. This activates a Gs protein–coupled pathway that increases adenylyl cyclase activity and raises cyclic AMP levels. Higher cAMP in airway smooth muscle leads to relaxation of the muscles, causing bronchodilation and relief of bronchospasm. It’s a fast-acting inhaled medication used as a rescue therapy for acute asthma symptoms or bronchoconstriction.

This mechanism is distinct from other drug actions: a leukotriene receptor antagonist blocks inflammatory mediators, a mast cell stabilizer prevents release of mediators from mast cells, and a systemic antibiotic treats infections. Side effects like tremor and palpitations can occur due to systemic beta stimulation, especially at higher doses.