Which drug is a beta-adrenergic agonist used to treat bronchospasm?

Which drug is a beta-adrenergic agonist used to treat bronchospasm?

• A. Lidocaine
• B. Diphenhydramine
• C. Furosemide
• D. Albuterol

Answer: (D)

Bronchodilators that address bronchospasm work by stimulating beta-adrenergic receptors on airway smooth muscle, which raises cAMP and causes the muscles to relax, opening the airways. Albuterol is a classic short-acting beta-2 adrenergic agonist used for rapid relief of bronchospasm in asthma and other obstructive airway conditions. When inhaled, it quickly binds to beta-2 receptors in the lungs, leading to smooth muscle relaxation and dilated airways, so wheezing and shortness of breath improve promptly. Inhaled forms are preferred to limit systemic effects, though higher doses can cause tremor or a fast heartbeat because of some beta-1 activity at higher concentrations. The other drugs listed don’t target airway smooth muscle this way: lidocaine is a local anesthetic/antiarrhythmic, diphenhydramine is an antihistamine, and furosemide is a diuretic—none primarily treat bronchospasm.

Bronchodilators that address bronchospasm work by stimulating beta-adrenergic receptors on airway smooth muscle, which raises cAMP and causes the muscles to relax, opening the airways. Albuterol is a classic short-acting beta-2 adrenergic agonist used for rapid relief of bronchospasm in asthma and other obstructive airway conditions. When inhaled, it quickly binds to beta-2 receptors in the lungs, leading to smooth muscle relaxation and dilated airways, so wheezing and shortness of breath improve promptly. Inhaled forms are preferred to limit systemic effects, though higher doses can cause tremor or a fast heartbeat because of some beta-1 activity at higher concentrations. The other drugs listed don’t target airway smooth muscle this way: lidocaine is a local anesthetic/antiarrhythmic, diphenhydramine is an antihistamine, and furosemide is a diuretic—none primarily treat bronchospasm.