Two major categories of bronchodilators used in COPD include

• A. Corticosteroids and antibiotics
• B. Diuretics and ACE inhibitors
• C. Opioid antagonists and calcium channel blockers
• D. Beta-2 adrenergic agonists (SABAs and LABAs) and anticholinergics

Answer: (D)

Bronchodilators work by relaxing the smooth muscle around the airways to open them up and improve airflow in COPD. The two main categories used are beta-2 adrenergic agonists and anticholinergics. Beta-2 agonists (short-acting for quick relief and long-acting for maintenance) stimulate receptors on airway smooth muscle to produce rapid, sustained bronchodilation. Anticholinergics block acetylcholine at muscarinic receptors, reducing vagal-induced bronchoconstriction and providing steady bronchodilation, often used for maintenance. Other drug types listed don’t directly dilate the airways—corticosteroids mainly reduce inflammation, antibiotics treat infections, diuretics and ACE inhibitors aren’t bronchodilators, and opioid antagonists or calcium channel blockers aren’t standard COPD bronchodilators.