Question

A 75-year-old male emphysema patient presents to the ED because of increasing dyspnea and shortness of breath with exertion. He is a 50 pack/year smoker and has a thin wasted appearance. After strongly urging him to enter a smoking cessation program, he is prescribed albuterol. What is the mechanism of action of albuterol?

Inhibition of phosphodiesterase (PDE), the enzyme that degrades cAMP to AMP
Competitively blocks muscarinic receptors in the airways
Stimulation of adenylyl cyclase increasing cAMP in smooth muscle cells
Inhibition of pulmonary secretion viscosity by splitting disulfide linkages between mucoprotein complexes
Inhibition of arachidonic acid synthesis and expression of COX-2

Answer 1

Albuterol works by stimulating adenylyl cyclase in smooth muscle cells, raising cAMP levels and causing bronchodilation to ease breathing in emphysema and asthma patients.

Step-by-step explanation:

The mechanism of action of albuterol, which is prescribed to treat conditions like emphysema and asthma, involves stimulating adenylyl cyclase in the smooth muscle cells of the airways. This stimulation leads to an increase in the levels of cyclic adenosine monophosphate (cAMP), which in turn results in the relaxation of bronchial smooth muscles and bronchodilation. Albuterol thus helps alleviate symptoms such as dyspnea and shortness of breath by improving airflow.