Question

Ms. Thomas, age 45, is being seen in the physician's office today for complaints of a dry, hacking cough that is keeping her up at night. The physician prescribes Dextromethorphan for the cough. Which statement is true about Dextromethorphan?

A. It works on the receptors in the throat to prevent a cough.
B. It works by relaxing the smooth muscles in the bronchioles.
C. It works in the medulla to suppress the cough reflex
D. It works by inhibitng allergen response

Answer 1

Dextromethorphan works in the medulla to suppress the cough reflex, and is used as a cough suppressant in many OTC cold and cough medications. Its effectiveness can be questionable, especially in children, and is not recommended for certain conditions like COPD or chronic bronchitis.

Step-by-step explanation:

Among the options provided regarding how Dextromethorphan works to relieve coughing, the correct statement is that it works in the medulla to suppress the cough reflex (Option C). Dextromethorphan, which is an ingredient in many over-the-counter cold and cough medications, suppresses the cough reflex by acting on the cough center in the brain, specifically the medulla. It does not work by acting on receptors in the throat, by relaxing the smooth muscles of the bronchioles, or by inhibiting the allergen response.

Clinical studies and guidelines suggest that the effectiveness of cough medications, including Dextromethorphan, can be questionable, particularly in children. Furthermore, while it may be somewhat effective in diminishing cough in adults with viral upper respiratory infections, medical authorities generally do not recommend OTC cough suppressants for conditions like COPD, chronic bronchitis, or for the treatment of whooping cough.