Guaifenesin (Mucinex) is best described as an:

• A. Antitussive that suppresses coughing
• B. Bronchodilator that opens airways
• C. Mucolytic that breaks down mucus strands
• D. Expectorant that increases respiratory secretions and thins secretions to facilitate expectoration

Answer: (D)

Guaifenesin is an expectorant. Its main effect is to increase respiratory secretions and thin mucus, making it easier to clear the airways by coughing. By boosting the volume of mucus and reducing its viscosity, secretions are loosened and can be expelled more readily, which relieves chest congestion. It does not suppress the cough reflex, so it isn’t an antitussive. It doesn’t act as a bronchodilator to open airways, and it isn’t a mucolytic that chemically breaks down mucus strands. The general idea is that it either reflexively or by hydrating mucus, makes secretions less thick and easier to expectorate.