Medicine & USMLE


Respiratory Drugs
  1. Beta-2 Agonists (Albuterol, Salmeterol)
  2. Cromolyn
  3. Montelukast
  4. Guaifenesin
  5. Ephedrine / Phenylephrine
  6. Acetylcysteine
  7. Theophylline


Guaifenesin, commonly known as Mucinex, is an expectorant, meaning it is a mucus thinner. This makes it useful in treating congestion and productive cough. It should be taken with a full glass of water.

Key Points

  • Guaifenesin (Mucinex)
    • Mechanism
      • Expectorant (mucus thinner)
        • Helps thin mucus and other bronchial secretions so they can be eliminated by coughing
        • Should be taken with a full glass of water
          • Taking plenty of fluids will also help thin secretions
    • Clinical Use
      • Cough and Congestion
        • Pneumonia with productive cough
        • Bronchitis
        • The common cold
        • Often combined with antitussives (e.g. dextromethorphan) or decongestants
        • Assess the cough type and mucus characteristics
    • Side Effects and Adverse Reactions
      • GI upset
      • Drowsiness, dizziness
      • Headache