Medicine & USMLE


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


Cromolyn is a medication used to treat asthma. It is a slow-acting drug, meaning that it does not work as a rescue medication, but is instead used for long-term maintenance therapy of asthma. It can also be used to treat seasonal allergies, or allergic rhinitis. If cromolyn is suddenly stopped, it might result in rebound bronchospasm. To avoid this, the medication should be tapered off slowly.

Key Points

  • Cromolyn
    • Mechanism
      • Mast cell stabilizer
        • Inhibits release of histamine from mast cells to prevent an asthma attack
      • Administered through inhalation
    • Clinical Use
      • Asthma
        • Long-term management
        • Is not used for acute asthma attacks; not a rescue medication
        • Exercise-induced asthma
          • Take 10-15 minutes prior to exercise
        • Considered second-line treatment
      • Allergic rhinitis (seasonal allergies)
      • Mastocytosis
    • Side Effects and Adverse Reactions
      • Rebound bronchospasm
        • Should not be abruptly discontinued
      • Postnasal drip
      • Nose and throat irritation
      • Cough