Medicine & USMLE


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


Montelukast is a medication used to treat asthma. It is a long-acting drug used as maintenance therapy to prevent asthma attacks from occurring. Due to this long and slow course of action, it is not a rescue medication and should not be taken during an acute asthma attack. Montelukast comes in a tablet form that is either chewed or swallowed - unlike most other asthma medications, it is not inhaled.

Key Points

  • Montelukast (Singulair)
    • Mechanism
      • Leukotriene receptor blocker
        • Binds with leukotriene receptors to promote bronchodilation, reduce inflammation, and suppress mucus production
    • Clinical Use
      • Asthma
        • For prophylactic and maintenance use
        • Should not be used during an acute attack; not a rescue medication
        • For maintenance, take once daily at bedtime
        • Administered as an oral tablet, it is not inhaled
      • Allergic rhinitis
    • Side Effects and Adverse Reactions
      • Depression, suicidal ideation