Medicine & USMLE


Respiratory Pharm
  1. Ipratropium vs Tiotropium
  2. 1st Generation Antihistamines
  3. 2nd-Generation Antihistamines
  4. Albuterol vs Salmeterol
  5. Fluticasone & Budesonide
  6. Montelukast & Zafirlukast
  7. Zileuton
  8. Omalizumab
  9. Cromolyn & Nedocromil
  10. Guaifenesin
  11. Endothelin Receptor Antagonists (Bosentan)
  12. Prostaglandin Analogs (Epoprostenol, Iloprost)
  13. Theophylline


Zileuton is an antiinflammatory drug sometimes used to treat asthma. It works by blocking the enzyme 5-LOX, which reduces the production of leukotrienes from arachidonic acid. This leukotriene reduction is helpful in preventing exacerbations in patients with asthma - also known as asthma attacks. One side effect of zileuton to know is hepatotoxicity.

Key Points

  • Zileuton
    • Mechanism
      • Decreased production of leukotrienes
        • Inhibits 5-lipoxygenase (5-LOX), thereby blocking the conversion of arachidonic acid to inflammatory leukotrienes.
          • LTC4, LTD4, LTE4 cause bronchoconstriction. By inhibiting their formation, zileuton can prevent asthma episodes.  
        • Leukotrienes are synthesized from arachidonic acid via the lipoxygenase pathway. Zileuton inhibits this pathway, thus reducing leukotriene production.
    • Clinical indications
      • Asthma
        • Zileuton is used as a prophylactic therapy for asthma.
        • Lipoxygenase inhibitors (eg, zileuton) decrease production of pro-inflammatory leukotrienes and are indicated for treatment of asthma
    • Adverse effects
      • Hepatotoxicity