Mechanism of action of zileuton:-

Zileuton is a selective and specific inhibitor of 5-lipoxygenase, preventing the formation of both LTB4 and the cysteinyl leukotrienes. Because zafirlukast and montelukast are selective antagonists of the cysteinyl leukotriene- 1 receptor, they block the effects of cysteinyl leukotrienes. All three drugs are approved for the prevention of asthma symptoms. While zafirlukast and montelukast both inhibit the effects of leukotrienes, they do so by blocking the receptor itself. Cromolyn inhibits mast cell degranulation and the release of histamine. Theophylline is a bronchodilator that has no effect on leukotrienes. Lipooxygenase inhibitors Zileuton inhibits synthesis of LTB4 (chemotactic) and LTC4 and LTD4 (bronchoconstrictor). Limiting features of this drug are sho duration of action and hepatotoxicity.