Leukotriene Inhibitors- Zileuton, Montelukast, Zafirlukast

The formation of leukotrienes depends on lipoxygenation of arachidonic acid by 5-lipoxygenase.
Zileuton is a potent and selective inhibitor of 5-lipoxygenase activity and thus inhibits the formation of all 5-lipoxygenase products.
Thus, in addition to inhibiting the formation of the cys-LTs,
zileuton also inhibits the formation of leukotriene B4 (LTB4), a potent chemotactic autacoid
They are used only for prophylactic purpose in mild to moderate asthma