Snapshot A 13-year-old girl with a history of asthma presents to her pediatrician with increasing shortness of breath. She has been using a low-dose fluticasone/salmeterol inhaler daily with good control of symptoms for the past year. However, she recently joined the track team and has been needing to use her albuterol regularly since starting daily track practice. She is prescribed montelukast. (Moderate persistent asthma) Overview One of seven medications used for asthma aimed to reduce inflammation and obstruction corticosteroids beta-agonists muscarinic antagonists methylxanthines cromolyn antileukotrienes omalizumab Antileukotrienes Mechanism of action inhibit 5-lipoxygenase to reduce the synthesis of leukotrienes from arachidonic acid example: meclofenamate sodium and zileuton antagonize leukotriene receptor example: montelukast, zafirlukast, and pranlukast Clinical use chronic asthma persistent asthma aspirin-induced asthma exercise-induced bronchoconstriction chronic obstructive pulmonary disease mast cell activation syndrome Adverse effects suicidality hypersensitivity zafirlukast increases the anticoagulant effect of warfarin