Other drugs Leukotriene inhibitors (eg, montelukast, zafirlukast, zileuton) are indicated for treatment of the following (see also table Drug Treatment of Asthma): Mild persistent asthma; Montelukast, zafirlukast, or zileuton Seasonal allergic rhinitis: Montelukast Urticaria: Montelukast or zafirlukast Anti-IgE antibody (omalizumab) is indicated for the following: Moderately persistent or severe asthma refractory to standard treatment Chronic idiopathic urticaria refractory to antihistamine therapy Nasal polyps Immunotherapy Exposure to allergen in gradually increasing doses (hyposensitization or desensitization) via injection or orally or in high doses sublingually can induce tolerance.