Pharmacotherapy for allergic rhinitis: a critical review of leukotriene receptor antagonists compared with other treatments

Objective: To review the mechanisms and clinical efficacy of leukotriene receptor antagonists, which are investigational therapies for allergic rhinitis, compared with intranasal corticosteroids and nonsedating antihistamines, which are the most commonly prescribed pharmacotherapies for allergic rhinitis. Data Sources: Computer-assisted MEDLINE searches for articles and manual searches of conference proceedings on intranasal corticosteroid, antihistamine, leukotriene receptor antagonist, leukotriene modifier, zafirlukast, montelukast, allergic rhinitis, rhinitis, and asthma. Selection: Published articles and pertinent abstracts on the topics identified above were selected. Head-to-head comparator trials as well as data from placebo-controlled trials were selected. Results and Conclusions: The studies published to date demonstrate that leukotriene receptor antagonists are sometimes more effective than placebo, are no more effective than nonsedating antihistamines, and are less effective than intranasal corticosteroids in the treatment of allergic rhinitis. The combination of a leukotriene receptor antagonist and an antihistamine has not been proven to be more effective than either agent alone. This review reveals several inconsistencies that require resolution. First, whereas leukotriene receptor antagonists are predicted on the basis of their mechanism of action to improve nasal congestion significantly, clinical studies reveal leukotriene receptor antagonists to be no better than antihistamines at improving congestion. Second, leukotriene receptor antagonists would not be expected on the basis of their putative mechanism of action or nasal challenge data to improve significantly sneezing, nasal itching, or drainage. However, some studies show improvement in these symptoms during treatment with leukotriene receptor antagonists. Considered in aggregate, the data available to date do not clearly support a unique role of leukotriene receptor antagonists in the treatment of allergic rhinitis whether or not it is accompanied by asthma.